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Digital Control Unit (DCU) Manual

1. Disp ENTER MIN TEMP Input W The value typed in will be stored in variable W Later in the program the program goes into a data collection loop To allow the user to specify when the data collection loop should end the following code is used Lbl A getKey K If K 95 Goto A Keycode 95 represents the key on a TI 83 calculator The loop will repeat until this key is pressed An alternative way to allow the user to control when data collection ends would be to use the statement below While getKey 0 data collection code here End In this example the data collection code will be repeated until any key is pressed 25 Digital Control Unit User s Manual Subroutines We have also included a number of small subroutines on the CD for you to use On the TI calculators these are actually separate programs which we refer to as subprograms These subroutines are intended to supply sections of code that you can use to write your programs Major operations that you want your program to handle can be replaced using one of the subroutines Many programs can be written by linking together these subroutines with a few lines of new code As an example consider the program DCUTRAP2 As mentioned earlier this program is used to make a bug trap It uses a photogate to sense when a bug is inside a box It then turns on a motor to knock the lid of the box closed Here is a generic description of this program with some comments explaining
2. Digital Control Unit User s Manua Two Digital Output Lines Used to Run a Motor in Two Directions For connecting electrical devices we provide a cable which connects to the 9 pin sub D socket on the side of the DCU There are connections for all six digital lines plus power and ground The color code of the six wires are labeled on the cable There are wires for each of the six digital output lines two ground wires and a wire labeled connected to the power from line Details on the DCU connector and power and current limitations can be found in the Connecting Devices to the DCU section of this manual Analog Output Overview This version of the DCU manual includes instructions on how to use the analog output line of the Vernier LabPro interface You can connect to this line by using the Voltage Probe which comes with every LabPro VP BTA Connect it to the CH4 connector Note that the analog output line is not available on the CBL 2 interface Unlike the digital output lines of the DCU the analog output line can be set at any voltage from 4 to 4 volts and it can even be used as a function generator You can set a voltage output waveform to sine triangle ramp up ramp down or square wave One command sets the output level or pattern Sample analog output programs are provided on the DCU CD The DCU Sample Programs CD Sample programs for controlling the DCU are provided on the CD that comes with the packag
3. The sample program above highlights the difference between the high level and low level subVIs In this program line D1 is turned on for five seconds configured by double clicking the Dig Out Direct Express VJ then line 2 is turned on for five seconds 5000 milliseconds and then lines one and two are turned on for five seconds remember that sending a 3 turns on lines and 2 In every instance a 2001 string command is sent to the LabPro The actions outputs are isolated in the diagrams below With the first output the s 2001 1 command is completely hidden within the Express VI Someone could write a program using this Express VI to turn on the digital lines without knowing anything about a 2001 command string In the second output the 2001 command is partially hidden The user inputs a 2 as a string not a number and this gets concatenated within the subVI to create the s 2001 2 command string In the third output the user must create the entire command string This means unlike the Express VI the user must have some knowledge of the LabPro commands ry FFF x v Dig Out Direct_2 Source vi Comm port Comm port out Error In Error Out ia First output using Express VI Second output using subVI Third output using LabPro command The LabPro palette contains both the high level and low level VIs to provide for programming flexibility and to match the type of programmin
4. DCU Programs Move the folder named LabPro to the user lib folder that is found in the National Instruments LabVIEW directory The LabPro folder contains the subVIs that are used in all of the DCU VIs we provide None of the VIs we provide will work unless you have this folder 2 Move the folder named DCU Programs to a convenient location on your hard drive 3 Read the notes below to confirm that you have the appropriate USB or Serial drivers installed If you will be using a USB connection from the LabPro you may need to install a USB driver e Windows You need to install USB drivers unless you have previously installed the Vernier program Logger Pro 3 3 If you do not have Logger Pro 3 3 already installed on your computer then run the LabPro USB Installer You can find this installer at www vernier com drivers e Mac OS X You must have the USB driver installed We do not have an installer for the Mac OSX driver Therefore you must have Logger Pro 3 3 installed Installing a demo version of Logger Pro will also install this driver You can find a demo at www vernier com downloads 37 Digital Control Unit User s Manual e Mac Classic OS 9 Make sure the extension LabProUSB is installed on your computer This extension comes with the Vernier Logger Pro 2 or Logger Pro 3 program You can find this installer at www vernier com drivers If you will be using a Serial connection from the LabPro and running LabVIEW 7 you may nee
5. gt lt BEL RED EE EE EA IE VA EL 192 RE N MIE EE MNR N Ed ELKE ee eee 224 mo xX xX x eo a e e e e e DIG Sonic 2 digital Output Control X gt lt x x lt x lt i For example sending a 2001 16 will turn on line 1 of a DCU connected to DIG Sonic 2 If you want to control two DCUs at once you can send out the sum of the two outputs that you would send separately to set them both at once For example sending a 2001 17 will turn on the D1 line of both DCUs Sending 2001 34 will turn on the D2 lines on both DCUs There are two additional commands for directly controlling the digital output lines These commands control only one of the two DIG Sonic ports not interfering with anything going on at the other DIG Sonic port Use the 2011 command to control DIG Sonic 1 without affecting DIG Sonic 2 The same numbers are used for the output as with the 2001 command so Send Out 2001 1 and Send Out 2011 1 are the same except that if some of the digital output lines of Dig Sonic 2 happen to be on the 2001 1 command would turn them off and the 2011 1 command would not change their status Similarly the 2012 command controls just the DIG Sonic 2 digital output lines Send Out 2012 16 Turns on the first line of a DCU connected to DIG Sonic 2 and will not change the status of a DCU on DIG Sonic 1 Note The 2011 and 2012 commands are only available if you are using a LabPro that has had its operating
6. The key ends this program Initialization subprogram for the CBL LabPro and DCU It makes sure that the link between the calculator and CBL LabPro is OK and initializes the unit It also turns off all the DCU lines This program should be called at the beginning of any main program Turns off all digital power lines This subprogram should be called at the end of every main program Turns the output lines specified by D on and off relatively slowly The program continues until a key is pressed Turns on lines specified by D at half power for a T D specified time maximum 120 seconds D digital output pattern must be predefined Turns on lines specified by D at one third power for a specified time maximum 120 seconds 73 Digital Control Unit DCUPWRON subprogram DCUSTEP1 subprogram DCUSTEP2 subprogram DCUWAITD subprogram DCUWAITM subprogram DCUWAITP subprogram DCUWAITV subprogram DCUWHEEL subprogram DCUWHELS subprogram Turns on line D for a time T Forces calculator to wait for CBL 2 Subprogram that directly controls a stepper motor Controls a stepper motor that uses an IC controller Line D1 is pulsed to move a step and line D2 is used to set the direction of movement Waits for a photogate connected to digital channel 2 to become blocked Waits for the motion detector to read an object closer than a specified distance The key e
7. This Express VI tests for a LabPro connected to the computer notes how it is connected the comm Port initializes the LabPro and configures the selected channels If it does not find a LabPro connected to the computer an error dialog box will appear Output all 16 possible states When you want to send a pattern of outputs to the DCU as compared to a single output you set up the pattern using a 1 command The subVI Config Digital Output CH1 vi allows you to easily do this by choosing from a list of possible output patterns The inputs used here are Comm port Ring and Error In There are also inputs for the Operation and List of Values if you choose to create a custom sequence The Error In line is connected to the Error Out line of the previous VI This pattern of connecting the Error Out of one object to the Error In of the next object is a standard practice used in all the VIs in this manual Ring contains a list of the six most popular output patterns you might want to pick e Custom input operation and list values e Flash 3 LEDs e Output all 16 possible states e Run Stepper Motor CCW e Run Stepper Motor CW e Flash each of the 6 of the LEDs in order 41 l Digital Control Unit User s Manua In this program we chose the Output all 16 possible states pattern In other projects you will primarily be choosing to create a custom output pattern For example you may want lines and 2 to alternate
8. 3 or 4 For a motion detector connected to Dig Sonic 1 you use 11 For a motion detector connected to Dig Sonic 2 you use 12 e Operation The third number in the command is usually a 1 This signifies to LabPro that an Auto ID probe is connected Command 3 The third line of our sample program controls the actual data collection Here it specifies taking readings every 0 25 seconds for 50 readings and no triggering is required The syntax for this command is 3 samptime numsamp trigtype trigch trigthres prestore extclock rectime Most of the parameters are not important and you should just leave them off or use zeros Here are the important parameters the ones we have used in our sample program e Samptime the time between samples in seconds The range is 0 0001 to 16000 seconds e Numsamp the number of readings to be made The number of readings can be any integer up to 12 287 Numsamp 1 has a special meaning which will be explained in the next section e Trigtype this specifies if the program should wait for a triggering event before starting the actual data collection 0 means no triggering 1 means wait for the Start Stop button on LabPro CBL 2 to be pressed Other numbers can be used to specify triggering on a certain signal level The default is 1 which you usually do not want so you should almost always put a zero here Leaving this parameter off will often result in a program that does not seem to work pr
9. Lbl A Disp ET Disp ENTER DIRECTION Disp O OR 1 Prompt D Disp NO OF STEPS Prompt N ClrHome prgmDCUSTEP1 Goto A prgmDCUOFF Program DCUSTEP1 Lbl A If D 0 Then 1 31 4 5 9 10 6 L6 Else 1 31 4 6 10 9 5 L6 End Send L6 1 1 14 L6 Send L6 Disp DIRECTION D Disp STEPS N 3 T N 0 L6 Send L6 Get T 1 31 1 0 Le Send L6 3 1 1 01 L6 Send L6 Get T Program DCUMASS prgmDCUINIT 1 1 14 Le6 Send L6 1 31 5 1 2 4 8 0 L6 Send L6 Disp FIRE 75 3 12 5 01 L6 Send L6 Get I prgmDCUOFF Program DCUWARNV prgmDCUINIT ClrHome Disp SET LIMIT Prompt V prgmDCUWAITV Disp LEVEL Disp EXCEEDED Disp OUTPUT 1 ON 1 D 5 gt T prgmDCUPWRON prgmDCUOFF Program DCUALARM prgmDCUINIT Disp ENTER DISTANCE Disp LIMIT Input V ClrHome 10 S Disp WAITING FOR Disp DISTANCE Disp TO BE LESS Disp THAN Disp V T ClrHome Output 1 1 PRESS TO QUIT prgmDCUWAITM If S 0 Then 1 D 10 T ClrHome prgmDCUPWRON End ClrHome prgmDCUOFF Digital Control Unit Program DCUCAR ClrHome 1 T prgmDCUINIT Disp READY FOR ACTION Disp USE ARROWS Disp FOR MOTION Disp PRESS TO Disp QUIT Lbl A 0 D getKey K If K 25 1 D If K 34 2 D If K 2
10. Note that Vout 0 0024 amplitude 0 0012 offset The string command that is created in this subVI is s 401 waveform amplitude offset period The inputs to the VI follow Comm port port number of the open port waveform ring control with all of the possible waveform values amplitude height of the wave The possible values are from 0 to 4095 offset indicates where the wave will be centered The possible values are from 0 to 4095 period indicates how often in milliseconds the waveform will repeat itself The number must be an integer between 5 and 2000 As a result the range of possible frequencies is 0 5 Hz to 200 Hz Pause Pause Located in the Utility subpalette This subVI is used for providing LabPro the required time to finish a command or to hold a command on for a specified amount of time It simply waits the specified number of milliseconds No command is sent to LabPro Stop Collect EN Stop Collect Located in the Stop Close subpalette Use this subVI to stop data collection When collecting in realtime mode you will need to send this command to halt the collection This subVI sends the s 6 0 command to stop sampling phot photo atg hafinel Photogate Config Ch Located in the Photogate subpalette This subVI configures DIG Sonic 1 and or DIG Sonic 2 to be used with the photogate Remember that you must have at least one analog channel activated before sending the Command 3 to start sampling The string
11. Using LabVIEW Create a string of text characters s 3 1 2 0 and wire that string to the input node of a VI that sends commands to the serial or USB port of LabPro Digital Control Unit User s Manual Initialization An important first step of a DCU program for collecting data controlling the digital output lines or controlling the analog output driver is to initialize the LabPro CBL 2 properly The common commands used for this step are as follows Command 7 Ask for status from LabPro Command 0 Reset the LabPro CBL 2 Command 102 Set Power Control In our initialization routines we set the power control for the LabPro CBL 2 to always stay on If this command were not sent the LabPro CBL 2 will power down automatically trying to save batteries and you may get very unexpected results We recommend the use of an initialization routine at the beginning of all your programs It is easiest to use the routines that we have already developed With calculator and REALbasic programs this initialization is usually taken care of with the DCUINIT subprogram or a similar initialization routine In LabVIEW the Init amp ChannelSettup Express VI does the job Programming for Data Collection This section we will concentrate on the commands sent out and not worry about the details of the way the commands are sent We will list our examples in pseudocode which explains what the program is doing but is not the exact characters not the exact
12. power supply The current draw for any one line should not exceed 600mA no matter what Remember that Ohm s law controls the current that flows through the device Current amperes Voltage volts Resistance ohms In some cases you can check the resistance of the device with a meter and calculate how much current it will draw using Ohm s law 55 Digital Control Unit User s Manual Making Additional Cables to Connect Projects to the DCU If you need additional cables you can find the 9 pin sub D sockets at most electronic stores for example part number 276 1538 from Radio Shack will work You would have to solder lead wires to each of the connections you use Even better is to find assembled cables that you can use for example Radio Shack 26 152 can be cut in half to produce two useful cables To identify the lead wires on a cable use a meter which will indicate conductivity The meter allows you to determine which wire on your cable connects to each of the holes on the connector The easiest way to do this is to stick a paper clip in one of the holes on the plug Connect one probe of the meter to this paper clip inserted in a hole in the end of the cable and then touch each of the bare wires with the other probe until you find one that connects meter reads near zero resistance This is even easier if your meter has a setting to make a sound when conductivity is found As you determine the pattern of wires either label the l
13. the 31 tells the LabPro that we want to setup the DIG Sonic channel the 17 tells the LabPro that there are 17 elements in the sequence The numbers that follow are the actual outputs we would like to send The 1 command sets up the pattern The output is started with a 3 command The syntax we use for this 3 command is 3 1 17 0 3 number of seconds between steps number of steps triggering So now we need to see how to send these commands with REALbasic We want to send these commands anytime the Start button is pressed so we put it in the code associated with the Start button Any code that we put here will be executed when this Start button is clicked Outputting information to the LabPro consists of only one command LabPro Write information to be sent out of serial or USB port LabPro is the name of the Serial Communications Control which handles addressing the port to which LabPro is connected The Write part of the command tells the computer that you want to output information to the device 31 Digital Control Unit User s Manual connected to the serial The information in the parentheses is simply what you want to output Even though this code was originally set up for use with a serial port connection to a LabPro it also works with USB connections On Mac OS 9 if you have the proper USB extension on your computer REALbasic sends the data via USB connection to LabPro On Mac OS X if you have the right files in the
14. www mouser com new electronic components but no motors JameCo Electronic Components 1355 Shoreway Road Belmont CA 94002 4100 800 83 1 4242 http www jameco com new electronic parts of all kinds including motors Digi Key 701 Brooks Ave South Thief River Falls MN 56701 0677 800 344 4539 www digikey com new electronic components but no motors Radio Shack stores everywhere 800 843 7422 www radioshack com 69 Appendix Calculator Programs and Subprograms Here is a list of all the calculator programs and subprograms provided on the CD We list calculator variables used by the programs Many programs also use list Le Program Name All Variables Description of For stand alone LabPro CBL2 Notes Used in Program programs a list of Calculator subprograms used Programs DCUALARM V S D T Waits until Motion DCUINIT LabPro only Detector detects an DCUWAITM V object closer than a DCUPWRON D T specified distance DCUOFF Turns on D1 for 10 seconds The key ends this program DCUCAR program DCUCARS Allows you to control a DCUINIT car driven by two DCUWHELS D N stepper motors and a DCUOFF stepper motor IC using the four arrow keys N controls the number of steps taken for each keypress The key ends this program Allows you to control a DCUINIT car driven by two DC DCUWHEEL D T motors using the four DCUOFF arrow keys T controls the time the motor is on for each keypress The key end
15. 5 1 VIs and place new LabPro folder in the user lib directory The Initialization VI states that OS 0 00 This can happen if you are on an international machine and your computer is setup with the decimal separator as a comma Fix this by changing the computer s setting or by changing specific string to decimal and decimal to string functions 53 Digital Control Unit User s Manual Four beeps from LabPro You have sent an illegal command to LabPro or you have sent commands faster than about 30 commands second If there is no delay between sending commands using the WriteString vi LabPro s buffer will overflow or commands will get chopped up and 4 beeps will occur Problems the second time a VI is run If you do not properly stop and close the port you may create any number of problems Do not stop a program with the Stop icon tool in the LabVIEW toolbar An error value of 107367xxxx is returned from the Serial Port Init vi VISA must be installed Also on Linux and Mac platforms a warning is given when running VISA This warning is sent in all cases do to the fact that you are not allowed to change the buffer size in VISA if running on Linux or Mac OS X 54 Digital Control Unit User s Manual Connecting Devices to the DCU For connecting electrical devices use the 9 pin sub D socket on the side of the DCU There are connections for all six digital lines plus power and ground The diagram below shows the connecti
16. Device The device is shown in this diagram as a small lamp but it could be any electrical device that does not have positive and negative leads Connecting More Than One Simple Device If you want to wire a number of simple electrical devices repeat this wiring using additional digital output lines The wire to hole 8 can also be used for ground connections These devices will be turned on when the corresponding digital output D line is on see table in hardware section 56 Digital Control Unit User s Manual Wiring of Several Simple Electrical Devices Notes e Three DC devices can be turned on completely independently and in any combination if they are connected between D1 D2 D3 and ground e Six DC devices could be connected between the six output terminals and ground Four those connected to D1 D2 D3 and D4 can be used in almost any pattern except that you could not have D3 and D4 on at the same time The devices connected to D5 and D6 can be turned on only when all the devices connected to D1 through D4 are off Connecting a Speaker If you connect a small speaker to the DCU you will probably want to put a resistor in series with it so that the speaker is not too loud The resistor should be a power resistor rated at least at 0 5 watts and a fairly low resistance The larger the resistance the quieter the speaker will be When using a speaker you must use a program that turns the power to an output
17. Leads You can wire up to six polarized devices in the same way using connections 1 6 for the positive leads and the G connections for the negative leads Connecting a Bi Color LED Bi color LEDs can be wired so that the current flows either way through them They will produce different colors depending on the direction the current flows If you wire one with a current limiting resistor in series between D1 and D2 you can cause the current to flow either way as follows If you send a 1 to the DCU line D1 will be high and D2 will be low and you will get one color If you send a 2 to the DCU line D2 will be high and D1 will be low and you will get the other color 58 l Digital Control Unit User s Manual Wiring a Bi Color LED Connecting a Motor for Running in Either Direction Simple DC motors can be wired as shown above and they will either be off or on rotating in one particular direction If you want to have the ability to run the motor in either direction you have to wire it as shown below Wiring of a Simple DC Motor to Run Either Direction For a motor wired this way you will get one direction of rotation if D1 is high and D2 is low You will get the opposite rotation if D2 is high and D1 is low It will be off for all other patterns You can connect a second motor wired this way to D3 and D4 and even a third motor connected to D5 and D6 The chart below shows the output patterns of the DCU and the direction of r
18. Manual Here is a second sample program similar to the first but with live data collection Send Out 0 initialize LabPro CBL 2 Send Out 1 1 1 set up channel Send Out 3 1 1 0 start data collection Label A Label this point in the code Get Resulting Data get data Goto A Loop back to A and repeat Eventually some event such as a key press or a click stops this loop and data collection is stopped Send Out 6 0 stop data collection This program is the same as the previous sample through the first two lines after that the data collection portion is different Here is what is going on in the last portion of the program Notice that the 3 command has a 1 for the third parameter as the number of samples The 1 in the 3 command as the number of points causes the LabPro CBL 2 to continuously take data The program then gets the data and loops back to point A in the program to get the next reading This loop continues until the program is interrupted This type of data collection works great for many programs where you just want to monitor some reading from a sensor and display the data continuously a live sensor display or plot a live graph of the sensor reading vs time Calculator programs using Real Time need to have a Get Command to retrieve the data Computer programs can simply check the serial USB buffer to retrieve the data Single Point Data Collection When doing projects involving sensors and output lines you often
19. Then the buzzer goes off and the apparatus is raised out of the way 68 Appendix Sources of Electronic Devices Here are some sources of electronic devices such as lamps LEDs motors buzzers solenoids and stepper motors Vernier Robotics and Control Kit Vernier Software amp Technology sells a Robotics and Control Kit order code RCK DCU It contains connection hardware and assorted components such as motors DC servo and stepper a fan a speaker lamps and holders LEDs and a buzzer for use with the DCU and LabPro analog output lines The parts in this kit were selected to be easy to use with the DCU and LabPro analog output It includes a manual describing 14 projects for student construction programming and experimentation Each project includes feedback and control extensions and other challenges Resources for Teachers Interested in Calculator Controlled Robots Math Machines Fred Thomas and Bob Chaney have recently started a company making equipment to help teachers teach math They make several interesting types of robots laser pointer rotators and other interesting devices Check out http mathmachines net Electronic Component Sources All Electronics 9005 S Vermont Avenue Los Angeles CA 90006 800 826 5432 allcorp allcorop com http www allcorp com good for stepper motors DC motors and new or surplus items of all kinds Mouser Electronics 958 N Main Mansfield TX 76063 4827 800 346 6873 http
20. Webb and Eren Koont of Texas Instruments for their ideas and encouragement on this project David Vernier Vernier Software amp Technology Digital Control Unit User s Manual Introduction The Digital Control Unit DCU is designed to make it easy for you to use the LabPro or Calculator Based Laboratory 2 CBL 2 digital output lines Using the DCU and simple programs you can turn on and off DC motors lamps LEDs buzzers stepper motors and other DC electrical devices You can even develop more elaborate projects such as robots that move around the room or automated scientific apparatus The most exciting projects involve combining the use of sensors connected to the LabPro CBL 2 with output from the DCU Examples include alarm systems temperature controlled environments and smart robots In this new version of the DCU Manual we are also including information on how to control the analog output lines of LabPro The DCU as a Teaching Tool There are several ways you can use your DCU e DCU projects are a great way to teach electronics sensors feedback and control and other engineering concepts The hardware sections of this manual explain how to connect various electrical devices e DCU projects are a great way to teach programming Many programming project ideas are given in this book This manual and the sample programs can provide a good place to start We hope you will take our programs examine them add to them and mak
21. a good way to turn on a fan light bulb or buzzer for example Sending digital output using this method does not stop sampling and it should not affect the analog channels Dig Out Sequence This Express VI lets you control the DCU lines in a sequence This is the way to set a digital output pattern for running a stepper motor turning a servo motor flashing lines on and off and many other operations The next set of VIs that are discussed can be found in the nine subpalettes circled Moving down the palette we will now look at some of the VIs found in the next nine subpalettes Not all of the VIs are summarized but it should give an idea of what is available Configure_Digital Output CH1 Located in the Configure Channel subpalette There is a separate VI for configuring CH2 This subVI is used to set the output value on DIG Sonic 1 to a series of output states LabPro outputs one element for each sample This command is used for sequential digital outputs used for turning a stepper motor flashing all of the LEDs or turning a servomotor for example Several common output states are pre programmed in this subVI and can be selected from the Ring control In addition this subVI allows you to create your own custom sequence by selecting the custom option from the ring control and then sending a string value to represent the operation and list of values The string command that is created in this subVI is s 1 31 operation list
22. can control the A amplitude V analog output line of B amplitude in the LabPro and the units of 0 0024 V function generator Use S offset this program if you want to examine the code to see how to control analog output FUNCTGEN This program is a fairly DCUINIT LabPro only complete function DCUOFF generator program Use to set a DC voltage output or set up a output waveform to test hardware connected to the analog output line of LabPro 72 Digital Control Unit Appendix B Here is a list of all the subprograms provided on the disks Subprogram Name DCUBUZZ subprogram DCUCHKD subprogram DCUCHKP subprogram DCUINIT subprogram DCUOFF subprogram DCUPULSK subprogram DCUPWR2 subprogram DCUPWR3 subprogram All Variables Used in Calculator Programs F P T N I Variables that LabPro CBL2 Notes must be set Description of Program Produces an on off signal F Frequency and On CBL 2 or LabPro on digital out line 1 for a T Time must be the limit is 12 000 specified time and at a predefined Also F steps specified frequency For T must be lt use with speakers and 512 simple buzzers Checks and reports the LabPro Only status of a photogate connected to digital channel 2 Blocked or Unblocked The key ends this program Checks and reports the status of a photogate connected to the CH1 analog input Blocked or Unblocked
23. command that is created in this subVI is s 12 4x 10 The inputs to the VI follow Comm port port number of the active port ms to wait after pause following the write to LabPro Photogate channel ring control that allows you to pick which channel s to configure of of paints points Chi Chd2 Photogate_NumPts_Ch41 Located in the Photogate subpalette There are subVIs for DIG Sonic 1 and DIG Sonic 2 This subVI is used to get the number of transitions recorded by a photogate connected to DIG Sonic Channel 1 Use this subVI in a realtime data collection loop for tracking the number of transitions in realtime This subVI reads all 52 l Digital Control Unit User s Manual of LabPro s data and parses out the transitions recorded The string command that is created in this subVI is s 12 4x 0 The inputs to the VI follow Comm port port number of the active port ms to wait after amount of pause between writing the command and reading the data bytes to read the number of bytes to read 19 bytes for the photogate data O x This subpalette contains our low level driver VIs The last subpalette discussed contains the low level LabPro Driver VIs We will not go into detail about these different VIs and what their function is Use these VIs to create commands that do not exist in the LabPro palette to create your own custom subVIs or to sends commands directly to LabPro Even if you do not use these VIs you should
24. for the pattern so we want to add the line LabPro Write s 2001 3 chr 10 To get the program to hold here for 3 seconds we need a REALbasic Sleep statement Sleep 3000 wait 3 seconds This will have the program wait at this point for 3 seconds Note that the REALbasic Sleep commands use milliseconds for the time Buzz a speaker at 50 Hz for 5 seconds For the final change we need to make the speaker buzz Code we have included in the REALbasic methods will make this pretty easy All the sample REALbasic programs on the CD include a number of subroutines stored in methods for you to use One of them is named DCUBUZZ and it does exactly what we would like here If you look down this list at the left side of the window you shall see a heading labeled Methods Click on this entry to expand it Once it expands you shall see many entries in the left side of the window This is a list of the methods that we have written to aid you in developing your applications We can add this method to our code The DCUBUZZ method requires two parameters the frequency of the buzz in Hz and the duration of the buzz in seconds Here is what the DCU Start button code will look like after adding in the appropriate DCUBUZZ command and the other changes have been made Sub Action LabPro Write s 2001 3 chr 10 turn on DCU lines 1 and 2 Sleep 3000 wait 3 seconds REALbasic Sleep commands use milliseconds for time DCUBUZZ 50 5 32 Digi
25. get maximum amplitude of vibration at the antinodes We usually get a movement of more than a centimeter at the antinodes After you get a good pattern go back to the fundamental frequency You can calculate what it is Next try other frequencies Sometimes we can get up to the 5 and 6th harmonics displayed pretty well Drive a mass on a spring to explore resonance Use a small speaker with a paper clip glued to it Mount the speaker with the cone pointed downward Hang a light weight flexible spring from the paper clip and then hang a small mass from the spring Let the mass oscillate up and down naturally and estimate the natural frequency Now use the analog output line of LabPro to drive the speaker with a sine waveform Try to find the resonance frequency Note the response at frequencies close to the natural frequency resonance Build an Audio Voltmeter Connect the analog output line to the speaker Write a program to read a voltage probe or really any analog probe connected to CH1 Set up a 4 volt sine wave analog output and have the program adjust the frequency depending on the sensor reading The result is a system which responds with frequency changes as a 64 Digital Control Unit User s Manual sensor is used This is a great tool for blind students and also can be helpful in troubleshooting intermittent sensors and circuits The human ear is amazingly good at hearing changes in frequency Power a Bi Color LED Connect the anal
26. hardware for your future projects that you connect to the DCU 28 Digital Control Unit User s Manual Note that the Start button does nothing in this program It is there to maintain consistency with our other programs When you are finished experimenting with the DCUTOGGL program click on the Stop button to terminate communication with the LabPro and then quit the program REALbasic will still be running Opening the DCUCOUNT Program Choose Open from the REALbasic File menu and navigate to the DCU sample programs folder Within that folder is a file DCUCOUNT Open this file Answer no to the question about saving changes to the last program When the file opens near the center of the screen you will see a Window called the Project Window that lists the various other windows that make up the program It has an entry MAIN Double click on this entry An Overview of REALbasic REALbasic uses a lot of windows to display information The program is built around a main window to which you add buttons labels text boxes list boxes and controls Many of the objects on this window have REALbasic code instructions for what the computer should do associated with them For example pressing a button will result in the code attached to the button action being executed This is why REALbasic is referred to as an Event Driven language Pressing a button is considered an Event The Windows used by REALbasic C File Edit Format Debu
27. most of this manual discusses using special programs or home made programs for controlling the Digital Control Unit you can also use the DCU with the Vernier Logger Pro program Versions of Logger Pro from 3 3 and newer can control the DCU Connect the DCU and an analog sensor to your LabPro and start up the Logger Pro program Choose Set Up Sensors from the Experiment menu Click on the DCU icon showing it connected to the LabPro A pull down menu should appear One item on that menu is Digital Output Choose it A dialog box will appear which lets you select a sensor or any other column of data and set a limit You can choose to have the DCU turn on any lines you specify when the value goes above or below the limit Similarly you can control the analog output line of LabPro in Logger Pro 3 Connect the LabPro voltage probe to CH4 Start up Logger Pro and choose Set Up Sensors from the Experiment menu Click on the voltage probe icon showing it connected to the LabPro A pull down menu should appear One item on that menu is Analog Output Choose it A dialog box will appear which lets you set the waveform amplitude and frequency of the analog output This output will continue even after you close the dialog box You can take data as the analog output continues in fact it is easy to plot the voltage output from CH4 as it is changes Digital Control Unit User s Manual DCU Overview The Digital Control Unit DCU is a small box with a sh
28. motion whenever it starts to move off the line e Mount a motion detector on the robot and write a program that has the robot move just up to an object and then stop Sun Seeker Another interesting project using feedback is to build a light seeker Mount two light sensors so that they point in slightly different directions on an apparatus that can be rotated Write a program that compares the light level detected by the two light sensors and then rotate the apparatus toward the one which detects the most light If this pattern continues the light seeker should always end up pointed at the brightest light source This is the basic concept used on some solar panels to track the sun 67 Digital Control Unit User s Manual Tea Maker We have made a stepper motor driven automatic tea maker The device consists of a tea bag a temperature probe and a conductivity probe mounted so that the stepper motor can raise or lower them into a tea cup The program starts by lowering everything into a cup of hot water The stepper motor gently raises and lowers the tea bag to help with the infusing At the same time the program is monitoring the conductivity which increases as the tea dissolves When the conductivity reaches a set limit the apparatus is raised such that the tea bag is pulled out of the water but the temperature probe is still in the tea The temperature is then monitored until it drops to a previously specified perfect drinking temperature
29. of the While loops if it is pressed The relevant code is SubRoutineStopButtonClicked false While SubRoutineStopButtonClicked false start loop main code of loop if keyboard asynckeyDown amp h31 then SubRoutineStopButtonClicked true wend This tests the keyboard during the loop to see if the Space Bar key label amp h31 has been depressed If it has been the variable SubRoutineStopButtonClicked is set to true and the While loop end This same idea needs to be used in programs similar to DCUWARNYV which include loops If you do not handle this properly you can get into a situation were the REALbasic program is running and there is no way to stop it Getting Data Back from LabPro In REALbasic programs that ask LabPro to return data or other information there are two ways to handle the data 34 Digital Control Unit User s Manual Normally whenever data are available on the serial or USB port of the computer the Data Available subroutine listed under the serial control LabPro would automatically takes over and processes the data We have written programs to operate that way and it works fine In the sample programs we provide on the CD we have chosen to handle things differently We do not allow the Data Available subroutine to take control and instead use code like this in the main part of the program Dim Buffer as String A string that will be used for reading values from LabPro Dim CurrentValue as Dou
30. rule e Bipolar stepper motors have 4 lead wires e Unipolar stepper motors have more than 4 wires usually 5 6 or 8 60 l Digital Control Unit User s Manual No matter what type of stepper motor you have remember that it needs to match the voltage you are using on your DCU power supply If you are using the LabPro CBL 2 power supply you should use 6 volt stepper motors Identifying the leads on a stepper motor can be tricky It helps if you have a diagram provided by the manufacturer Unfortunately you are often using a surplus stepper motor and need to figure it out yourself First determine which type of stepper motor it is Next look for patterns Examine the wires carefully Refer to the diagrams below which symbolically show how the two types of stepper motors are wired inside Use a meter to measure resistance Remember that a coil will have a few ohms of resistance Use a little trial and error and you will be able to get it going If you use the stepper motor which comes with the Vernier Robotics amp Control kit RCK DCU the leads are identified in the documentation which comes with it Bipolar Stepper Motors To connect a bipolar stepper motor directly to the DCU wire it as shown here Direct Connection of a Bipolar Stepper Motor Wired this way you can control the bipolar stepper motor using the DCUSTEP You can also use the DCUSTEP3 program which is an improved more complicated program for controlling ste
31. some better ideas of your own e Turn on and off DC motors and operate them in either of two directions e Control stepper motors or servo motors e Create temperature controlled environments e Add a buzzer to the LabPro CBL 2 to warn you when an event occurs such as a person walking near a motion detector e Make live traps for small animals or bugs activated by a sensor detecting the presence of the animal e Create an automatic tea brewer e Make automated scientific instruments and demonstration equipment e Control flashing lamps and LEDs and moving objects for marketing displays Digital Control Unit User s Manual e Build kinetic sculptures e Build an automated battery tester e Build a roving robot with sensors controlled by a calculator or a laptop computer Vernier Robotics and Control Kit Vernier Software amp Technology also sells a Robotics and Control Kit order code RCK DCU It contains connection hardware and assorted components such as motors DC servo and stepper a fan a speaker lamps and holders LEDs and a buzzer for use with the DCU and LabPro analog output lines The parts in this kit were selected to be easy to use with the DCU and LabPro analog output It includes a manual describing 14 projects for student construction programming and experimentation Each project includes feedback and control extensions and other challenges Using the DCU and the LabPro Analog Output Line with Logger Pro Even though
32. stop the sampling and it should not affect the analog channels This subVI is used for such things as turning on a light bulb or turning a DC motor In most cases just a single data value is used e g s 2001 1 although there is an option of sending more than one Note that the input for the data value into this subVI is a string not a numeric String commands are sent to LabPro and in this case the input to the subVI is simply a part of the 2001 command string The string command that is created in this subVI is s 2001 datal data2 data3 dataN The inputs to the VI follow 51 l Digital Control Unit User s Manua Comm port port number of the open port datal data2 dataN Data values must be between 0 15 For values outside this range behavior is undefined Action Action_Analog Output Located in the Action subpalette This subVI sets parameters to control the analog output driver in LabPro The analog output is present on line 1 of CH4 Therefore the voltage clips supplied with LabPro may be used to connect the analog output to external circuits Once the channel has been configured the output is enabled immediately regardless of data collection mode and will remain active until the unit is reset or until it is disabled Waveforms other than DC values are divided into steps of discrete values Since this analog out shares the CH4 Vin pin you may monitor the output voltage by configuring CH4 to read the analog input
33. that the program is finished but the LabPro CBL 2 and DCU are still doing something with the digital output lines This is because the LabPro CBL 2 got its command to do the sequence of outputs and they are continuing even though the calculator went on executing the rest of the program A slightly different situation happens when you send commands to the LabPro CBL 2 to have the DCU do something else before the first operations sent are completed Consider this program for example prgmDCUINIT Initialize the LabPro CBL 2 1 31 2 0 1 LS6 Set up digital output to turn on and off the first three lines Send L6 3 1 10 0 L6 Go through 10 steps taking 1 second for each step Send L6 2001 0 L6 Turn off power to all lines Send L6 If you try this program it will not operate the way you might expect If the DCU is connected you might expect to see the first three red LEDs flash on and off for ten seconds and then the power should go off Instead the LEDs will briefly flash but the program quickly ends with the power turned off Why The problem is that the LabPro CBL 2 starts executing the sequence of 10 steps but then is sent a new command telling it to turn the power off It interrupts what it was working on and follows the new instruction There is a solution to these problems The trick is to have the LabPro CBL 2 do a probably unnecessary sensor reading at the same time Then you can use a GET calculator program stat
34. the DCU trip the camera shutter when an animal is detected by either a photogate or a Motion Detector 66 Digital Control Unit User s Manual Stepper Motor Projects Stepper motors are great for projects You can control the exact position of the rotating part of the motor There are many surplus stepper motors around left over from disk drives and similar devices Some stepper motors have as few as 48 steps in a complete rotation Many come with built in gear systems to provide hundreds or even thousands of steps per rotation This also increases the torque of the motor Servo Motor Projects Servo motors have a lot of torque so they allow you to do things that require short motion with a lot of force We have used them to lift the end of a dynamics track to start a cart rolling to launch rubber bands and to simulate an assembly line sorting system A DCU Controlled Robot Using DC Motors One popular project is to build a robot with two wheels controlled by the DCU A third wheel rotates freely to allow the robot to turn You can have all of the following motions e Forward Both motors moving forward e Backward Both motors moving backward e Turn Right Left motor rotating forward right motor rotating backward e Turn Left Right motor rotating forward left motor rotating backward The DCU was partly designed around this project There are output patterns for all of these motions using the D1 D2 D3 and D4 lines This allow
35. time to occur Block Diagram of DCUCOUNT vi You will see that this program is made up of two Express VIs three subVIs and some Numeric functions The execution order of this program is left to right but this is not controlled by the position of the VIs on the block diagram LabVIEW uses data flow programming meaning that a sub or Express VI will not execute until all of its input data are available Notice that the blue data wire originating from the Error Out node of the Init amp ChannelSetup Express VI is connected through all of the sub and Express VIs This forces the program to flow from left to right All of the VIs in this example are provided in the LabPro folder from the CD placed by you in the user lib folder of LabVIEW On the next page is an explanation of what each of the five main parts of DCUCOUNT does 40 Digital Control Unit User s Manua ol OPEN Init amp ChannelSet up 2 Source vi Comm pork Error Out gt LabPro Connectecr ADPro OS gt Active channel art The Express VI Init amp ChannelSetup_2 begins the program Express VIs are a new feature of LabVIEW 7 They contain and hide a lot of low level code Express VIs can be configured with a dialog box that appears when you double click the Express VI double click on it to see the configuration dialog box Alternatively they can be configured by wiring data into their input nodes during program execution just like a subVI
36. to loop until the total number of steps are completed These two approaches are explained with more detail in the next two sections Controlling the Digital Output Lines Direct Control After you initialize the LabPro CBL 2 if all you want to do is to set the status of the lines turn something on or off you can use a 2001 command Send a command with this format Send Out 2001 D Where D is the output pattern from the table above that you want to set and hold Remember that in LabVIEW and REALbasic commands and parameters must be formatted as strings Example 1 Turn on digital output line D3 and leave it on until you send another command to turn it off Send Out 2001 4 If you do not understand why a 4 is used as the output pattern study the chart just above Example 2 Turn off all the digital lines Send Out 2001 0 14 Digital Control Unit User s Manual Controlling the Digital Output Lines Sequence Control Producing a series of digital output patterns is very useful in a number of situations including flashing lamps running stepper or servo motors or making a speaker vibrate to make sound On the other hand this kind of control is a little more complicated Programming to control the digital out lines in this manner is similar to programming for collecting data The important steps are 1 Initialize the LabPro CBL 2 2 Use a Command to set up the digital output channel 31 for a sequence of
37. tube mass driver A very simple program much like DCUCOUNT DCUSERVO Controls a servo motor connected to D1 This program works for many servo motors including the one in the Vernier Robotic amp Control kit DCUSTEP Simple program that allows user to specify direction and number of steps for a directly connected stepper motor unipolar or bipolar This is a simple easy to understand stepper motor program DCUSTEP3 Improved program that directly controls a stepper motor This version is best to use if you plan to use the stepper motor for several different motions one after the other It keeps track of the stepper motor position as it moves This program is more complicated than DCUSTEP because it keeps track of the stepper motor positions DCUSUN This program assumes that you have two auto ID Vernier light sensors connected to CH1 and CH2 and a DC motor connected to the D1 and D2 output lines of the DCU If the two light sensors are mounted pointing a few degrees apart and so they can be rotated by the motor the program will turn the motor in the direction of the brightest light so the light sensors follow a light source DCUTEMPC Program for creating a temperature controlled environment It turns on a heater D1 if temperature is below minimum temperature and turns on a fan D2 if temperature is above maximum value This is common feedback and control type program It will work with any AutoID probe in CH1 DCUTOGGL Program t
38. 000 ms This means that you have very good resolution for frequency control at low frequencies but not very good resolution at higher frequencies For example the very highest frequency is 200 Hz followed by 166 Hz 143 Hz 125 Hz etc On the low frequency end the lowest frequency is 0 5 Hz and there are 1000 steps to 1 Hz In the mid range at 10 Hz the steps are about 0 1 Hz DCU Project Ideas The exciting thing about the Digital Control Unit is the projects you can build using it for control Here are some projects ideas with a few tips and suggestions Most of these projects can be done with the Vernier Robotics amp Control Kit RCK DCU Flashing Lamps and LEDs You can use almost any lamp that has a voltage rating to match the DCU power supply you are using Many different types are available from electronic supply houses including Radio Shack Lamps are almost always non polarized so they do not have to be oriented in one particular way LEDs Light Emitting Diodes are very inexpensive and last almost forever LEDs are polarized so they must have their positive and negative leads oriented properly Normally the longer lead of an LED is positive Also the negative lead is usually marked with a flattened side on the LED In most cases you should connect a current limiting resistor in series with the LED This will limit the amount of current that flows through the LED Without this resistor the LED may quickly burn out Ther
39. 4 3 D If K 26 4 D If K 95 Goto Z If D 0 Goto A prgomDCUWHEEL Goto A LD1 Z prgmDCUOFF Program DCUWAITM 1 12 2 gt L6 Send L6 6 S Send L6 Output Output Output Output 1 6 WAITING FOR DISTANCE TO BE LESS r r THAN Ww V L6 2 3 4 5 Output 5 ta Las Send L aL 1 1 1 6 70 76 Appendix C While S gt V Get S Output 7 1 S getKey K If K 95 End Program DCUWHEEL 1 1 14 L6 Send L6 Disp DIRECTION If D 1 Then Disp FORWARD 1 31 2 5 01 LS6 Goto A End If D 2 Then Disp BACKWARD 1 31 2 10 0 Le Goto A End If D 3 Then Disp LEFT 1731527670 L6 Goto A End If D 4 Then Disp RIGHT 1 31 2 9 01 LS6 Lbl A Send L6 Disp T Disp SECONDS 3 7 2 01 L6 Send L6 Get T
40. D The LabPro Palette is Located in the User Libraries Palette Express VIs and subVIs The LabPro folder contains Express VIs and also subVIs Express VIs were introduced in LabVIEW 7 0 to provide an interactive means of configuring the inputs Express VIs allow you to double click on them to bring up a dialog box providing you with an easy method for configuring your program As you know a standard subVI is configured by the values that are wired into the subVIs connector nodes An Express VI can also be configured in this manner This means Express VIs can be configured in two ways wiring in a value or inputting a value in the Express VT s dialog box If configuration values are wired they will take precedent over values that are input into the Express VI s dialog box In most cases Express VIs will be configured in both ways with the more important inputs configured in the dialog box and the less important inputs wired into the nodes With our Express VIs you will always be required to wire in Comm Port and the Error In at a minimum The LabPro Express VIs were created by us using a special toolkit from National Instruments you will not be able to create your own Express VIs without having this toolkit installed We have created a selection of Express VIs that perform most of the major functions of the LabPro It is possible to view the subVIs that were used to create the Express VIs by right clicking open apple or command clicking on a
41. D flashes there must be some code associated with that button that sends out the correct sequence to the DCU Let s take a look at this code With the DCUCOUNT user interface window open on the screen but not running double click on the Start button This will bring up a new screen that we haven t seen before This is the Code Editor where the code is displayed and edited By double clicking on the Start button the code view has opened with the cursor placed in the section of code that is associated with the clicking of the Start button 30 Digital Control Unit User s Manual File Edit Format Debug Window Help DCUCOUNT Code Editor DCUCOUNT EIE v BA Controls Sub Action G DCUTEMPLATEStart LabPro write s 1 31 17 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 0 chr 10 a LabPro write s 3 1 17 0 chr 10 takes said steps AN End Sub Q MouseMove Q MouseEnter Q MouseExit Q Open Q Close Q DropObject DCUTEMPLATEstop El InputFromLabPro B Label2 5 LabPro SubLabel b Events D Ee Menu Handlers b Methods b G Properties View of the code that is associated with the Start button Let s look at exactly what we have here On the left side of this window you should see a hierarchical listing of entries The item at the top of this list is Controls This item is opened in the hierarchical view and we see several sub items in this li
42. Diagram File Edit Operate Tools Browse Window Help dy E om a bol or 13pt Application Font odmi e ol OPEN Init amp ChannelSet up_2 Source vi Comm port Error Out Eae LabPro Connectecr ere D O StopResetClose_ Active channel art 3 Comm port 1000 1000 00 By gt Error In Use the 1 command to configure a sequence of digital outputs to DigSonic 1 Sending the 3 command starts the sampling In this example there will be 16 outputs each lasting 1 second The pause is required to give the outputs enought time to occur Modified Block Diagram of DCUCOUNT vi Now add this code to your program and try running it again Watch the DCU LEDs You should see the Ist and 2 DCU LEDs go on for three seconds and then the LEDs cycle through the 16 outputs more slowly than before Exit LabVIEW or open another DCU sample program if you like You may or may not want to save the changes you made You also can save your changed version of the program with a different name This is an example of how you can use the raw material we provide in the window of LabVIEW code to create your own DCU control programs LabVIEW is an extremely powerful programming tool and we have provided a lot of VIs for controlling LabPro for data collection and analog and digital output To learn how to properly use these VIs in your programs refer to the next section of this manual Additional Notes on LabVIEW P
43. Digital Control Unit DCU Manual Vernier Software amp Technology 13979 SW Millikan Way Beaverton Oregon 97005 2886 503 277 2299 888 837 6437 FAX 503 277 2440 www vernier com info vernier com Monday April 25 2005 Order Code DCU BTD Contents INTRODUCTION ree see ee Dei ene EE es tne cubs Give dea SEER ge ee acd DS Ind Rosi eN Maen dees SES 1 DCU OVERVIEW EER EE OR EER EE BGS hese ned OR EO RE HE OE EE EEN 3 ANALOG OUTPUT OVERVIEW ee SERE Ee Ge EE ABA EEO DE Ge A Ge eg GE RE i te ee 5 THE DEU SAMPLE PROGRAMS CD sienn aise ee Se bee Vee Ge Ee bb eg ee ee Ras Seed geb ee oe We ese Deeg se 5 PROGRAMMING OVERVIE Wise se sesde nes ie Eise P ED gees Se Re DER s a ie Ee EER Ee AD DEER SEEN SE Ke Oe BEER stab as ige Ee es Ee ER De ee EDGE RE os PaT SiS 9 PROGRAMMING FOR DATA COLLECTION iedere eers skede sd ese dope od gede seg deeg Se ee eg ede ee Seed eb ees eg de gee 10 PROGRAMMING FOR THE DEU siese es sca een Siok EE se seis ee eh E Ge lute oe es OTEN Wee DEOS TEAS TE EE E ee Se bib dee ef 14 PROGRAMMING FOR ANALOG OUTPUT CONTROL ee se see see ee ee ee Gee Gee Ge ee ee Ge ee ee ee ee Se Se ke ee Re ee 17 USING THE DEU WITHA CALCULATOR ie ees eet set se REED Ge SAGE BEG Re Ee SR Ge ERG eye Bees Re eke ks Ee Gee See BEKEER GEE EE SEE ER Eee rS SEE 19 ADDITIONAL NOTES ON CALCULATOR PROGRAMMING ees see sees se ee se es se ee se se ee se ee ee ee Ge Se Ge Re Ge Re ee ee 21 USING THE DCU WITH REALBASIC AND A MACINTOSH COMPUTER ese see
44. File Edit Format Debug Window Help E DCUTOGGLE E Menu CO BlankwaitTemp B CommError Initial REALbasic Screen Let s try running this program Select the Run command from the Debug menu at the top of the screen This will bring up another window You should see the user interface for the DCUTOGGL program which includes Start and Stop buttons and buttons for controlling the six output lines of the DCU The words LabPro Found should appear in the ListBox at the bottom of the screen if all your hardware is connected properly You will get an error message if there is a problem with the hardware If this happens check the power to the LabPro and the connection to the computer If that does not help try removing the power from the LabPro and then plugging it back in DCUTOGGLE Allows direct control of the LabPro found on LabPro USB DCUTOGGL Program User Interface The six buttons on the screen correspond to the DCU lines 1 6 This program will allow you to turn these lines on and off Try clicking the mouse on the 1 button on the screen The red LED labeled 1 should go on Press the 1 button again and it should go off Try to turn the other LEDs on and off using the 2 through 6 buttons on the screen Note that there are some combinations of LEDs that are not allowed so that in some cases when you turn on an LED some others may go off The DCUTOGGL program is very useful in testing
45. G Sonic 1 and then click on the Run button This will start the VI running The program begins executing the code on the Block Diagram that sends the output sequence to the LabPro It sends each of the 17 outputs sequentially holding each output for 1 second Wait for all 17 outputs to cycle through and press the Run button again The sequence should start over again Examining the LabVIEW Code Clicking on the Run button began the code that told the LabPro to send a sequence of LED flashes So now let s take a look at this code found in the Block Diagram remember an easy way to toggle between the Front Panel and Block Diagram displays on screen is to press the Control E keys Windows Alt E keys Linux or Open Apple E keys Macintosh DCUCOUNT vi Block Diagram aid File Edit Operate Tools Browse Window Help ole Olt Y kale os 13t Application Fot F 5 tax eed ol OPEN Init amp ChannelSet Ring 1 0 up_2 Source vi Output all 16 possible states Comm port gt Numpoints 1 For RT mode Error Out gt 17 LabPro Connectec calle al StopResetClose_ Active channel arr m gt Comm port l Error In Use the 1 command to configure a sequence of digital outputs to DigSonic 1 Sending the 3 command starts the sampling In this example there will be 16 outputs each lasting 1 second The pause is required to give the loutputs enought
46. I uses three Express VIs to communicate with LabPro We will discuss these VIs later in this manual BR File Edit Operate Tools Browse Window Help DEU gt Olt 13pt Application Font x For Tr a toggle a his example a shift register is used to determine if the DCU input has changed EI it has othing is done if it has the new input is sent to the Express VI to EE Block Diagram of DCUTOGGL vi Opening the DCUCOUNT Program Choose Open from the LabVIEW File menu and open the DCUCOUNT vi If asked answer no to the question about saving changes to the last program We will take a look at this simple VI as a way of learning how LabPro is controlled by LabVIEW Running the DCUCOUNT Program DCUCOUNT vi is a program that we created to count through the 16 possible DCU outputs Each of the numbers 0 15 represents one of the 16 outputs to the DCU Therefore a program that goes through each of the 16 outputs on 39 Digital Control Unit User s Manual the DCU would be a program that sends the numbers 0 15 to the LabPro for use by the DCU It sends out a zero at the end to make sure all the lines are off for a total of 17 steps in the pattern Let s try running this program Make sure your DCU is connected to DI
47. LEDs The numbers 12 to 15 control the status of the last two lines To give you an introduction to what DCU programs are like the DCUCOUNT program code is listed below This is TI 83 code but the code for other calculators is similar There are a number of things to notice about this short program prgmDCUINIT Calls a subprogram named DCUINIT This subprogram initializes the LabPro CBL 2 Disp COUNTING Displays message on calculator screen 19 Digital Control Unit User s Manual 1 31 17 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 0 L6 This line sets up a list which will be used as a 1 command to set up the DIG Sonic 1 digital output channel of LabPro Send L6 Sends this list to the CBL 2 LabPro 3 117 01 L6 Sets up a list starting with a 3 followed by some other numbers This command will control the output from the LabPro CBL 2 Send L6 Sends this list to the LabPro CBL 2 When we ran this program we saw that the DCU went through a series of steps with the output pattern changing How is that accomplished The 1 command sets up a sequence of outputs with 17 patterns The 17 numbers that follow are the patterns The 3 command tells the LabPro to step through each pattern taking 1 second per pattern It s now time to customize the DCUCOUNT program We will make three changes The first one is to make the program step through the patterns more slowly Examine the program code on the calculator screen The details of doing
48. Mac on the Express VI and choosing Open Front Panel The sample DCU programs do not use all of our Express VIs You may want to take the time to look at the rest of these by going to the LabPro palette in the User Libraries function palette In fact in most examples we have chosen not to use our Express VIs in order to keep the commands more transparent If you are looking over our examples do not be confused when you see a section of code consisting of a handful of subVIs that could be replaced by one of our Express VIs we wanted you to see more of the details 46 l Digital Control Unit User s Manua File Edit Operate Tools Browse Window Help mi Smaal gt Untitled 1 Block Diagram loj x Init amp ChannelSet up_2 Source vi Dig Out Direct_2 Source vi LabPro Connectecr StopResetClose Error In Comm port Active channel art Error In Es ae SS SS ee Example Program using LabPro Express VIs to turn on lines D1 and D2 for 5 seconds Low Level VIs and High Level VIs The LabPro collection of VIs includes both low level and high level VIs The low level VIs provide easy transparent access to the LabPro command and communication code The high level VIs hide the LabPro command strings and the communication code We have provided high level VIs such as the Express VIs to allow users to create data acquisition and control programs without having to learn the low level details such as the LabPro comma
49. Programming for the DCU section of this manual Digital Output Sequence For a good example of performing a digital output sequence open and study the program DCUMASS In this program a custom sequence of 5 outputs is sent 1 2 4 8 0 Run the program you will see the DCU s LEDs flash 4 times the fifth output is a zero so the LEDs will be turned off for this last output Now go to the block diagram and change the Numpoints constant It is currently 5 change it to 10 Run the program and note that the sequence performs 10 outputs 1 2 4 8 0 1 2 4 8 0 Try Numpoints of 12 now the sequence will be 1 2 4 8 0 1 2 4 8 0 1 2 Now change the Samptime front panel control from 0 12 to 1 0 Notice how the 12 outputs are slowed down each one lasting for 1 second Now go to the block diagram and change the sequence from 1 2 4 8 0 to 1 2 This new sequence has 2 elements and therefore the Operation constant must be changed from 5 to 2 Run the program If you have left the Numpoints equal to 12 the output pattern will be 1 2 1 2 1 2 1 2 1 2 1 2 each output lasting 1 second For more information on sequence control see the Programming for the DCU section of this manual Using the LabPro subVls and Express VIs Programming to control the LabPro using LabVIEW is very different than programming in other languages for two reasons LabVIEW s graphical interface makes things easier and Vernier has provided more complete higher level code to sup
50. al This manual describes the Digital Control Unit DCU and how it can be used with the Vernier LabPro and the CBL 2 from Texas Instruments It also goes into details of how to control LabPro s analog output line Details on how the DCU and analog output work how to control the outputs and how to connect devices to them are all covered in the manual Use this manual to learn the programming techniques that allow you to control the DCU and the analog output line with TI graphing calculators LabVIEW and REALbasic In addition the CD that comes with this manual contains many sample programs for performing digital and analog output with any of these programming languages using an array of electronic devices Some of these programs show how to combine output with reading data from a sensor This manual focuses on programming the LabPro to control the DCU and analog output line It does not cover all of the commands that control the LabPro For more information on this refer to the LabPro Technical Reference Manual The LabPro manual is available free on our web site www vernier com diy for Do It Yourself Also you will need to refer to the manuals that came with your calculator or your LabVIEW or REALbasic documentation for programming information If you are using a CBL 2 you may want to refer to Getting Started with the CBL 2 which is included with every CBL 2 If you are using a calculator for DCU programs this manual also assume
51. at these waveforms are created using a look up table of sines stored in the LabPro All other waveforms are created by simple calculations done by the LabPro microprocessor Only a few different amplitudes are possible and the amplitude and offset parameters have different meanings than with other waveforms For sinewaves centered at zero your only choices for amplitude are 4 Volt Sine Waveform 8 volts peak to peak 401 6 0 3072 T where T is period in milliseconds 2 Volt Sine Waveform 4 volts peak to peak 401 6 1 1536 T where T is period in milliseconds 1 Volt Sine Waveform 2 volts peak to peak 401 6 2 768 T where T is period in milliseconds If you want to experiment with waveforms other than the ones described above such as ramp triangle and square waveforms that include negative voltages try changing the offset value The general equation for voltage control is Vou 2 4mV amplitude 1 2mV offset Here are some examples of possible waveforms For a 100 Hz ramp up waveform 5 volts peak to peak centered at zero use 401 2 2083 2083 10 For a 50 Hz ramp down waveform 2 volts peak to peak centered at 1 V use 401 3 792 1667 20 For a square waveform 4 volts peak to peak centered at zero use 401 5 1667 1667 T T is period in ms Analog Output Programming Challenges e Write a program to set up a 2 Hz triangle waveform with an amplitude of 3 volts e Write a program to produce a 4 volt sine wave with a frequenc
52. ation Data Collection Programming Challenges e Write a program to read the temperature with an auto ID temperature probe every second for 30 seconds and then display all the temperatures e Write a program to read and display the temperature read by an auto ID temperature probe every second until the user stops the program e Write a program to read and display the temperature read by a non auto ID temperature probe called a Direct Connect Temperature Probe This type of probe produces a voltage output of 0 volts at 17 8 degrees C and the voltage output increases by one volt for every 55 56 degrees C 13 Digital Control Unit User s Manual Programming for the DCU The most important piece of information when programming the DCU is the table that lists the 16 possible output patterns This table was first introduced in the DCU Overview section Here it is again 1011 Ne se a Ne The numbers in the Output column of this table are frequently used when sending commands to the LabPro CBL 2 The number that is sent will determine what line or lines are turned on and off There are two basic approaches when performing digital output One is to command the LabPro CBL 2 to turn on a line or lines and hold those lines on until told otherwise The other is to command the LabPro CBL 2 to perform a sequence of outputs so that at a specific interval a new line or lines is turned on This sequence of outputs will continue
53. be aware that they exist and that if you dig deep into the high level VIs you will always find these VIs doing the communication work LabVIEW Troubleshooting Help Problems with communication over the serial port NI VISA drivers were not installed This driver is a National Instruments driver found on the second installation CD labeled Device Driver Reference CD If you are using the LabVIEW Student Edition this version does not contain the driver sets This driver needs to be installed or it can be downloaded from the National Instruments website for free Go to www ni com Problems with communication over the USB port The USB driver must be installed and the LabProUSB dil file must be present on your computer The LabProUSB dil is part of the LabPro folder of the DCU CD and it should be placed into the user lib folder of your computer The USB driver called windrvr6 sys is automatically installed when you install Logger Pro 3 3 An installer is also available from our website at www vernier com drivers In some instances you may have to have LabPro plugged in before starting LabVIEW LabVIEW quits unexpectedly Do not unplug the USB port while LabVIEW is running Restart your computer Problems finding LabPro Do not have other programs such as Logger Pro running that also use the serial or USB ports In some instances you must have permission for the serial port and USB port Old and new driver files have become intermixed Delete old
54. ble labpro flush labpro write s 3 01 1 0 chr 10 labpro write g chr 10 Buffer LabPro ReadAll Reads the incoming data labpro flush clears the buffer lblcurrent text mid labpro lookahead 5 1 mid labpro lookahead 7 1 mid labpro lookahead 8 1 Data Format of LabPro Data LabPro sends data back in a format similar to this n nnnnnE t nn In order to get this data translated to floating point numbers value we us the following lines of REALbasic Mantissa Val Mid Buffer 1 8 Val Mid Buffer 10 3 Current value Mantissa Pow 10 exponent Exponent New versions of REALbasic can handle this string to number conversion more easily With them you can simply use Buffer Trim Mid Buffer 4 13 Current value Val Buffer We chose to use the more complex mantissa exponent version in both the OS 9 and OS X versions for consistency Collecting Data as you Control Outputs The DCUTEMPC program is a good example of this kind of programming It uses a 1 command in the 3 command and monitors a temperature as this loop continues If the temperature hits limits the program branches to other code Making Sure LabPro Finishes before the REALbasic Program Moves On One thing that can cause confusion when programming the DCU occurs when the computer goes on with its program before the LabPro has time to finish what it is doing For example you may send commands to the LabPro t
55. ble T After that call the subprogram Here is an example of turning on the first three DCU lines for 10 seconds 7 D 10 T prgmDCUPWRON Using 1 in the Command 3 Line of DCU Calculator Program As with programs for sensors you can use 1 as the number of readings in the command 3 line In this type of program the LabPro CBL 2 will step through the patterns of outputs each time the Get command is encountered You must set up a sensor channel and then use a Get command to step you through the pattern Here is a sample program showing how the DCU can be controlled in this way prgomDCUINIT Initialize the LabPro CBL 2 1 1 1 Le Set up CH1 to read an AutoID sensor Send L6 1 31 6 1 2 4 8 13 14 L6 Set up digital output to turn on six lines in order one at a time Send L6 3 1 1 0 L6 Set up the LabPro CBL 2 for one step at a time Send L6 Lbl A Label for looping Get I Get the meaningless reading from the LabPro CBL 2 Goto A Repeat This program turns on the six lines of the DCU one at a time in order Notice that the timing of the program execution is still controlled by second number in the 3 command TEN character TI uses two different lt lt subtract Calculator users may also be confused about the keystroke to use to type the character on their keyboards For the TI 83 84 families you want to use the key labeled not the key Reading a Sensor at the Same Time that Y
56. cal use here is how you will probably want to use the 401 command For Ramp Sawtooth Triangle and Square Waveforms made up of only positive voltages Choose the waveform you want 2 Ramp Up 3 Ramp Down 4 Triangle 5 Square Use zero for Offset Set the amplitude parameter by dividing the peak voltage you want for the waveform by 0 0024 volts Set the period as you want remembering it is in milliseconds To calculate the period if you know the frequency use this calculation period in ms 1 frequency 1000 For Positive DC steady Voltages Use waveform 1 offset and period 0 Set the amplitude parameter by dividing the positive voltage you want by 0 0024 volts For example to get a steady 2 4 volts output use 401 1 1000 0 0 For Negative DC steady Voltages This is a little strange because you set things up for negative voltages using the offset parameter Use waveform 1 amplitude and period 0 Set the offset parameter by dividing the negative voltage you want by 0 0012 volts For example to get a steady 2 4 volts output use 401 1 0 2000 0 To Set the Output Voltage to Zero Use waveform 1 amplitude offset and period 0 Note that this is not quite the same as setting the analog output waveform 0 Off which leaves the analog output disconnected and perhaps floating at a non zero voltage For Sine Waveforms Centered at Zero Sine waveforms are very different from all others The reason is th
57. ch means LabPro will spit out data at the sampling period until told to stop You will find that this style of data l Digital Control Unit User s Manual collection does not mix well with analog output It can only be done if you re configure the sampling period after every time you set an analog output If you are just interested in writing a program to collect sensor data without intermixing digital or analog output study the DCUWARNYV program Remove the code used for digital output the Case Structure and add a control for the Sample Time node found in the RTSamplingSetup Express VI Perform these two steps and you will have created a simple data collection program Direct Digital Output A direct digital output simply means that a digital line or lines is turned on and remains on until modified or turned off This is simply a matter of sending LabPro a 2001 2011 or 2012 command We use the 2001 command frequently in the DCU programs with a subVI called Action Digital Out vi Look at the program called DCUTEMPC to see an example of how this subVI is used In this program a sensor is monitored until the data reaches a certain value at which time a line is turned on or off The subVI creates a 2001 command string and all you must do is enter the value as a string that will tell the DCU what lines to turn on and off For more information on the 2001 command and the values that are used for turning lines on see the
58. ctions While these sections do not cover the specifics of the different programming languages that can be found in later sections they do cover the specifics for sending commands to control the LabPro or CBL 2 The first of these programming sections Programming Overview discusses what a command is how to send it and how to initialize the LabPro CBL 2 at the beginning of every program The next programming section Programming for Data Collection goes into the different techniques used for collecting data from analog sensors Examples of how to perform these techniques and what commands to use are given The third programming section Programming for the DCU describe the two techniques for performing digital output direct control and sequence control This section explains the two techniques and provides an example for each The last programming section Programming for Analog Output Control goes into the details of how to control the LabPro analog output driver At the end of each section except the Programming Overview you will find programming challenges Programming specifics are the topic in the next six sections However unlike the previous programming sections these sections are specific to the three programming environments Each programming language has two sections that are devoted just to them Study the sections that pertain to your programming environment calculators REALbasic or LabVIEW In the next two sections Connectin
59. ctor on the DCU Note the LabPro and CBL 2 do not have an on off switch and they will turn on or off automatically 4 Connect the calculator to the LabPro CBL 2 using the round calculator link cable Make sure this connector locks in place 5 Start the DCUTOGGL program If you complete all of the steps above correctly the green LED on the DCU should turn on momentarily If the green LED does not come on double check all the steps Note that the electronics in the DCU can sense when it is properly connected to the LabPro CBL 2 and when the unit has power 6 Try pressing the key on the calculator If everything is working properly the red LED labeled 1 should go on Press the 1 key again and it should go off Try to turn on and off the other LEDs using the 2 through 6 keys Note that there are some combinations of LEDs that are not allowed so that in some cases when you turn on an LED some others may go off This DCUTOGGL program is very useful in testing hardware that you connect to the DCU 7 Quit the DCUTOGGL program by pressing the key 8 Start the DCUCOUNT program The red LEDs should go through a series of patterns with a change every second There are 16 steps that are the possible output patterns of the DCU They represent sending the numbers 0 1 2 3 4 15 to the DCU from the calculator followed by a 0 to turn all the outputs off again Notice that the first 12 steps correspond to binary counting using the first 4 red
60. d Control Kit RCK DCU Drive a stretched string from a small speaker Use a small speaker with a paper clip glued to it Mount the small speaker with the cone pointed upward Connect an elastic cord to the paper clip The other end of the cord should be attached to a solid object such as a ring stand For software to drive the function generator of the LabPro you can use either the FUNCTGEN or ANOUT programs When LabPro produces the right frequencies you can produce a number of standing wave patterns We have used several different small 3 to 5 inch speakers Some work better than others The speaker included in the Robotic and Control Kit RCK DCU was selected because it works well and has a higher than usual impedance so that it does not draw too much current We like to use a stretchy cord like the kind that is used on name tags at conferences We usually have a string length of a little less than a meter Because of the fact that the analog output frequency resolution is much better at low frequencies than higher ones you should use a low fundamental frequency in this demo Start with the loosest string you can get that vibrates nicely Start the FUNCTGEN program and set it for a 4 volt sine wave output We usually start with a frequency of about 20 30 Hz Experiment with the length and tension until a good standing wave pattern is obtained with the second or third harmonic Carefully and slightly adjust the tension length until you
61. d from LabPro until all of the requested data are collected This Express VI is used to collect data in NRT from the active analog channels 1 4 made active in the Init amp ChannelSettup Express VI Once all of the data is available this Express VI will return the data in array format Single Data Point This Express VI lets you read one data point from any channel configured by the Init amp ChannelSettup Express VI 49 Digital Control Unit User s Manual RTSamplingSetup This Express VI lets you set the rate of data collection for real time data collection In typical RT data collection programs the active channels configured in the Init amp ChannelSetup Express VI will begin collecting data as soon as this Express VI is called The Express VI called RTReadParse is then placed in a loop to collect the data RTReadParse This Express VI reads real time data after you have configured the channels and set the data rate Note that there is nothing to configure in this VI Analog Out This Express VI controls the analog output driver on LabPro Channel 4 Output begins immediately regardless of data collection mode and will remain active until LabPro is reset or disabled this can be done with this Express VI or with the StopResetClose Express VI Dig Out Direct This Express VI configures the DigSonic channel s to perform digital output LabPro s DigSonic channels can be used to perform digital output during a sampling run This provides
62. d to install the NI VISA driver software This driver is part of the LabVIEW installation CDs from National Instruments If you did not install this driver when you installed LabVIEW do it now It can also be downloaded from the NI website www ni com An Overview of LabVIEW LabVIEW is a graphic programming language LabVIEW programs are known as virtual instruments or VIs A LabVIEW VI has two main parts the Front Panel and the Block Diagram The Front Panel is the user interface with buttons and controls and also displays The Block Diagram is the code controlling how the VI functions To toggle between the Front Panel and Block Diagram displays on screen press the Control E keys Windows Alt E keys Linux or Open Apple E keys Macintosh We have provided a collection of VIs and Express VIs that perform the low level commands to the LabPro These VIs will be the building blocks of our DCU programs and for your own custom programs Study the Block Diagrams of the sample VIs and the information within this section to help you understand how to use these LabPro VIs Trying out a LabVIEW Program DCUTOGGLE To see a LabVIEW program in action controlling the DCU try the DCUTOGGL VI This VI allows you to control the DCU output lines with button presses First prepare your hardware 1 Connect the DCU to the connector on the top right side of the LabPro labeled DIG Sonic 1 Make sure this connector locks in place 2 Connect a LabPro
63. digital output patterns 3 Use aCommand 3 to initiate the sequence of outputs and specify the total number of steps to be taken Example 1 Here is a very simple example This program flashes on and off the first three lines of the DCU Call the subroutine DCUINIT intialize Send Out 1 31 2 7 0 set up sequence Send Out 3 0 5 8 0 start through the sequence Initialize The first line uses the DCUINIT subprogram to initialize the LabPro CBL 2 Command 1 The Command line is used to set up the digital output channel and specify the sequence of output patterns to be used Command is a little different when used with digital output than it was with sensors The syntax for Command 1 when used with digital output is 1 channel of output patterns patterns Here are the important parameters e Channel For digital output you use a 31 for the DIG Soniclchannel If you are using a LabPro you can also use a DCU connected to DIG Sonic2 and in this case the channel is 32 All of our sample DCU programs except DCU2 for LabPro only use 31 for the digital output channel e of output patterns The third number in the list is used to specify the number of patterns in the sequence to be output The number of patterns can range from to 32 In our sample program the number 2 is used This means there will be two output patterns in the sequence e Patterns This is a list of numbers specifying the output patterns to be used Again th
64. e There are several versions of the programs that allow you to control the DCU using either computers or calculators The CD can be used on Windows Macintosh or Linux computers On the Windows Linux segment of the CD we include e LabVIEW 6 1 or 7 programs VIs for Windows or Linux operating systems e DCU programs for all of the following Texas Instruments graphing calculators TI 73 TI 83 83 84 TI 86 TI 89 TI 92 and TI 92 You transfer these programs from your Windows computer to your calculator by using the TI GRAPH LINK cable and TI software e Windows or Linux applications that are ready to run no programming environment required DCUTOGGL DCUSTEP3 DCUSERVO and FUNCTGEN These applications will let you try out the DCU and analog output lines even if you are not a programmer On the Macintosh segment of the CD we include e LabVIEW 7 programs VIs which may be run on Macintosh OS X e LabVIEW 6 1 programs VIs which may be run on Macintosh OS 9 e REALbasic 5 5 versions of the programs to run on Macintosh OS X e REALbasic 3 5 versions of the programs to run on Macintosh OS 9 l Digital Control Unit User s Manual e DCU programs for all of the following Texas Instruments graphing calculators TI 73 TI 83 83 84 TI 86 TI 89 TI 92 and TI 92 You transfer these programs from your Macintosh computer to your calculator by using the TI GRAPH LINK cable and TI software e Macintosh OS X or Macintosh OS 9 applicati
65. e are now LEDs of many different colors there are even two color LEDs that will produce red if the current flows one way and green if the current flows the other way If you quickly switch the polarity of a bipolar LED you get orange It is easy to get the lamps and LEDs to flash in any pattern you want Many of the sample programs included do this Moving Displays and Kinetic Sculpture Simple DC motors can be used to create rotating or moving displays Mount a colorful disk on a motor and have it spin to attract attention Wrap a string around the shaft of a motor and hang a sign from it so that when the motor turns the sign moves up or down Consider using LEGO or Fischertechniks construction kits for these projects Solenoids Solenoids are electromagnets that can be turned on to make a piece of metal move a short distance When using solenoids check the voltage rating and also make sure that the current the solenoid draws is not too large 65 Digital Control Unit User s Manual Beeps and Buzzers Almost all computer systems have a beep sound that can be made when the computer wants to get the attention of the operator Most calculators don t make sound but you can add one using the DCU There are several different types of buzzers that you can use Some buzzers need only to have a steady voltage applied and they will produce a sound The sound continues until the circuit is turned off Our program DCUTOGGL can be used for this t
66. e your own programs e The DCU can provide a useful tool for student or teacher projects Use one of the many projects listed here or create your own The sample programs we provide may do what you need or most of what you need If so start with that program and modify it as necessary Use the subroutines we provide as building blocks for your own programs e Teaching the basics of digital and analog output and control can be accomplished without introducing programming in several different ways Computer users can use the Digital Control Unit with Logger Pro 3 3 and newer versions Logger Pro is a general purpose data collection program for LabPro and Vernier Sensors but it also supports setting up the DCU to turn on or off digital devices when a sensor reading reaches a specified limit You can also set the digital lines to come on at specified times Logger Pro also allows you to control the LabPro analog output line Computer users can also use the simple applications that we provide on the CD to control the DCU lines and the analog output lines There are applications for Windows Macintosh OS 9 Macintosh OS X and Linux Calculator users can use the calculator programs as they are on the CD with no programming required DCU Project Ideas Over the years we have used the Digital Control Unit for dozens of projects some whimsical and some practical Here are some of the projects we have built at Vernier You probably have
67. eads or make a table indicating a color code of the wires to each hole Safety Note When making your own cables if you leave the wire exposed and it touches a ground wire you could have a direct short of the DCU power supply If you leave it exposed it could short out against one of the other bare wires This could damage the power supply To avoid this once you identify the 9 lead wires on the cable cut the bare wire off of the connection This lead is not used very often We have cut this wire on the prepared cable we include with the DCU What can you connect to the DCU output lines The general answer is any electrical device which is meant to run on DC electricity at a voltage that matches the voltage you are using for your power DCU power supply Most of the time the LabPro or CBL 2 power supply is used with the DCU and it is a 6 volt power supply If you are using this power supply you should use 6 volt devices Thousands of different motors stepper motors lamps buzzers solenoids and other devices are designed to run at 6 volts The Vernier Robotics and Control Kit RCK DCU includes many devices of that sort ready to use with the DCU Connecting One Simple Non Polarized Device To connect a simple non polarized electrical device such as a lamp DC motor not a stepper or servo motor resistor or electromagnet that you just want to turn on or off use this wiring pattern Wiring a Simple DC Electrical
68. ection is usually used when you want to take data very quickly at hundreds or thousands of points per second This program is configured to collect data from a Vernier auto ID sensor automatically recognized and calibrated by the LabPro CBL 2 connected to Channel 1 This program will take 50 readings 0 25 seconds apart The specific commands and parameters are as follows Initialize with Command 0 Reset LabPro CBL 2 Send Out 1 1 1 Set up channel 1 Send Out 3 25 50 0 Start NRT data collection Get Resulting Data Get data 10 Digital Control Unit User s Manual Command 0 The first line resets the LabPro CBL 2 This is a common command for initializing at the beginning of a program You will find this command as well as other setup commands in all of our initialization subroutines or subVIs Command 1 The second line of our pseudocode is used to set up the channel for reading data The 1 command specifies a number of things about how data is to be collected The syntax for this command when used with sensors is 1 channel operation postprocessing statistics conversion The first number the 1 represents the command The numbers that follow are the parameters Not all of these parameters are important and you will rarely use most of them all Here are the important parameters we use in this simple program e Channel The input channel is specified with the second number in the list For analog sensors you can use 1 2
69. ement to retrieve the sensor reading from the LabPro CBL 2 In this case the calculator program will know that it cannot go on until the LabPro CBL 2 has finished its operation and returned readings to the GET instruction Here is the same program revised so that first sequence of outputs will be completed before the power is turned off prgmDCUINIT Initialize the LabPro CBL 2 1 1 1 L6 Set up CH1 to read a sensor Send L6 1 31 2 0 7 Le Set up digital output to turn on and then off the first three lines Send L6 3 1 10 0 LS6 Go through 10 steps each taking 1 second Send L6 Get L1 Get the reading The program will wait 2001 0 L6 Set up digital output lines for turning power off to all lines Send L6 Here are some things to remember about the programming trick discussed in this section e You do not need to have a sensor connected when you use this trick e It makes no difference what value is returned in the GET statement It is just a way of forcing the calculator program to wait for the LabPro CBL 2 to finish its work e If you happen to want your program to take a sensor reading at the same time it is executing some pattern of digital outputs then this same idea will work and produce useful data Another good reason for using subprograms in your DCU programming is to avoid confusion of this sort If you need to turn on a line for a specific time use the subprogram DCUPWRON Simply specify the outp
70. ensors will lack the auto ID feature 12 Digital Control Unit User s Manual To read calibrated data from one of these non auto ID sensors you need to handle calibration in the program Here is an example using NRT data collection Send Out 0 initialize LabPro CBL Send Out 1 1 1 0 0 1 set up channel Send Out 4 1 1 0 809 0 077 specify calibration Send Out 3 0 25 50 0 start data collection Get Resulting Data get data measured values first then times This program is similar to the first example in this section but the difference is that this program is for a sensor that does not have the auto ID feature The changes are in the second and third line Command 1 The second line of our pseudocode is used to set up the channel for reading data As mentioned earlier the full syntax for this 1 command when used with sensors is 1 channel operation postprocessing statistics conversion In the auto ID probe example we only used the channel and operation parameters This example also uses the conversion parameter If the conversion parameter is set to 1 it tells the LabPro that it should use the calibration provided in the 4 command that follows Command 4 The third line of our sample uses the Conversion Equation Setup Command Command 4 is only used to set up the calibration equation for a non auto ID analog sensor With the proper Command 4 line the LabPro CBL will read voltage and convert to the correct values atmosp
71. eriment with our other subprograms to develop your own programs There is a lot more to learn The best advice we have is to experiment The best way to learn programming is to actually do it Additional Notes on Calculator Programming This section offers specific tips for people writing TI calculator programs For more information also see the LabPro Technical Reference Manual Getting Started with the CBL 2 and the manuals that came with your calculator The exact details of programming differ somewhat between calculator models You should carefully study the manual that came with the calculator you are using Concentrate on the sections about programming Also examine some of the programs that you use with the calculator No matter what calculator model you are using the commands you send to the LabPro CBL 2 are the same All the sample programs listed in this manual use the syntax of the TI 83 or TI 84 calculators To see versions of the same programs for other calculators simply open the appropriate version of the program from the CD using TI GRAPH LINK or TI Connect Our number one tip on programming for TI calculators is that most programming should be done using a computer and typing on a keyboard Use TI GRAPH LINK or TI Connect for the editing and then send the program to the calculator Typing or modifying a program on the calculator keyboard is much harder Also most versions of TI GRAPH LINK have built in tools to make writing
72. ese are the numbers from the table above In our example they are 7 and 0 Note that in this example since the of output patterns set in the command was 2 then there have to be 2 numbers in this list Command 3 The 3 command is used much like it is with sensor programs 3 samptime numsamp trigtype The important parameters and what they mean in this example are as follows e Samptime This is the time between samples in seconds The range is 0 0001 to 16000 s e Numsamp This is the total number of steps to take through the sequence This can be any integer from 1 to 12 287 or 1 for a continuous sequence Note that this number does not have to match the of output patterns used in the Command 1 For example in the sample program above of output patterns is two there are two output patterns in the sequence The numsamp used in Command 3 is eight This means that the program will go through eight steps When it finishes the sequence of patterns specified in Command 1 it will start through the sequence again The sequence of two elements will be repeated four times for a total of eight steps Think of the sequence as a loop that will be worked through as many times as needed until all the steps have been executed e Trigtype The default value of this parameter is 1 which is for manual trigger You have to press the Start Stop button on the LabPro CBL 2 to start the digital output going You usually do not want this so al
73. g Devices to the DCU and Connecting Devices to the LabPro Analog Out Line the manual switches gears to focus on the hardware Here you will find information for connecting all sorts of devices such as speakers polarized devices non polarized devices LEDs DC motors stepper motors and servo motors The final section DCU Project Ideas provides tips and suggestions for some exciting projects Choose one of these projects or use the list to help brainstorm your own project idea These projects combine use of the DCU and analog output driver with programming electronics design and engineering Acknowledgements The Digital Control Unit was designed by John Wheeler Dr Fred J Thomas of Sinclair Community College Dayton Ohio and mathmachines com pioneered the use of the digital outputs of the CBL 2 and provided valuable suggestions for this project Matthew Denton Ian Honohan Jeffery Hellman Laura Owen and Adam Higley created and tested most of the sample DCU calculator programs and projects we built Jeffery Hellman David Stroud Sam Swartley Cole Wardell and David Vernier wrote most of the sample DCU computer programs Thanks to Michele Perin Sam Swartley John Gastineau Kelly Redding Christine Vernier Erik Schmidt Jan White Dan Holmquist Gretchen Stahmer DeMoss and Ian Honohan of Vernier Software amp Technology for their editing and testing Thanks to Adrian Oldknow for encouraging me on this project Thanks also to Scott
74. g Window Help DCUCOUNT E Menu s OM C BlankwaitTemp Window wj a Ed commerror 5 Placement 0 Default V i 585 Height 372 Minwidth 64 MinHeight 64 Maxwidth 32000 MaxHeight 0 Document Y DCUCOUNT Outputs the HasBackColor Z sequence 0 15to the BackColor DCU Backdrop None Title DCUCOUNT Visible oO FullScreen Lj MenuBarvisible f Press and Hold Space to Stop SubRoutine Close Box Ed 2 Growlcon T Zoomlcon LJ BalloonHelp m MacProelD 0 Z LI View of the Main DCU Window Mac Classic Version Key parts of a REALbasic program are labeled with numbers on the figure above We will try to explain what each of these numbered windows and objects does below 1 This is the main window of the program with the user interface It is technically referred to as the Window Editor It controls what the application that we have developed looks like Notice that there are several different objects on this window including two buttons several labels and a large white listbox at the bottom This window is how the program gathers input from the user and also how it displays output to the user as well 2 Mac Classic Only One object displayed on the screen displayed above is only used on the Mac Classic version of these programs It looks like a Mac modem printer symbol This is the Serial Communications Control This con
75. g you wish to do In any case review sample programs to better understand the VIs and how to program the LabPro using LabVIEW 48 l Digital Control Unit User s Manual LabPro VI Palette Overview Here is a summary of the VIs found in the LabPro folder and accessed from the User Libraries function palette When you have properly placed the LabPro folder in the user lib folder you will have access to the LabPro palette of VIs by going to the User Libraries function palette The VIs in this palette are the building blocks of a LabPro program sending and reading commands to LabPro via the serial or USB port When you build a LabPro program you should place the appropriate VI on your block diagram provide the proper inputs and wire the VI in such a way that it will occur in the proper sequence Use the DCU Manual the LabPro Technical Reference Manual and example VIs to help you understand how to use these VIs properly In addition when a VI is placed on the block diagram you can turn on the Show Context Help in the Help menu and get information about the VI by placing your cursor over the VI Here are the most commonly used VIs isi HEENA Dig Out Direct 2 Source vi LabPro Assist Init amp Channel StopResetClo CollectNRT 2 1PT p j SingleDataPoi RTSamplingS RTReadParse_2 z Analog Out 2 Dig Out Direc Dig Out Sequ The LabPro Express VI palette is accessed by placing your cursor over the LabPr
76. hat allows the user to toggle the digital lines with the keypad or mouse click Note that it takes a second or so for this program to respond to a key press on calculators Also not all possible combinations of outputs are possible Use this program to test hardware that you wire up to the DCU DCUTRAP2 Used with a photogate connected to DIG Sonic 2 this program can be used to make a live trap It monitors the photogate to detect an animal turns on D1 to take action then pulses D2 on and off DCUTRAP3 Another live trap program this one uses stepper motors Monitors photogate connected DIG Sonic 2 to detect animal then activates a directly connected stepper motor to lower a trap door DCUWARNV Monitors the analog sensor on Ch 1 of the LabPro CBL 2 and turns on the D1 output of the DCU if the level exceeds a limit This is a good sample program to start with for any project involving monitoring an analog signal and taking action based on the reading Analog Ouput Control Programs O Z O ZO S O ANOUT This is a simple program to show how you can control the analog output line of the LabPro and the function generator Use this program if you want to examine modify or customize the code used for controlling analog output FUNCTGEN This program is a fairly complete function generator program You can use it to set a DC voltage output or set up an output waveform Use this program if you want to test hardware connected to the analog outp
77. hat you are using LabVIEW 7 This means that the Express VIs are used in examples and frequently discussed If you are a LabVIEW 6 user you do not have access to Express VIs but the information is just as valid Our LabVIEW 6 VIs have replaced the Express VIs with subVIs that have the same name the same icon and the same functionality The programs look and perform the same The only difference of course is that you will not see the big blue field that surrounds the icon and you must configure a subVI by wiring in values not with the use of a popup dialog box Separate versions of DCU sample programs for each of these computer operating systems are provided on the DCU program CD LabVIEW 7 0 or 7 1 e Windows computer with either serial or USB connection to LabPro e Macintosh OS X computer with USB connection to LabPro e Linux computer with serial connection to LabPro LabVIEW 6 1 e Windows computer with either serial or USB connection to LabPro e Macintosh OS 9 computer with serial or USB connection to LabPro e Linux computer with serial connection to LabPro Setting Up the Files On the CD that came with your DCU there is a folder that combines the name of the operating system Windows Linux Mac OS 9 or Mac OS X and the version of LabVIEW LabVIEW 6 1 or LabVEW 7 0 Copy the appropriate folder to your hard disk and follow the directions below 1 The folder that you moved to your hard disk contains two subfolders named LabPro and
78. he LabVIEW Troubleshooting Help section of this manual The six buttons on the screen correspond to the DCU lines 1 6 This program will allow you to turn these lines on and off Try clicking the mouse on the D1 button on the screen Look at your DCU the red LED labeled 1 should go on If you have any electrical device connected to D1 it should be turned on Press the D1 button again and it should go off Try to turn the other LEDs on and off using the D2 through D6 buttons on the screen Note that there are some combinations of LEDs that are not allowed see the table of digital outputs in the DCU Overview section If you make a click that would set up an output pattern that is not permitted the red error warning button on the right of the screen will go on and the output pattern will not change The DCUTOGGL VI is very useful in testing hardware for your future projects that you connect to the DCU When you are finished experimenting with the DCUTOGGL program click on the Stop button at the bottom of the screen to terminate communication with the LabPro and end the program It is not recommended that you stop the program by clicking on the red Stop icon on the toolbar This button should be reserved for emergency stops only because it will abruptly stop the program and could leave the LabPro or USB port in an unusual state If you want to examine the Block Diagram of this VI choose Show Block Diagram from the Windows menu This V
79. heres newtons degrees etc The syntax for this command is 4 channel equation type KQ k1 There are lots of options for this command and the details are in the LabPro Technical Reference Manual Fortunately most probes use linear calibrations 1 st order polynomial equation type 1 and things are fairly simple The parameter kg represents the y intercept and the parameter k represents the slope units volt In our sample program this means that Channel raw voltage will be converted to proper units using a linear equation with a y intercept 0 809 atm and a slope of 0 077 atm volt This is the proper calibration for a Vernier Barometer calibrated in atmospheres Information on the proper slope and y intercept values for each Vernier sensor is included in the sensor s documentation Programming for Data Collection Summary This has been a summary of the most important things about writing LabPro CBL 2 programs to collect data There is much more you can learn Even so this should help you get started The best ways to learn programming are e Study other programs that read sensors including the sample programs on our CD such as DCUTEMPC and DCUWARNYV or the computer programs RT and NRT Check out programs that your teachers or friends have written or download some from the Internet e Jump right in and start changing the programs and notice what happens e Refer to the LabPro Technical Reference Manual for more inform
80. his VI we do this and then we add one second 1000 milliseconds to the delay just to make sure there is time for the pattern to finish executing B LOSE d b StopResetClose_ Comm port gt Error In Once the pause time elapses the last piece of code becomes active StopResetClose_2 is an Express VI whose function is to properly end the program and shut down the LabPro including freeing up the computer s USB or comm port It is very important to end a program by properly closing the computer s USB or comm Port Modifying the Program It s now time to customize DCUCOUNT and make it do something different We are going to make two changes We will modify the program to make it tum on DCU lines 1 and 2 for 3 seconds before the counting sequence starts and also modify the program to make it go through the counting more slowly 42 l Digital Control Unit User s Manua The easy change to make to the code is to change the rate of going through the sequence In the part of the code below all we have to do is to change the Samptime input Let s change the time between steps from second to 2 seconds 2 0 umpoints 1 for RT mode Now let s enter the code that will turn on lines 1 and 2 before the sequence starts datai data2 dataN The LabPro folder has a collection of subVIs and Express VIs for many different tasks The one we will use pictured above is named Action_Digital Out v
81. i This simple subVI sends a 2001 command to the LabPro which tells the LabPro to perform a direct digital output for more information on the 2001 command refer to the Programming for the DCU section of this manual The inputs nodes into the VI are labeled datal data2 data N Comm port and Error In To set DCU output lines 1 and 2 both on we need to send a data value of 3 to the LabPro To do this we create a constant for the subVI s data1 data2 data N node and wire in a value of 3 Note that this node expects the input to be a string not a numeric so make sure your constant is a string constant The Action_Digital Out subVI turns on the two lines now you need to add a delay so that the two lines will stay on for 3 seconds before the sequence starts One way to perform this delay is with the use of the pause vi which was discussed above The input to this subVI is delay time in milliseconds so we should use 3000 ms 3 seconds The block diagram picture below shows the modified VI Note that the Action_Digital Out and pause subVIs had to be added into the code right after the LabPro was initialized To do this we had to break the error line and weave it through the new subVIs to make them happen in the right order Also the Action_Digital Out subVI requires the comm line to be wired so it knows which comm port the LabPro is using 43 l Digital Control Unit User s Manua DCUCOUNT vi Block
82. il the photogate is blocked DCUPWRON 1 1 this is a method to turn the power on to D1 for 1 second DCUPULSK 2 this is a method pulse the power on and off to D2 For the Stop button the Action is DCUOFF this is a method to shut off all lines All the complicated code for this program is in the methods we have provided How commands are sent to LabPro for controlling the DCU LabPro is controlled by sending a string of integers called a command out through the serial or USB port In REALbasic we use the following code which sends data to LabPro LabPro Write s integer string chr 10 The command is in the curly brackets The rest of the code tells the computer where to send the data LabPro Write and sends a carriage return at the end of the command ends chr 10 This format works for all the versions of REALbasic and for both serial and USB connections if you have the driver files loaded on your computer as suggested at the start of the REALbasic section of this manual If you wanted to have the LabPro turn on line using the 2001 command you would use the following line in REALbasic LabPro Write s 2001 1 chr 10 Interrupting the Program When writing the subroutines such as DCUCHKD and DCUWAITD for REALbasic we were not able to find a way to provide a functional Stop button Instead we designed these methods to stop on the press of the Space Bar There is code to check for a press of the Space Bar and break out
83. ing subprograms in your DCU programming is to avoid confusion of this sort If you need to turn on a line for a specific time use the subprogram DCUPWRON Simply specify the output you want D and the time you want the pattern held T and all this will be taken care of for you Power Control and DCU_ INIT Whenever you use LabPro for Digital Output you probably want to set the LabPro to leave power on at all times You do this with the following command LabPro Write s 102 1 chr 10 We do this in the DCUINIT method and the best way to start a DCU program is to simply use a call to the DCUINIT method as described below The DCUINIT method does several things First it opens the serial or USB port It then checks to see if LabPro is properly attached to the port and powered up This is done by sending a 7 command to the LabPro a system status request If properly connected and powered LabPro responds by sending back a long string of characters We have the computer sleep for 200 milliseconds and then examine the data returned If we verify that a LabPro is properly connected we indicate so in the list box If the proper string of data is not returned a Dialog box is displayed to inform the user of an error in communication This dialog allows the user to retry the connection until it is successful Finally the DCU_INIT routine sets the LabPro power to be always on REALbasic Data Collection Programs for LabPro We have included
84. ips for people writing REALbasic programs We hope to warn you about some of the things that can cause confusion when you start DCU programming REALbasic Windows When using REALbasic you may find it confusing dealing with the various parts of a sample program Here are some tips To see the user interface of the program select Project from the REALbasic Window menu and then double click on the window you want It is often named Main or sometimes has the name of the file for example DCUCOUNT To see the code associated with one of the buttons double click on that button Once you have displayed some of the code you can also choose Code Editor or Source Code from the Windows menu to get back to the code Sometimes in REALbasic windows get hidden behind one another strangely Try moving things around if you lose a window REALbasic Methods We have provided you with subroutines called Methods in the REALbasic that you can easily use These methods are included with each of the sample programs So for example you can attach a method that monitors a photogate and reports the status By doing this you can fairly easily set a program up so that when the user clicks on a button the program will begin monitoring a photogate This is much simpler than trying to write your own code to monitor the photogate To examine or modify these methods select Code Editor or Source Code from the Window menu of REALbasic or double click on
85. l installations are complete the programs can be run one at a time The programs will have the names DCUSERVO exe DCUSTEP3 exe DCUTOGGL exe and FUNCTGEN exe The programs will be located on your computer in the location that you chose during the installation Browse to a program and double click to run e You should note that a folder called data was also created during installation It is important to keep this folder and the program together in the same directory Macintosh OS X USB connection e The programs and support files are found in the folder called Mac OSX DCU Applications Copy this folder to your hard disk in a convenient location Digital Control Unit User s Manual e The LabVIEW 7 0 Mac OSX Runtime Engine must be installed on your computer This installer is included in the Mac OSX DCU Applications folder The name of the installer is LabVIEW 7 0 Runtime Engine OSX Run it to start the installation e You must have the USB driver installed We do not have an installer for the Mac OS X driver Therefore you must have Logger Pro 3 3 installed Installing a demo version of Logger Pro will also install this driver A demo version can be found at www vernier com downloads e When all installations are complete the programs can be run one at a time Browse to a program and double click to run Macintosh OS 9 USB or Serial connection e The programs and support files are found in the folder called Mac OS9 DCU Ap
86. line on and off at a frequency of a hundred hertz or so Our sample calculator program DCUBUZZ does this Wiring a Speaker Connecting a Polarized Electrical Device Some electrical devices are polarized that is they have a positive and a negative side They therefore must be wired in one particular way for use with the DCU Examples include some buzzers a few lamps and complex electronic devices LEDs are given special treatment below For devices that have positive and negative sides make sure you 57 Digital Control Unit User s Manua connect the negative side to ground Devices wired this way will be on any time D1 is high e5 et e3 l 3 ef RR G G Wiring a Polarized Electrical Device with Positive and Negative Leads You can wire up to six polarized devices in the same way using connections 1 6 for the positive leads and the G connections for the negative leads Connecting an LED Simple LEDs have positive and negative sides so make sure you connect the negative side to ground Also most LEDs need to be wired with a resistor in series with them in order to limit the amount of current that flows Typically this resistor has a value of 220 ohms or higher Check the specifications on your specific LED if possible The flattened side of the plastic part of the LED marks the negative side The positive lead is usually longer than the negative lead G G Wiring a LED with Positive and Negative
87. lines of code for the LabPro CBL 2 easier Check the TI manuals for information on how to use this feature Interrupting the Program Some of our calculator programs are very simple and do not even have a graceful way of stopping them Remember that on all TI graphing calculators repeatedly pressing the On key will stop the program Always start with the DCUINIT SubProgram You will save yourself a lot of trouble if you make the first line of every program prgmDCUINIT If you do this your programs will provide good feedback if they cannot communicate with the LabPro and the LabPro power down feature will be turned off so you do not get unexpected results 21 Digital Control Unit User s Manual Setting the DCU Output If you are using a LabPro and CBL 2 the command 2001 makes it easy to set the output pattern of the DCU To use it you simply use 2001 D L6 Send L6 Set output pattern to D Where D is the output pattern you want to set and hold It can be any integer from 0 to 15 To turn just the first digital output line on and leave it on until you send another command to turn it off use 2001 1 L6 Send L6 Having the DCU Output Hold a Setting for a Specific Time Many times you want to turn on a line for a specific time period The easiest way to do this is to use the DCUPWRON subprogram First set the output pattern you want in the variable D and the time the pattern is to hold in seconds in the varia
88. ly No part of this manual or its accompanying CD may be used or reproduced in any other manner without written permission of Vernier Software amp Technology except in the case of brief quotations embodied in critical articles or reviews The terms CBL CBL 2 Calculator Based Laboratory CBR TI Connect and TI GRAPH LINK are either registered trademarks trademarks or copyrighted by Texas Instruments Vernier LabPro is a trademark of Vernier Macintosh is a registered trademark of Apple Computer Inc IBM is the registered trademark of International Business Machines Windows is a trademark of Microsoft Corporation in the United States and or other countries REAL Software REALbasic and the REAL Software cube logo are registered trademark of Real Software Inc LabVIEW is a trademark of National Instruments Inc The term Linux is a registered trademark of Linus Torvalds the original author of the Linux kernel LEGO is a registered trademark of the LEGO group of companies Fishertechnik is a registered trademark of Fischerwerke All other names mentioned are trademarks or registered trademarks of their respective holders in the United States and other countries Published by Vernier Software amp Technology 13979 SW Millikan Way Beaverton Oregon 97005 2886 503 277 2299 888 837 6437 FAX 503 277 2440 www vernier com info vernier com Fifth Edition 2005 Second Printing Printed in the United States of America About This Manu
89. most always use a zero here This will have the digital output start as soon as the program executes the step 15 Digital Control Unit User s Manual So what does the sample program above do It has the digital output lines go through the following output pattern 7 0 7 0 7 0 7 0 The sequence 7 0 was specified in the Command line and this is repeated until 8 steps are made as specified in Command 3 If the DCU were connected when this program runs the first three red LEDs would flash on and off four times The status of the LEDs would change every 0 5 seconds Controlling a DCU Connected to DIG Sonic 2 or Two DCUs at Once LabPro Only Most of the discussion in this manual has assumed that the DCU was connected to the DIG Sonic connector We use numbers between 0 and 15 to control the status of those lines If you are using a LabPro you can connect a DCU to the DIG Sonic 2 connector You can use any number from 0 to 255 for D in the 2001 command and control any of the lines on either DCU Below is a table of how the 2001 command can be used to set the pattern on outputs on a DCU connected to the DIG Sonic 2 connector i ee ee TDS TBE o o eS eae ERG GE ae 16 o0 N TR N x ie ee e Ef ee N n ed 0011 X X Ca oa E E Q anal gt 2 3 gt x lt x EI RE wel e HERE SIE EES AE IE ME AE HE MIGE EE RE EDE AE EE WINE RAT TA BEE EES EE HE GE EE MIK KAR AE AE X gt lt gt lt
90. n a convenient location e If you plan to use a USB connection make sure the extension LabProUSB is installed on your computer This extension comes with the Vernier Logger Pro 2 or Logger Pro 3 program If you do not have this program installed on your computer you can download a free demonstration version from www vernier com drivers This file should be placed in the System Folder Extensions folder Trying out a REALbasic Program DCUTOGGLE To see a REALbasic program in action controlling the DCU try the DCUTOGGL program This is a program to control the DCU lines with mouse clicks Connect the DCU to the connector on the top right side of the LabPro labeled DIG Sonic 1 Make sure this connector locks in place Connect a LabPro power supply IPS to the round connector on the DCU Connect LabPro to the Macintosh computer using the USB or serial port cable Navigate to the location on your hard drive where you put the DCU REALbasic folder and open it Inside you will see a number files Double click on this on file called DCUTOGGL This will start REALbasic with the DCU program open On the right side of the screen you will see a window labeled Properties On the left side of the screen you will see a window of Tools and another window labeled Colors For now we will ignore these windows In the center of the screen you should see a window labeled DCUTOGGL This is the important window for now 27 Digital Control Unit User s Manual K
91. nd strings But if you look at the block diagram of these high level VIs and dig into the subVIs within these VIs you will eventually find the low level subVIs that perform the communication and send the string commands to LabPro When you are writing your program it is best to look for an Express VI or subVI in the palette that performs the required function Using these high level VIs should make your program cleaner easier to follow and faster to create However if you are interested in writing programs by sending string commands directly to the LabPro or if the high level VIs do not provide enough flexibility then you will want to use the low level VIs 47 l D igital Control Unit Untitled 1 Block Diagram File Edit Operate Tools Browse Window Help User s Manua Col OPEN Init amp ChannelSet up_2 Source vi Comm port Error Out LabPro Connectecr LabPro OS h Active channel art ry vy Dig Out Direct_2 Source vi gt Comm port Comm port out Error In Error Out ul glluele los ied StopResetClose_ Comm port Error In gt 14 This example program demonstrates the difference between high level and low level VIs The Dig Out Direct Express VI hides the 2001 command and is therefore considered high level The subVIs that send 2001 commands show portions of the 2001 command string and are therefore considered low level
92. nds this program Waits for a photogate connected to analog channel CH1 to become blocked Waits until the signal level on channel one exceeds a specified value DC motor control program Used to move DC motor controlled car Takes direction and steps as an argument and moves accordingly Stepper Control Program Used to move a stepper driven car Takes direction and number of steps as arguments and moves accordingly Change the value of T in the first line to control the speed 74 T Time and D digital output must be predefined D Direction and N Number of Steps D Direction and N Number of Steps must be predefined V Distance limit V Minimum Value must be predefined T Time and D Direction 1 forward 2 backward 3 left 4 right N Steps and D Direction 1 forward 2 backward 3 left 4 right Appendix B LabPro Only LabPro Only since CBL 2 only has one DIG Sonic port Appendix C Selected DCU Calculator Program Lists Here are some of the DCU programs listed for you to examine The programs listed here are TI 83 versions but the versions for other calculators are similar To see versions of the same programs for other calculators simply open the appropriate version of the program from the disk using TI GRAPH LINK You can also use TI GRAPH LINK to modify print and move these programs to your calculator Program DCUSTEP prgmDCUINIT 1 T ClrHome
93. nning as quickly as possible using a Macintosh computer and REALbasic It assumes that the user has some familiarity with RealSoft s REALbasic Information on this programming language is at www realsoftware com We have two versions of programs using REALbasic For Macintosh classic OS 9 users we have programs written using RealSoft s REALbasic 3 5 1 For Mac OS X users we have similar programs written with REALbasic 5 5 2 The sample screens below are from the OS 9 version but the OS X versions are similar Setting Up the Files Using the LabPro with REALbasic in OS X On the CD that came with your DCU you will find a folder Mac OS X REALbasic DCU Copy this folder to your hard disk in a convenient location To use the LabPro with REALbasic on Mac OS X you must first have two support files in the proper locations e VSTLADProUSBRB is a plugin You will need to put a copy of this plugin in your REALbasic plugins folder e The package VST_USB bundle is required to use Labro via a USB connection It should be placed in the same folder as the program you are using We have placed this bundle in the folder with all the DCU programs on the CD Just makes sure that when you copy REALbasic programs to other folders to keep this bundle with them or the programs will not work Using the LabPro with REALbasic in Mac Classic OS 9 On the CD that came with your DCU you will a folder Mac OS9 REALbasic DCU Copy this folder to your hard disk i
94. ntrolling data collection or output lines are generally the same The way the commands are sent to the LabPro CBL 2 depends on the programming language The LabPro CBL 2 is controlled by sending a list of comma separated numbers enclosed in curly brackets The first number in this list is what we refer to as the command Here is a list of a few command numbers and what they represent Command description All Clear Reset Channel Setup Sampling Setup Conversion Equation Setup Stop Collection Single Point Data Collection LO DA BR Wl rR oO The numbers that follow the command in a list are referred to as the parameters The parameters each have special meanings depending on what command you are using There is a default value for each of these parameters If you leave the parameter off the list the default value will be used In many of our examples we will only use parameters that are important and leave off the others so they will take their default values For a detailed list of the commands and parameters refer to LabPro Technical Reference Manual This manual is available free at www vernier com diy for Do It Yourself Here is sample code for sending out a 3 command with parameters 1 2 and 0 Notice the differences in how the command is sent in the various programming environments Using a TI 83 3 1 2 0 L6 Send L6 Using REALbasic LabPro Write s 3 1 2 0 chr 10
95. o have the DCU set an output pattern before an earlier series of operations are completed Consider this program for example LabPro Write s 1 31 2 0 7 chr 10 Set up the digital output to turn the first 3 lines on and off LabPro Write s 3 1 10 0 chr 10 Go through 10 steps each taking 1 second LabPro Write s 2001 0 chr 10 Set up digital output lines for turning power off to all lines 35 Digital Control Unit User s Manual If you try this program it will not operate the way you might expect If the DCU is connected you might expect to see the first three red LEDs flash on and off for ten seconds and then the power should go off Instead the LEDs will briefly flash but the program quickly ends with the power turned off Why The problem is that LabPro starts executing the sequence of 10 steps but then is sent a new command telling it to turn the power off It interrupts what it was working on and follows the new instruction There is a solution to this problem Use the Sleep subroutine method which is included in all of our sample programs to keep program from moving on while you wait for LabPro to finish a command The format of the command is Sleep X where X is the number of milliseconds to delay For example in the sample program above you could use Sleep 10000 This will cause the program to pause for 10 seconds We use this approach frequently in our sample programs Another good reason for us
96. o icon The top palette contains the LabPro Express VIs These are very high level VIs that perform most of the functions of the LabPro A description of the ten Express VIs follows LabPro Assistant Use this Express VI to verify that you have a good connection between your computer and the LabPro This is a stand alone Express VI that collects a single data point from a Vernier Analog Auto ID probe All of the steps required to collect one single data point occur within this VI including Open the port initialize LabPro configure the channel for an Auto ID probe collect a single data point and close the port This VI is not meant for use within a larger program just as a very easy way to get started with LabVIEW data collection Init amp ChannelSetup This Express VI locates and resets the LabPro identifies the comm line it is connected to and returns the firmware version of the LabPro if you want to know it Use this Express VI to configure your analog channels or your digital channels for the motion detector For example you can specify that you want to read an AutoID sensor on CH1 and a Motion Detector on DIG Sonic 2 StopResetClose This Express VI stops any data collection or output powers down LabPro and closes the computers USB or serial ports You must end your program by closing the port otherwise there can be unexpected and unwanted behavior CollectNRT Non real time NRT collection simply means that data are not returne
97. of values The inputs to the VI follow Comm port port number of the open port Ring Ring control with various pre programmed options to run 50 Digital Control Unit User s Manua Operation If you choose custom from the ring control you will need to input this parameter 0 clears the channel 1 32 Count number of output patterns in list List of values Values may be from 0 to 15 must have one value for each count cond chi en Configure_Analog CH1 Located in the Configure Channel subpalette There are similar VIs for CH2 CH3 and CH4 This subVI sets up channel 1 for data collection These VIs do not appear in the DCU example programs because the Init amp ChannelSetup Express VI performs the same function However these VIs provide more configuration options for the channels The string command that is created in this subVI is s 1 channel operation post proc delta equ The inputs to the VI follow Comm port port number of the open port Operation indicates the units of measure the channel should return use 1 to Auto ID the sensor Post Proc enables post processing to take place on data collected Since data is not stored in RT mode no post processing is allowed Delta always set to zero Equ Indicates if conversion equation is applied to data before it is returned ms to wait after amount of pause after sending the command gata calles 3 Config_DataCollectionSetup Located in the Data Collection s
98. og output line to a bi color LED The most common ones produce red when the current flows one way and green when the current flows the other way If you send a slow sine waveform out the analog output line you get a fascinating color transition from red to green to red If you send a high frequency sine wave to the LED it will appear orange Control the DC voltage to a lamp and monitor its current This is a great experiment to see the change in resistance of a lamp filament as it heats up You can also monitor the light produced by the lamp as it goes through the cycle Note that many lamps will draw more current than the LabPro analog output lines can supply A number 48 lamp rated at 2 V and 60 mA is perfect for these demonstrations One of these lamps is included in the Vernier Robotics amp Control Kit order code RCK DCU and also in the Vernier Circuit Board order code VCB You can use either the ANOUT or FUNCTGEN program to control the LabPro analog output line You might want to modify the ANOUT program to add the plotting of the output voltage You can also use Logger Pro 3 on Macintosh or Windows which has the advantage of automatically plotting a graph of the voltage and current vs time One note about how the function generator of LabPro works may help you understand how to best use this feature When you adjust the frequency of the analog output you are really controlling the period of the waveform in millisecond increments from 5 to 2
99. on and off To perform a custom pattern you will be choosing the first option from the Ring list called Custom input operation and list values and inputting values into the Operation and List of Values nodes See the section in Additional Notes on LabVIEW programming for more information on custom sequences 1 0 umpoints 1 For RT mode The 1 command was used to set up the digital output pattern LabPro must now be told how guickly the pattern should be executed time between steps how many patterns to output number of steps and when to start the output pattern The subVI Config _DataCollectionSetup vi sends a 3 command to the LabPro starting the output pattern The Samptime input determines the time between steps and the Numpoints input determines the number of steps There are also inputs for Error in and Comm port 1000 1000 00 The next part of the Block Diagram is used to provide a delay in the program to allow the sequence of outputs to execute on the LabPro Otherwise we might start an output sequence and then end the program before the sequence has had time to happen How long should this delay be We can calculate it since the time between steps and the number of steps are both known The subvi pause vi expects an input in milliseconds We can take the time between steps and multiply it by the number of steps to get the time delay needed in seconds To convert the delay to milliseconds we should multiply by 1000 In t
100. one of the button in the user interface window You will see a hierarchical menu at the left side of the window Open the Methods item and you will see each of the subroutines of the program listed as a separate method Click on any method and the code for that method is displayed to the right Methods are used by listing the method name in the code with any parameters to be passed to the method following the name For example with the DCUPWRON subroutine you call to it with a parameter set for the digital output pattern you want on and T set to the time you want the pattern to stay on The code below turns on the D1 line for 2 seconds DCUPWRON 1 2 Major operations that you want your program to handle can be replaced using one of the subroutines Many 33 Digital Control Unit User s Manual programs can be written by linking together these subroutines with a few lines of new code As an example consider the program DCUTRAP2 This program is used to make a bug trap It uses a photogate to sense when a bug is inside a box It then turns on a motor to close the lid of the box When the program opens the Method DCUINIT is automatically called The rest of the program is three buttons for the operations and each one has code assigned to its Action For the Check button the Action is DCUCHKD this is a method to check the photogate status For the Trap button the Action is DCUWAITD this is a method to check the photogate status and wait unt
101. ons that are ready to run no programming environment required DCUTOGGL DCUSTEP3 DCUSERVO and FUNCTGEN These programs will let you try out the DCU and analog output lines even if you are not a programmer How to Use the Sample Programs The programs on the CD can be used in several different ways e Use them unchanged for controlling electrical devices you build The sample program DCUTOGGL is especially good for trying out hardware connected to the DCU It lets you turn on or off any of the six lines to test your hardware The sample program FUNCTGEN is good for trying out hardware connected to the analog output line of LabPro It lets you set a voltage level or control the function generator built into LabPro e Study them as examples to learn how to write your own programs The DCUCOUNT program is a very simple program showing how to produce a pattern of outputs from the DCU The program DCUTEMPC is a good example of reading a sensor and then taking action using the DCU based on the sensor reading The program ANOUT is a simple program to show how the analog output line of LabPro is controlled e If none of the DCU programs will do what you need build your program using our subroutines as raw material Start with one of the DCU sample programs Delete the existing code that is not needed Study the sample programs and see how the methods or subVIs are used Carefully study Appendix B to learn what each subroutine does Use these subrou
102. ons to the holes on the socket on the cable This is an easy thing to confuse these are not the pins on the DCU box The End of the Cable that Plugs into the DCU Looking into the Holes The holes labeled 1 2 3 4 5 and 6 are the digital output lines G is for ground and is for the power from the power supply of the DCU We provide one cable to plug into this socket with the lead wires identified for you to use on your first projects To build most projects you will want to make connections to this cable For testing twisting the wires together is probably ok but eventually you will want to solder the leads or make some other connection Whatever you do make sure you insulate the leads so that they cannot accidentally touch each other We recommend using a terminal strip like this one shown below A terminal strip like this is included in the Vernier Robotics amp Control Kit RCK DCU As you build devices to connect to the DCU always keep the power limitations of the DCU in mind For the entire DCU it should not exceed the current limit of your power supply This limit is 300 mA when using the CBL 2 power supply 600 mA when using the LabPro power supply and 1000 mA when using the ULI power supply If you are using a different power supply check the current rating In general you will not damage the DCU by trying to draw too much current but the circuit will not work properly It may also be possible that you could damage the
103. operly Get Resulting Data The last line of our sample program is used to retrieve the data from the LabPro CBL 2 As the first lines of our sample program are executed the LabPro CBL 2 will go about its business of collecting the data Now how do we get the data back to the calculator or computer For NRT data collection the Get command is the answer A Get command will retrieve a complete list of data from the LabPro CBL 2 When using LabPro connected to a computer the data will appear in the serial or USB buffer of the computer after the Get command In computer programs you often need to put a pause in your program code before the Get command to allow time for the data collection to be completed before using a Get command to retrieve the data from the serial or USB port buffer Data Collection in Real Time Mode The discussion above assumes that you want to have a certain number of readings taken at specified intervals for later use by the calculator or computer e g making a graph There is another variation of data collection that is often used We call this real time data collection In this type of program the LabPro CBL 2 takes one reading the calculator or computer retrieves the reading and usually does something with it such as put a point on a graph and then the program loops and repeats This type of data collection is usually done when the number of points collected per second is low 11 Digital Control Unit User s
104. ort cable and clear plastic top On one side of this box is a socket to plug in a DC power supply On the same side is the DCU s short cable which plugs into the Dig Sonic connector on a LabPro or CBL 2 On the opposite side of the box is a 9 pin D sub socket for connecting electronic devices that you build There are connections for all six digital lines plus a power connection and two ground connections We supply a cable with bare wires on one end for you to use in building your first projects You can use the DCU to control as many as six electrical devices The top of the DCU is transparent There are six red LEDs and one green LED visible inside the unit The green LED comes on when the DCU is properly connected and running a DCU program The red LEDs indicate the status of the six output lines of the DCU Power Source Four different power sources can be used e LabPro power supply 6V DC regulated 600 mA Vernier order code IPS in North America different versions are available for use in other parts of the world e CBL2 power supply 6V regulated 300 mA TI Model AC 9201 e ULI power supply 9V unregulated 1000mA Vernier order code ULI PS e Battery power supply one lantern battery or a collection of four to eight 1 5 volt cells in series To make the cable from the batteries to the DCU you need to use a 5 5 mm x 2 1 mm power connector Radio Shack part number 274 1569 Connect the leads so that the center of the connec
105. otation of three motors that can be wired using output pairs 1 2 3 4 and 5 6 59 Digital Control Unit User s Manua DEE ee ew pi x x x x or or cow Controlling Motors connected to DI D2 D3 D4 and D5 D6 CW Clockwise CCW Counterclockwise Note e Ifa third simple motor is connected to D5 and D6 the third motor can be run only when the first two are off but it can be run in either direction Connecting LEGO and Fishertechnik Motors We have used the motors from the LEGO Mindstorms Kit and the Fishertechnik motors with the DCU Both companies make motors that are normally run on 9 volts They will work pretty well connected to a DCU powered by a LabPro power supply 6 volts The advantage of using these motors is that there are lots of gears and pulleys designed for use with them and they have nice systems for mounting the motors LEGO motors are available from PITSCO www pitsco LEGOeducation com Fishertechnik information is at info fischertechnik de Connecting Stepper Motors Stepper motors are very different from simple DC or commutator motors which have two lead wires Stepper motors are used in cases where you want to have exact control of a motion Examples include the positioning of the head on a disk drive or the laser in a CD ROM player There are basically two types of stepper motors that you may want to use unipolar and bipolar You can identify which type you have with this
106. ou Control the DCU Often you will want to read the status of a sensor and use this to decide what the program should do with the DCU For example you may want to check a temperature and turn on a fan motor if the temperature gets too hot Here is a sample program that shows this idea This program is for a DCU controlled alarm system It monitors an analog sensor on channel 1 and sets off a buzzer connected to D1 when the voltage goes over one volt 22 Digital Control Unit User s Manual prgomDCUINIT Initialize the LabPro CBL 2 1 1 1 gt L6 Set up an AutoID sensor in channel 1 Send L6 1 V Sets the limit at 1 unit 0 S Initialize reading from the sensor 3 1 1 0 Le Take a reading Send L6 While S lt V Get S Get the sensor reading until it is equal to or greater than V End 1 D Set output pattern to be used 10 T Set how long the output pattern will be held prgmDCUPWRON Turn on the buzzer Notice this program uses live real time data collection with a 1 in the 3 command When data collection is set up this way you can loop through a section of code and execute a GET statement many times Each time through one reading is taken from the sensor When the conditions to break out of the loop are met the DCUPWRON subprogram is used to turn on the buzzer Taking a Single Reading While Not Collecting Data Sometimes you simply want to take one reading from an analog sensor say to make a decision on what
107. plications Copy this folder to your hard disk in a convenient location e The LabVIEW 6 1 Mac OS9 Runtime Engine must be installed on your computer This installer is included in the Mac OS9 DCU Applications folder The name of the installer is LV6 1 Runtime and Plugin Run it to start the installation e Make sure the extension LabPro USB is installed on your computer This extension comes with the Vernier Logger Pro 2 or Logger Pro 3 program You can find this installer at www vernier com drivers e When all installations are complete the programs can be run one at a time Browse to a program and double click to run Linux Serial connection e The programs and support files are found in the folder called Linux DCU Applications Copy this folder to your hard disk in a convenient location e The LabVIEW 6 1 Linux Runtime Engine must be installed on your computer This installer is included in the Linux DCU Applications folder The name of the installer is labview6l rte 6 1 1 i386 rpm Install as root with the following command rpm Uvh labview6l rte 6 1 1 1386 rpm e Change permissions of serial port s the LabPro will be connected to Users need full access For COM1 chmod 777 dev ttySO For COM2 chmod 777 dev ttyS1 e When all installations are complete the programs can be run one at a time Browse to a program and double click to run Sample Program Descriptions The names of all the DCU programs we have
108. port this programming In fact learning to program LabPro with LabVIEW really boils down to learning how to use a collection of VIs Virtual Instruments supplied on the DCU CD The best way to access these VIs is to find and open a working sample VI Test the sample VI to prove that you have communication with LabPro and that the function such as a digital output works Once you have convinced yourself that your hardware is working then you can take the next step of altering the program to create your own custom program If you will be starting a program from scratch or if you need to add LabPro subVIs or Express VIs to a sample VI there are two good methods to access the VIs 1 Open a sample VI and then highlight and copy the subVIs Express VIs or code you wish to use paste these into the block diagram of your new VI 2 From the Block Diagram open the LabPro palette in your functions palette Functions gt gt All Functions gt gt User Libraries gt gt LabPro to access all of the subVIs and Express VIs Once located simply drag and drop the required subVI or Express VI onto your block diagram A description of what this palette contains is provided later in this section NOTE Installing the folder LabPro in the user lib folder is required to provide access to these VIs in the functions palette 45 Digital Control Unit User s Manua Oe ox Masale Time amp Dialog a geak ae a sll BS gt y IE AEA
109. power supply IPS to the round connector on the DCU 3 Connect a LabPro to the computer using the USB or serial port cable Now navigate to the location on your hard drive where you put the DCU Programs folder and open the folder Inside you will see a number of files Double click on the file named DCUTOGGL vi This will start LabVIEW with the DCU program open You will see the front panel of the LabVIEW program DCUTOGGL vi Front Panel File Edit Operate Tools Browse Window Help DI u 13pt Application Font ESENES e DCUTOGGL This program allows the user to toggle the digital lines Not all possible combinations are allowed The error indicator will light bright red if an illegal combination has been entered Attach DCU to DigSonic CH1 Run the program L 4 Input various LED combinations and watch the DCU PRESS THE LEDs BELOW TO TURN DIGITAL LINES ON OFF DigSonic 1 Front Panel of DCUTOGGL vi 38 Digital Control Unit User s Manual Let s try running this VI Click on the Run button white arrow at the left side of the toolbar This will start the VI running and you should see the green LED of the DCU turn on Problems that might occur are usually solved with the following steps Check your connections Check the power to the LabPro Remove the power from the LabPro and then plug it back in DR Sh If you are using a USB connection look over the Setting Up the Files section above 5 Look over t
110. pper motors Unipolar Stepper Motors Unipolar stepper motors are more difficult to figure out for wiring than bipolar ones Often all the ground wires are the same color or similar colors Use a meter and the trial and error method to figure out the wiring pattern Wire them as shown below 61 Digital Control Unit User s Manua Direct Connection of a Unipolar Stepper Motor The programs for unipolar stepper motor are the same as for bipolar Wired as shown above you can control the unipolar stepper motor using the DCUSTEP or DCUSTEP3 programs There are three different methods of driving a stepper motor Normal Half Step and WaveDrive The DCUSTEP and DCUSTEP3 programs use the Normal method In this case electromagnets inside the stepper motor are always turned on two at a time as the motor steps In the Half Step Method intermediate steps with only one electromagnet on at a time are included This gives you more precision in the positioning of the stepper motor The Wave method of driving a stepper motor has only one electromagnet on at a time For this reason the Wave Drive method uses less electricity but the motor will have less torque Below are the DCU output patterns to use for rotating a stepper motor clockwise and counterclockwise in each of the three drive modes We use the Normal drive method in all our programs but you may want to try the others For Normal Stepper Motor Rotation e 5 9 10 6 for clock
111. provided start with the letters DCU and have eight or fewer letters so that the names match the calculator program names which are limited to eight letters The two analog output programs are named ANOUT and FUNCTGEN On the following page is a list of all sample programs with a short description of what they do Digital Control Unit User s Manua Description of Program Digital Control Unit Programs DCU2 Turns on D1 D6 in succession on DCU connected to DIG Sonic 1 and then turns on D1 D6 in succession on DIG Sonic 2 DCUALARM Waits until Motion Detector detects an object closer than a specified distance Turns on D1 for a few seconds This is a typical program reading a sensor and waiting for an event before the digital output lines are used DCUCAR Allows you to control a car driven by two DC motors using the four arrow keys This program assumes you have a car with a DC motor powering each of the two drive wheels DCUCARS Allows you to control a car driven by two stepper motors and stepper motor ICs using the four arrow keys This program assumes you have two stepper motors controlled by a stepper motor IC driving the two wheels of a car DCUCOUNT This simple program sends each of the 16 possible digital outputs to the DCU lines Counts 0 15 to show the resulting LED displays A very simple program used in several examples in this manual DCUMASS Program to turn on D1 D2 D3 and D4 in order to accelerate a magnet through a
112. quency F and 5 for the number of seconds duration T You add this code to the program by going to the start of the line after where you want to add the new code and pressing 2 INS for insert Then type in the lines You will need to use the ALPHA key to type the letters and the PRGM key selecting from a list of commands to insert the prgm character Refer to your calculator manual if you are not familiar with editing programs Now press 2 and QUIT and run the program again The program should first buzz the speaker at a low frequency for 5 seconds then go through the pattern If you do not have a speaker just look at the 1 LED it should flicker For our final change we want to add to the end of the program We will have the program wait for a key press and then turn on the D1 and D2 lines and leave them on To do this we want to add a Pause command for calculator keyboard input followed by a 2001 3 command to turn on both lines and 2 of the DCU Pause 2001 3 L6 Send L6 20 Digital Control Unit User s Manual The final modified program should look like this prgmDCUINIT 50 gt F 5 gt T prgmDCUBUZZ Disp COUNTING 1 31 17 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 0 L6 Send L6 3 1 17 0 L6 Send L6 Pause 2001 3 L6 Send L6 You now have one example of how a calculator program can control the DCU This example shows how subprograms can be used to make programming easier We encourage you to exp
113. r the least significant bit D2 used for the second digit D3 for the third and D4 as the most significant bit Outputs 0 through 7 give totally independent control of the first three digital lines Outputs 12 through 15 are designed for controlling just D5 and D6 but do not allow any use of the first four lines One reason for this choice is to allow for building robot cars With such a car you might want one wheel to be controlled by D1 and D2 and another to be controlled by D3 and D4 It would still be useful to have some other lines that could be used for other operations Lines D5 and D6 do this but these lines can only be used when lines D1 through D4 are off With this setup you could build a robot that can move around using lines D1 thru D4 and then when it reaches a destination it can do a separate action For example you could turn on a buzzer shoot something or run a third motor Pairs of DCU lines can be used together to allow you to switch the polarity or direction of current flow in an electrical device Consider the circuits on the next page Both circuits show an electrical device wired between the D1 and D2 lines of the DCU The circuit at the left has the D1 set for ds and D2 set for so positive current would flow from D1 through the device and to D2 The circuit on the right has D1 set for and D2 set for ds so positive current would flow from D2 to D1 This idea allows you to have motors run in either of two directions
114. rees apart and so they can be rotated by the motor the program will turn the motor in the direction of the brightest light so the light sensors follow a light source Program that monitors temperature Turns on heater D1 if temperature is below minimum value W and turns on fan D2 if temperature is above maximum value V 71 Appendix B DCUINIT DCUOFF DCUSTEP1 D N DCUINIT DCUOFF DCUINIT DCUOFF DCUINIT DCUOFF DCUINIT DCUOFF Digital Control Unit Appendix B DCUTOGGL L L L3 Program that allows the DCUINIT LA N B W V K T user to toggle the DCUOFF U digital lines with the keypad Note that it takes a second or two for this program to respond to a keypress Also not all possible combinations of outputs are possible so sometimes the program will shut off lines before it turns on a line DCUTRAP2 D T Used in a photogate triggered live trap DCUCHKP Monitors photogate to DCUWAITP detect animal then DCUPWRON D T turns on D1 to take DCUPULSK D action then pulses D2 DCUTRAP3 Another live trap program this one uses DCUSTEP1 D N stepper motors DCUWAITP Monitors photogate DCUCHKP connected to analog DCUOFF channel CH1 to detect animal then activates a directly connected stepper motor to lower a trap door DCUWARNV D T V Warns when the signal gets too high by turning on D1 ANOUT W waveform This is a simple LabPro only F frequency program to show how T period you
115. right places we have written some special code which allows the same LabPro Write command to send data to the LabPro via USB connection So the code we activate when we click the Start button is LabPro Write s 1 31 17 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 0 chr 10 LabPro Write s 3 1 17 0 chr 10 Modifying the Program It s now time to customize the DCUCOUNT program and make it do something different We are going to modify the program to make it go through the counting more slowly but also make two other changes We will modify the program to make it turn on DCU lines 1 and 2 for 3 seconds before it starts the counting sequence Also we will buzz a speaker at 50 Hz for 5 seconds before the pattern starts The speaker hardware is not really required If you don t have a speaker that you can connect to the DCU you will be able to visually check and make sure the program is doing what it should Let s go through the changes one at a time Changing the rate of going through the pattern This is the easy change to make to the code The second number in the 3 command sets the time between steps of an output sequence Change the line so it reads LabPro Write s 3 2 17 0 chr 10 Turn on DCU lines 1 and 2 for 3 seconds before it start the counting sequence Now to turn on the DCU lines we often use a 2001 command The format is 2001 output pattern To turn on DCU lines and 2 we want to send out a 3
116. rns to the DCU So a program that goes through each of the 16 outputs on the DCU would be a program that sends the numbers 0 15 to the LabPro for use by the DCU It sends out a zero at the end to make sure all the lines are off Let s try running this program Select the Run command from the Debug menu at the top of the screen This changes the appearance of the screen You are now seeing the Runtime Environment of REALbasic This is the actual running application with the DCUCOUNT window and its user interface displayed You should see the words LabPro Found written in the ListBox at the bottom of the screen The green LED of the DCU should be on There are no red DCU lights on and the program seems to be waiting for some sort of input from the user Try clicking on the Start button This button starts sending the output sequence to the LabPro It sends each of the possible outputs sequentially holding each output for 1 second Wait for all 17 outputs to cycle through and press the Start button again The sequence should start over again You can continue doing this as many times as you like When you are done press the Stop button This button will cleanly discontinue communication with the LabPro and terminate the execution of the program It will return you to the design view that we saw earlier the Design Environment view of REALbasic Examining the REALbasic Code Since the act of you clicking on the Start button started the sequence of LE
117. rogram is an example It will produce the necessary square wave pattern for most servo motors The easiest way to connect a servo motor is to connect the motor s power line to the DCU connector and the motor s ground lead to ground and the signal line to D1 This is the connection assumed by the DCUSERVO programs You can actually control a servo motor directly from the LabPro or CBL 2 Dig Sonic port without the DCU The reason is that the signal line used to control the servo motor requires very little power Connect the 5V and Ground lines directly to the appropriate pins of the Dig Sonic port and then connect the control line of the servo motor to pin 1 The connections on the Dig Sonic ports are shown below Pin VO1 British Telecom Digital Connector LH Pin2 1 02 Pin3 1 03 Pint Pind PWR 5 3V Pins GND Pin6 1 04 British Telecom Digital BTD Left Hand 63 l Digital Control Unit User s Manual Connecting Devices to the LabPro Analog Out Line The Analog output of LabPro is used by connecting the standard Voltage Probe which comes with the LabPro VP BTA to CH4 This analog output signal can be used for lots of projects but keep in mind the limitation of 4 Volts and 100 mA maximum with a frequency range of 0 5 to 200 Hz Here are some projects we have done using the analog output lines of LabPro These can be done using the speaker lamp and bi color LED that is included in the Vernier Robotics an
118. rogramming Better yet spend some time opening trying out and examining the sample VIs in the DCU VIs folder Try making minor changes and see if they work The best way to learn programming is to actually do it Additional Notes on LabVIEW Programming Additional LabPro Sample Vis The DCU CD contains LabVIEW VIs that are focused on controlling the DCU and analog output lines We have posted additional sample VIs that demonstrate other ways to control the LabPro Visit our web site for more documents and sample VIs at www vernier com labview Collecting Data to Control Outputs Some of the most interesting programs include the use of sensor data for feedback and control Example programs that demonstrate how to collect data from a sensor and then perform a specific digital output based on the sensor reading include DCUALARM DCUSUN DCUTEMPC and DCUWARNV The best way to combine data collection with digital or analog output is to collect the data using the single data point technique This style allows you to go back and forth between collecting data and performing an output relatively seamlessly DCUALARM DCUSUN and DCUTEMPC all use this style The drawback to this technique is that the data collection is slow and data is collected only when asked for not at a defined interval DCUWARNV combines data collection and digital output using the real time RT data collection technique A sampling period is configured for the analog channel whi
119. s sees se ee se es se esse esse ese ee ee ge ee be ee 27 ADDITIONAL NOTES ON REALBASIC PROGRAMMING ee see ese se see ee ee ee ee ee ee ee ee ee ee se ee se ee se ee ee ee Se ke ee ke ee ee 33 USING THE DCU WITH LABVIEW AND A WINDOWS MACINTOSH OR LINUX COMPUTER esse sees sees 37 ADDITIONAL NOTES ON LABVIEW PROGRAMMING ee ese se ese ese se se ese ee ee ee ee ee ee ee se ee be ee se ee ee ee Se Se ke ee Re ee ee 44 CONNECTING DEVICES TO THE DEU ie skeer SeSe bosse bt ta lates eb ee Ee eg oe sees ges Hees ee sed svbees EE EO sege ees Og Gee Sep eters 55 CONNECTING DEVICES TO THE LABPRO ANALOG OUT LINE eee se ee se ee se ee se ee se ese ee ee ese ee ee ge ee ee ee ee 64 DCU gelde SEE EE OE EE ER EE ER ER EE ies 65 APPENDIX A SOURCES OF ELECTRONIC DEVICES ese see se ee se ee se ee ee ee se ee see ee ee ee ee se ee se ee se ee se ee ee ke ee ke ee ke ese ee ee 69 APPENDIX B CALCULATOR PROGRAMS AND SUBPROGRAMS ees sees sees se ee se esse ee se ee ee ee eed Gee Gee Gee ee ee 70 APPENDIX C SELECTED DCU CALCULATOR PROGRAM LISTS ooo sees sees se ee se esse esse ee se ese ee ee ge ee ke ee ee eed eed ee ee 15 The Digital Control Unit Manual is copyrighted 2001 2005 by Vernier Software amp Technology All rights reserved Purchase of the Digital Control Unit and accompanying manual and CD includes a site license entitling the teachers at one school to reproduce the programs source code and manual for use at that one school on
120. s that you are familiar with the use of TI GRAPH LINK or TI Connect for transferring programs from a computer to the calculator If you are not we encourage you to study other manuals and web site information at education ti com or www vernier com for information on this process Organization of This Manual We have tried to organize the manual to allow you to jump around and find information without having to read the entire manual However we do encourage you to read the entire manual except the programming sections that do not relate before jumping into DCU projects The progression of the manual the information and the sections is as follows Learn about how to use the DCU and analog output as a teaching tool view some project ideas and get an overview of the DCU and the analog output driver in the first three sections Introduction DCU Overview and Analog Output Overview The next section The DCU Sample Programs CD provides a description of all of the sample programs included on the CD that come with this manual as well as information about the platforms and programming languages that can be used Use the sample programs for testing your electrical devices for learning how to control the DCU and analog output driver and as the building blocks of your own custom programs Programming is a big part of creating projects with the DCU Regardless of which programming language you use the next four sections are important reference se
121. s this DCU2 I Turns on D1 D6 in DCUINIT LabPro only succession on DCU connected to DIG Sonic 1 and then turns on D1 D6 in succession on DIG Sonic 2 D K T D K N DCUCOUNT Counts 0 15 to show DCUINIT the resulting LED displays DCUMASS Program to turn on D1 DCUINIT D2 D3 and D4 in DCUOFF order to accelerate a magnet through a tube mass driver 70 Digital Control Unit DCUSERVO DCUSTEP DCUSTEP3 P Pulse Width ms N of output patterns in 1 command J loop counter L1 pattern T D N LP DCUSUN X tolerance S T inputs D digital output K Keypress W V S D K DCUTEMPC Controls a servo motor connected to D1 This program works for many servo motors including the one in the Vernier Robotic amp Control kit Simple program that allows user to specify direction and number of steps up to 12 000 for a directly connected stepper motor unipolar or bipolar Change the value of T in the first line to control speed Improved program that directly controls a stepper motor This version is best to use if you plan to use the stepper motor for several different motions one after the other It keeps track of the stepper motor position as it moves This program assumes that you have two auto ID Vernier light sensors connected to CH1 and CH2 and a DC motor connected to the D1 and D2 output lines of the DCU If the two light sensors are mounted pointing a few deg
122. s you to move the robot anywhere you want Also we wanted to have some other lines D5 and D6 which could be used for other operations For example you could have the robot move around until it reaches a position and then use D5 and D6 do something like sound a buzzer raise a flag pick up something etc The program DCUCAR is for this kind of robot A DCU Controlled Robot Using Stepper Motors Two stepper motors can also be used for the two wheels of the robot In general this gives you much better control of the motion of the robot but it will probably be slower to move The program DCUCARS is for use with this kind of robot Note that to control two stepper motors with a single DCU you must use stepper motor control ICs Sensor on a Robot for Feedback Try combining a robot with sensors to provide added control over its motion For example e Mount a Motion Detector on the robot so that it turns and tries a new direction when it gets within a specified distance of an obstacle e Build an edge detector that can tell that the robot has reached the table edge and tell it to stop and back up e Mount Magnetic Field Sensors on the robot so it can navigate using the earth s magnetic field e Mount two light sensors pointed at the tabletop so that the robot can sense whether the tabletop is white reflecting a lot of light or black not reflecting much light Program the robot so that it follows a black line drawn on the table correcting its
123. some sample programs to demonstrate programming for collecting data using just sensors with LabPro no DCU on the CD There is a simple real time live data collection program and non real time data collection program There are versions of these data collection programs in both the Mac Classic and Mac OS X folders REALbasic Developer Articles on using LabPro The July August 2004 issue of REALbasic developer magazine featured a cover story on the use of LabPro in your REALbasic programming The following September October issue continued the discussion on LabPro programming These articles were written by Willam H Murray and Chris H Pappas They offer lots of sample programs and suggestions for writing REALbasic programs for LabPro You can order back issues of this journal at www rbdeveloper com 36 Digital Control Unit User s Manual Using the DCU with LabVIEW and a Windows Macintosh or Linux Computer Introduction This reference guide is to help people who want to use LabVIEW to get their DCU up and running as quickly as possible It assumes that the user has some familiarity with LabVIEW programming The first section covers information on how to run examine and modify one of the sample VIs The next section Additional Notes on LabVIEW Programming provides information about where to look for good examples how to find and use the various Express and subVIs and troubleshooting help This guide is written with the assumption t
124. ss the two connectors of this probe This section will explain how you can control the analog output line in your programs The analog output line is controlled using only the 401 command This one command allows you to set a steady DC voltage output level or to turn on the LabPro s function generator When the function generator is used you can set the waveform amplitude offset and period of the waveform The format of this command is 401 waveform amplitude offset period By changing the parameters you may change the output value The details of setting up the parameters are explained below Note that sine waveforms are very different from other waveforms and they are explained in a special section below Waveform There are 7 possible settings for waveform OFF DC Output Ramp Up Sawtooth Ramp Down Sawtooth Triangle Square Sine Amplitude This is the peak to peak voltage in units of 0 0024 volts except in the case of sine waveforms The practical range is 0 to 1667 This parameter cannot be negative Offset the base voltage relative to ground in units of 0 0012 volts except in the case of sine waveforms The practical range is 0 to 3333 For most simple waveforms and for positive DC voltages just set this to zero Period time in milliseconds to complete one cycle of the waveform The range is 5 to 2000 which corresponds to a range of 200 Hz to 0 5 Hz 17 Digital Control Unit User s Manual In practi
125. st including DCUTEMPLATEStart and DCUTEMPLATEStop These two entries correspond to the Start and Stop button that you see on the window Now notice that the DCUTEMPLATEStart entry is also expanded and we see several Events below it The one that is selected is labeled Action Events contain the code Which executes when the action takes place In this case the code executes when the user clicks on the Start button The syntax of the information that LabPro expects to receive is s command chr 10 The command is just the string of integers we plan to send to the LabPro The s the quotation marks and the curly brackets are required they make sure that the data you want to send out is in a window readable by the LabPro The chr 10 at the end of the line simply adds a termination character to the information being sent out so that the LabPro will know that it has received an entire command We said earlier that we wanted to send out all the possible output codes to the DCU How is that accomplished Earlier sections of this manual explained the commands to control the DCU in this way We first set up the sequence of steps that we want to send to the DCU with a 1 command Then we issue a 3 command for the LabPro to actually start through the sequence of outputs In this case we are using the following command to set up the sequence 1 31 17 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 0 Here the tells the LabPro we are setting up a channel
126. syntax the programming language requires The details that are specific to your programming environment calculator REALbasic LabVIEW will be covered in later sections of this manual Programs for reading analog sensors connected to the LabPro CBL 2 usually follow a pattern like this e Initialize the LabPro CBL 2 a Command 0 is used e Use a Command to set up the channels to which the sensors are connected e Use a Command 3 or a Command 9 to initiate data collection e Get and process the data You will see this pattern repeatedly in the next sections which demonstrate different methods of collecting data from the LabPro CBL 2 The first section demonstrates a non real time data NRT collection program where the data are stored in LabPro until all data have been collected at which time they are retrieved by your program The second section demonstrates real time data collection where a single data point is collected and immediately sent back from the LabPro providing the user with a live look at the data The third section shows how to take a single data point This is very useful in feedback and control circuits The fourth section provides an example program for collecting data from a non auto ID sensor Data Collection in Non Real Time NRT Mode Here is an example of a non real time NRT data collection program which simply means that the data will be stored in LabPro memory until collected by your program This type of data coll
127. system updated fairly recently Specifically operating systems 6 246 and newer support these commands Free operating system updates are available at www vernier com downloads 16 Digital Control Unit User s Manual You can do sequence control of a DCU connected to Dig Sonic 2 by setting up channel 32 instead of 31 as we did for sequence control for a DCU connected to Dig Sonic 1 For example the program below would flash on and off the first three LEDs of a DCU connected to Dig Sonic 2 Call the subroutine DCUINIT intialize Send Out 1 32 2 7 0 set up sequence for DCU connected to DIG Sonic 2 Send Out 3 0 5 8 0 start through the sequence DCU Programming Challenges e Have the DCU red LEDs count in binary from 0 to 11 e Turn on the 5th and 6th LEDs for 10 seconds e Turn on each of the six red LEDs one at a time e Have the DCU turn on the D1 red LED if the temperature of a liquid drops below 30 degrees C e Have the DCU indicate approximate temperature by turning on the appropriate LED to indicate the Celsius temperature to the nearest 10 degrees D1 indicates in 10 to 19 9 degrees D2 indicates 20 to 29 9 degrees etc Programming for Analog Output Control A feature of the LabPro that is not used as often as it should be is the analog output line and its built in function generator The analog output line is accessed by connecting the voltage probe which came with LabPro to the CH4 connector The analog voltage out is acro
128. t an electrical device such as a motor or lamp between the DCU line and a ground connection you can control whether it is on or off using this switch If the switch is in the position current will flow and the device will be on Either of the other two positions will turn it off If you have read the specifications in the documentation which came with the LabPro or CBL 2 you may be Digital Control Unit User s Manual surprised to see that there are six digital output lines on the DCU Each digital port on the LabPro or CBL 2 has only four digital output lines However we do some digital logic tricks which allow us to control six instead of four lines Of course we had to pay a price for this trickery We do not have totally independent control of all six lines We compromised on a pattern that allows us independent control of the first three LEDs and then allows us to use the other three with restrictions The easiest way to see the restrictions is to examine the 16 possible output patterns from the DCU it rth tt de d ek ek i EE i e ia x lt x lt F indicates the line is connected to the positive voltage of the DCU power supply indicates the line is connected to ground negative lead of the DCU power supply and X means the line is disconnected The outputs 0 through 11 can be considered as the binary equivalent of the number with D1 used fo
129. tal Control Unit User s Manual LabPro Write s 1 31 17 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 0 chr 10 LabPro Write s 3 2 17 0 chr 10 End Sub Note that in the DCUBUZZ line the 50 is the frequency that we specified before and the 5 is the duration Now make all these changes to the program and try running it again select Run from the Debug menu If you have a speaker handy connect it between the D1 and Ground lines When you click on the Start button you should see the Ist DCU channel flicker for 5 seconds and if you have a speaker hear a buzz from it Then the LEDs on the DCU should cycle through the 17 outputs more slowly than before Exit REALbasic or open another DCU sample program if you like You may or may not want to save the changes you made You also can save your changed version of the program with a different name This is an example of how you can use the raw material we provide in the window of REALbasic code to create your own DCU control programs REALbasic is an extremely powerful programming tool but like most programming languages you must become familiar with the commands and syntax of the system For more details about LabPro programming refer to the DCU Technical Reference Manual For more information about programming in REALbasic read the manuals that came with REALbasic The best advice we have is to experiment Additional Notes on REALbasic Programming This section offers specific t
130. this are slightly different on various TI graphing calculators On TI 73 TI 83 TI 83 Plus and TI 84 calculators you do this by pressing the PRGM key and then the right arrow to select EDIT and then the ENTER key Scroll down the list of programs until you come to DCUCOUNT and then press ENTER Refer to your calculator manual for information on how to edit the code on other calculators The program should now be listed on the screen Recall that the DCUCOUNT program initially stepped through the sequence one second at a time The 3 command controlled the pace of this process The second number of the 3 command is originally 1 so the steps of the sequence each last 1 second Try moving the cursor to the 1 and changing it to a 2 Then press 2 and then QUIT and run the program again The program should then go through the sequence more slowly Now we want to add a feature to the program by using a subprogram We want it to buzz a speaker before the LED display sequence starts If you have a small speaker available connect the speaker wires between the D1 connection and a Ground connector If you do not have a speaker you can just watch the LEDs and see if the buzzing action is taking place Again display the DCUCOUNT program on the calculator screen Now we need to add the following lines to the program just after the prgmDCUINIT 50 gt F 5 gt T prgmDCUBUZZ These lines will tell the program to execute the subprogram DCUBUZZ using 50 for the fre
131. tines to save yourself work when you can Setting up the Computer Applications for Non Programmers Included on this CD are four computer applications that can be run without having a programming environment installed on your computer If you will be running the programs using LabVIEW REALbasic or Texas Instruments graphing calculators you can ignore the instructions found in this section The information for setting up the files for LabVIEW REALbasic or Texas Instruments graphing calculators can be found later in this manual in the sections devoted to the specific programming environment The four computer applications DCUTOGGL DCUSTEP3 DCUSERVO and FUNCTGEN can be run on Windows Linux Macintosh OS X and Macintosh OS 9 computers following the setup directions below Windows USB or Serial connection e Move the folder called Win DCU Applications to your hard disk in a convenient location e Each of the four programs has its own installer folder Open the folder for the program that you wish to install and double click on the file called setup exe This will start the installation procedure Follow the directions e If you will be using a USB connection you must have the LabPro USB driver installed This driver is automatically installed when you install Logger Pro 3 3 If you do not have Logger Pro 3 3 installed then you must run the LabPro USB installer You can find this installer at www vernier com drivers e When al
132. to D2 Live Traps Activated with a Photogate A fun project is to try to catch flies bugs or mice in a DCU controlled live trap The easiest way to do this is by using a photogate as a sensor to detect when the animal is in position to be captured Photogates have an infrared beam which the animal blocks sending a signal to the LabPro CBL 2 When this happens have the DCU turn on a motor or a stepper motor to move a door to catch the animal We have used a guillotine style door a dropping box or a motor that hits the lid of a hinged box to knock it into place Be creative The program DCUTRAP 2 is an example of a program that uses a DC motor to close a trap The program DCUTRAP3 does a similar thing using a stepper motor to lower a door Alarms Controlled by Motion Detectors Another interesting project is to set up a warning system using a Motion Detector Motion Detectors have a range up to six meters when oriented carefully The program DCUALARM is an example We have used this for sounding a buzzer whenever someone walks in range of the motion detector We have also used it outside with the buzzer inside to detect deer and alert us to look outside so we can see them Note that it is not possible to use motion detectors in conjunction with the DCU on the CBL 2 Activating Camera Shutters Some cameras have connectors so that they can be activated by an electrical signal To get photos of animals in the wild you can use this idea to have
133. to do ina DCU or analog output program The 9 command is the easy way to do this Here is a sample program prgomDCUINIT Initialize the LabPro CBL 2 1 1 1 L6 Set up CH1 for reading an AutoID temperature probe Send L6 Lbl A Label for looping 9 1 L6 Send 9 command Send L6 Get L1 Get value from sensor reading result into a list L1 1 S Take the first number and the list and set egual to the reading Disp S Display the temperature reading on the calculator If S lt 23 Start a loop that will repeat until 23 degrees is reached Goto A End of the loop 2001 1 gt L6 Turn on line 1 Send L6 This program will loop until the temperature reaches 23 degrees and then turn on DCU line 1 Making Sure the LabPro CBL 2 Finishes Its Work before Your Program Moves On One thing that can cause confusion when programming the DCU is when the calculator goes on with its program before the LabPro CBL 2 has time to finish what it is doing This can cause two different types of confusion For example consider this program prgmDCUINIT Initialize the LabPro CBL 2 1 31 2 0 7 gt L6 Set up the digital output to turn the first 3 lines on and off Send L6 3 1 100 0 L6 Go through 100 steps each taking 1 second 23 Digital Control Unit User s Manual Send L6 Disp DONE Display message on calculator when program is finished When you execute a program like this you may be surprised that the calculator indicates
134. tor is negative The voltage supplied can be anything between 5 volts and 12 volts One easy way to build a battery power supply is to use a holder for four C or D batteries in series which will provide about 6 volts Never apply more than 12 volts DC to the DCU Never use AC power supplies with the DCU Note that the center connector on the DCU is negative The total current drawn by everything plugged into DCU should not exceed 600 mA Digital Output Lines The transparent top of the DCU reveals six red LEDs and a green LED The green LED should be on when a program is running and the DCU is properly connected and powered Learn to check the green LED It can warn you if things are not set up correctly and it will keep you from wasting time when they aren t The red LEDs indicate the status of the six digital output lines We refer to the six digital output lines as D1 D2 D3 D4 D5 and D6 You can think of the DCU as a set of six remote controlled switches Each of the six lines from the DCU is connected to a switch that can have any one of three positions ne D1 DCU Connectiono Line ali The line can be connected to the positive side of the DCU power supply to the negative side of the power supply or left unconnected There are six switches of this type inside the DCU Actually they are not mechanical switches but rather electronic switches using transistors that function like the mechanical switch illustrated above If you connec
135. trol allows us to communicate with the LabPro via the Serial Port It is important to the program but you should not have to change anything about it in your projects It does not appear in the program window when you run the application It is only visible in the Design Environment view The serial communications control has a name LabPro It has 29 Digital Control Unit User s Manual properties associated with it and clicking on it will display those properties in the Properties window to the right 3 This is the Properties window It will become more important as you go on with our development of applications Many objects in REALbasic have properties associated with them such as the name caption location etc This window is where these properties are set and changed 4 This is the Tools Window You can drop items from this window onto the main window to add features like buttons labels text windows list boxes and controls We will not be using these controls now but as you program your own applications they will become invaluable 5 This is the Project window of the application It shows all of the other windows that are associated with this program In this program there are a few other windows plus a default Menu window Running the DCUCOUNT Program The DCUCOUNT is a program that we created to count through the 16 possible DCU outputs and then turn all the lines off Each of the numbers 0 15 represents one of the 16 patte
136. ubpalette This program sets up the LabPro for data sampling There are a lot of parameters that can be used with this command but only the first few are given a connector on this subVI The string command that is created in this subVI is s 3 samptime numpoints trigtype trigchchan The inputs to the VI follow Comm port port number of the open port samptime sets time between samples in seconds The possible values are 0 00002 to 16 000 seconds May also be 1 to repeat the previous sampling Numpoints Indicates the number of data points per input to be recorded The possible values are to 12 287 Setting this value to 1 puts LabPro into realtime data collection mode Trigtype Indicates what events must occur on the trigger channel to start sampling default is 0 TrigChan Indicates on which active channel the trigger conditions occur Acton Acton Acton digital Dou Douw EE peig i peil geti idi i Action_Digital Out Located in the Action subpalette Note that there are similar subVIs called Action Digital Lines Off Action_DigOut2011 and Action_DigOut2012 Action Digital Lines Off sends an s 2001 0 command to turn off all lines The 2001 command effects both ports whereas the 2011 and 2012 command only effect the DIG Sonic port and DIG Sonic 2 port respectively This subVI is used to output data to the digital output port during a sampling run One to sixteen data points may be output Sending this command does not
137. ut line of LabPro Appendix C has several of the TI 83 graphing calculator versions of these programs listed line by line so you can examine them l Digital Control Unit User s Manual Programming Overview The next three sections of the manual are a look at low level programming for LabPro CBL 2 The first section Programming for Data Collection will concentrate on collecting data from sensors Reading sensors is very useful in writing DCU and analog output control programs Many interesting projects involve reading a sensor first and then turning on output lines in response The second section Programming for the DCU details writing programs to control the DCU The last section Programming for Analog Output Control provides details for controlling the LabPro analog output line and function generator These three sections are very important to REALbasic programmers and calculator programmers LabVIEW programmers are encouraged to study this information to understand how the LabPro is controlled however many of the subVIs hide this code making it possible to write useful programs without a complete understanding of these sections Two important points to make before jumping into the next three sections are how to send commands to the LabPro CBL 2 and how to properly initialize the LabPro CBL 2 This information is discussed below Sending Commands LabPro and CBL 2 are similar devices and the commands you send to them for co
138. ut you want D and the time you want the pattern held T and all this will be taken care of for you 24 Digital Control Unit User s Manual Reading a Sensor as a Program Goes through a Sequence of Outputs Sometimes you will want to read the status of a sensor at the same time you are stepping through a sequence of output patterns For example you may want to flash a LED or operate a stepper motor while you are monitoring a sensor Here is a sample program that shows how this can be done prgomDCUINIT Initialize the LabPro CBL 2 1 31 4 5 9 10 6 L Set up digital output lines for running a stepper motor Send L6 1 1 1 gt L6 Set up CH1 for reading an AutoID temperature probe Send L6 0 gt T Initialize a variable to represent temperature While T lt 23 Start a loop that will repeat until 23 degrees is reached 3 2 4 0 gt L6 Sample sensor and change the digital output Send L6 Get L4 Get the temperatures mean L4 gt T Calculate the mean temperature Disp T Display the mean temperature reading on the calculator End End of the loop This program will operate a stepper motor or just flash the LEDs on the DCU as it reads temperatures It repeats this until the temperature reaches 23 degrees and then it stops Getting User Input In calculator programs you often want to ask for user input The DCUTEMPC program is a good example It uses the following code to ask the user to enter a temperature
139. want to take a single analog reading check the value and have the program make a decision on how to proceed based on the result A simple example would be a program which turns on a fan connected to the DCU when a miniature greenhouse gets too hot Single point data collection with a 9 command is perfect for situations like that The structure of a program using single point data collection is something like this Send Out 0 initialize LabPro CBL 2 Send Out 1 1 1 set up channel Label A Label this point in the code Send Out 9 1 request single reading Get Resulting Data get data Goto A Loop back to A and repeat Eventually some event such as a key press or a click stops this loop and data collection is stopped Send Out 6 0 stop data collection The channel is set up just as before The 9 Command has the format 9 channel It is repeated each time you want to retrieve one sensor reading from the LabPro If you want to want to read more than one analog sensor set each of them up with a 1 command and read each one with a separate 9 command Calculator programs using a 9 command need to have a Get Command to retrieve the data Computer programs can simply check the serial USB buffer to retrieve the data Data Collection with Non Auto ID Sensors Most analog Vernier sensors are auto ID and are automatically calibrated when used with the LabPro CBL 2 Some older analog Vernier sensors do not have this auto ID feature Also homemade s
140. what the program does ClrHome Set up the calculator screen Disp READY FOR ACTION Display READY FOR ACTION prgmDCUINIT Use the subroutine DCUINIT to initialize the LabPro CBL 2 prgmDCUCHKD Check to see if the photogate is working ClrHome Clear the calculator screen again prgmDCUWAITD Use the subroutine DCUWAITD to monitor the status of the photogate and wait until the photogate is blocked 1 D Set the value of the variable D used to specify which outputs to turn on 1 T Set the value of the variable T used to control the time the output is on prgmDCUPWRON Use the subroutine DCUPWRON to turn on the motor connected to D1 D 1 for 1 second T 1 2 D Set D to 2 because the buzzer is connected to the D2 line prgmDCUPULSK Use the subroutine DCUPULSK to turn on the buzzer connected to D2 and leave it on until a key is pressed Notice that there is not much to the main program All the tricky stuff is done in the subroutines DCUINIT DCUCHKD DCUWAITD DCUPWRON and DCUPULSK Subroutines are used by calling them in the code with the value of certain variables set For example with the DCUPWRON subroutine you call it with D set for the digital output pattern you want on and T set to the time you want the pattern to stay on 26 Digital Control Unit User s Manual Using the DCU with REALbasic and a Macintosh Computer Introduction This reference guide is intended to be used by people who want to get their DCU up and ru
141. wise e 6 10 9 5 for counterclockwise For Half Step Stepper Motor Rotation e 5 1 9 8 10 2 6 4 for clockwise e d4 6 2 10 8 9 1 5 for counterclockwise For Wave Drive Stepper Motor Rotation e 1 8 2 4 for clockwise e 4 2 8 1 for counterclockwise There are other ways to connect stepper motors If you use a stepper motor control integrated circuit IC you will need fewer wires to control the stepper motors This will allow you to control two stepper motors with the DCU One type of stepper motor control IC uses just two lines to control the stepper motor One line is held high or low to indicate the direction the motor should rotate The other line is toggled on and off one time for each step the motor is to move This type of stepper motor control IC is assumed for use with our sample calculator program DCUSTEP2 Other stepper motor control ICs may operate differently 62 l Digital Control Unit User s Manua Servo Motors Servo motors are very popular in robotics because they have a lot of torque for their size and power used Servo motors are controlled by pulse width modulation that is a square wave on off pattern is sent to their control line The length of time that the square wave is at the high voltage is varied to control the servo motor rotor s position The servo motor will hold its position firmly as long as the square wave continues We can create the necessary square waveform from the DCU The DCUSERVO p
142. y controlled by user input e Write a program to produce a steady DC voltage positive or negative controlled by user input 18 Digital Control Unit User s Manual Using the DCU with a Calculator This section is intended to introduce you to how the DCU works with a TI graphing calculator and how it is programmed Skip this section if you are not using a calculator with the DCU You do not need any extra hardware connected to the DCU to work through these examples If you have a small speaker you can use it for one part of this section We try to make things as simple as possible but introduce you to all of the following e Getting the calculator software loaded e Connecting the DCU to LabPro e Running the DCUTOGGL 8 character version of DCU Toggle program to control the DCU lines e Running the simple DCU program DCUCOUNT e Examining and modifying the DCUCOUNT program Follow the steps below to get your DCU operating using the DCUTOGGL and DCUCOUNT programs 1 Load all the programs from the appropriate folder of DCU programs into the calculator using the TI GRAPH LINK cable There are separate folders of DCU sample programs on the CD for TI 73 TI 83 83 84 4 TI 86 TI 92 and TI 92 2 Connect the DCU to the connector on a LabPro labeled DIG Sonic 1 or the connector on the top right side of the CBL 2 labeled DIG Sonic Make sure this connector locks in place 3 Connect a LabPro power supply IPS to the round conne
143. ype of buzzer Other buzzers and simple speakers need to be pulsed that is the power to them must be turned on and off at a high frequency The calculator subprogram DCUBUZZ is an example of this Mass Driver An interesting project to try using electromagnets is to make a device to accelerate magnets Start with a permanent magnet such as a cow magnet Find a clear plastic tube that the magnet will fit through Wrap wire to make four or six electromagnets spaced along the tube Connect the electromagnets to the digital out lines Use a program to turn on the electromagnets in a quick sequence so that the magnet is pulled along Timing is critical The subroutine DCUMASS is an example of this kind of program You may also want to try using three electromagnets that can switch their polarity Some commercial mass drivers operate this way Temperature Controlled Environment Combining sensors with control via the DCU allows you to experiment with feedback Projects of this sort are often educational and interesting Use a temperature probe connected to the LabPro CBL 2 For heating air you can use a small lamp For heating a small amount of water you can use a simple resistor A fan can be wired to move air for cooling The program DCUTEMPC can be used for this type of control It turns on a heater connected to D1 until the temperature reaches a specified reading If the temperature exceeds another specified reading it turns on a fan connected

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