MicroController Software User`s Manual
Contents
1. Background loop while 1 if BITEmode engaged run built in test program if a set of data is ready DataPrint The microcontroller communicates with the laptop computer over a USB data bus Currently there is a single data message transmitted from the microcontroller to the laptop which contains sensor data computed data and various status messages There are several messages which are transmitted from the laptop to the microcontroller there is a command message which tells the microcontroller what to do and there are several configuration and calibration messages which are sent from the laptop at initialization time This function is the USBupdate function that is called every 16 milliseconds It transmits a data message to the laptop every 64 msec and looks for new messages from the laptop every 16 msec Every 64 milliseconds every 4th cycle Load output message buffer with current data USBmsgfill Set message counter for transmission Send message to USB adapter USBsendmsg Read input message USBreadmsg return When the send and read message functions are called there is no assurance that they will be able to complete their tasks in a timely manner The Laptop may have sent only a partial message to the microcontroller or the send buffer of the USB adapter may be full Hence each of these functions has a counter USBsendidx and USBreadidx which keeps track of the amount of data that2. When called the main program is interrupted from its background tasks The real time tasks are all executed and then the program returns to the background loop and continues execution there One important constraint on a real time system is that the real time tasks should all be completed before the next interrupt occurs If not the real time tasks will be interrupted and start again from the beginning When they are completed hopefully on time this cycle the remaining tasks from the last cycle will be completed This can result in data corruption since the completing cycle will not be operating on the same data set as the first part of the cycle which was interrupted This can only be solved with a lot of context switching which creates a lot of trouble in my opinion The easier solution is to ensure that the real time tasks can always complete on time Basically this means that no blocking functions should exist That is any task which can not be completed immediately should be deferred to the next cycle Details The following is an overview of the real time software for the Leaf microcontroller It should help to understand the code of RC c main USB C Communications main initializes everything and then turns on the real time interrupt From then on the items under rtexec get run every 16 384 milliseconds Any time remaining after the rtexec completes is spent in the Background loop of main which will execute the Built in
3. command will work even if the on going command has completed and stopped But the initial distance reference remains the same as the original command 5 Stop causes an on going FwdCmd to halt immediately Only the deceleration rate is specified see word 4 for parameter 5 spare 6 accel command sets maximum acceleration to be used during both acceleration and deceleration Defaults to 300 mm sec 2 if not set zero value Sign does not matter Normally in the range of 50 to 500 7 speed command maximum speed applied to commands 1 and 3 above speed is in millimeters second Robot will accelerate or decelerate to commanded speed at the specified accel rate Sign does not matter Normally in the range 10 to 400 8 9 distance command distance robot should proceed at the commanded speed Robot will automatically come to a stop at the specified distance To move without having a specified distance command a distance which is very far e g 200000000 18 19 20 21 22 Distance command is for forward and for backwards Distance is measured from the last time a FwdCmd 1 was sent If the distance is changed with FwdCmd 3 while a distance is already set the robot will proceed to the new distance the start point will remain where it was originally set Turn Cmd This is an integer number selected a particular mode of steering Turning may be done while the robot is moving forward or stopped If stopped the result is to pi
4. data logging on bit 15 set turn data logging off bit 14 set and the dataset number bits 0 to 7 This integer is processed by ProcessCmds which sets two variables These two variables control the data logging DataLogOn gives the logging status and DataCase specifies the particular data set desired A zero means that data logging is OFF a means that logging has been requested by the laptop DataPrint is the executive for data logging and is called for each processor cycle If it receives a value of 1 for DataLogOn it prints out the appropriate header file and then sets DataLogOn to 2 Ifa 2 is seen DataPrint sends out the appropriate data string The data format consists of a header which identifies all the parameters being recorded followed by a set of data printed each cycle 61 sets per second See DataLog c for an example of the header format and the data print statements Since the data is printed out in background mode only as many parameters can be printed during each frame as can be handled in the time remaining after the real time functions If the print can not be completed before the next real time interrupt it will be completed following the next frame In this event one frames data will be skipped For this reason and others the first data parameter should always be time so that manual and automatic data review can recognize where data has been skipped Most aspects of data logging are con
5. functions in the processor but the above Advance Information manual covers most all of it SRecCvt and documentation Google on SRecCvt or http homepage mac com WebObjects FileSharing woa 65 wo kX5IgoKx0 YHyRPOw 1 0 2 1 2 2 2 31 97 2 35 0 1 1 1 user rbarris amp fpath OSX SRecCvt amp templatefn FileSharing1 html Microcontroller software General Almost all math is performed in fixed point This is because the Motorola chip does not have hardware floating point and the software floating point package is much slower and I am a speed freak One exception is in the Navigation module where I use floating point to calculate X and Y coordinates accurately using triginometric functions Sometimes long ints are used for improved resolution RC C Real time executive Overview A real time system usually consists of a set of code that is executed periodically at a consistent rate This is implemented with a hardware function that calls the real time set of code at a rate based on a hardware clock INITIALIZE As shown to the right the START program first initializes itself and then REAL TIME Fal tees armet starts the real time interrupt The main INTERRUPT program then enters a loop often called the Background loop where it runs forever and may perform useful BACKGROUND REAL TIME computations LOOP FOREVER EXECUTIVE In parallel the hardware real time interrupt will call a defined set of software to execute
6. has been sent or received USBsendmsg transfers the output message to the USB adapter buffer until it indicates full then it returns with USBsendidx set to the amount of data transferred USBupdate will continue to call USBsendmsg each cycle until the counter indicates that the entire message has been transmitted Similarly USBreadmsg returns when the USB input buffer is empty and USBreadidx reports the amount of data received USBupdate will continue to call USBreadmsg until it reports that a complete message has been received At this time it copies the message to another buffer for export to the ProcessCmds function and sets seqnumUSB to the new message sequence number so that ProcessCmds can recognize that a new message has been received This technique avoids the need to wait for USB system to complete message transmissions and avoids exceeding the real time executive frame time ProcessCmds C handle command messages The next highest level function is processing command messages from the Laptop computer and sending those commands to the various microcontroller functions to be executed Each cycle ProcessCmds reads the seqnum of the current input message If it is the same as the seqnum of the last message processed it returns Otherwise it processes the new message note sequence numbers are incremented by the laptop for each message with new content A message with a unique seqnum may be transmitted multiple times Process
7. one if desired Pick a project name Usually Microcontroller for this one Set project options Select Project Options on Paths tab Include path c icc include Library path C icc lib asm and output can be blank on Compiler tab check Accept Extensions only macro define entries can be blank output format is Motorola s19 execute command after successful build should be sreccvt m c0000 fffff 32 lp o out s19 p s19 other entries should be blank on Target tab device configuration should be Custom Program Memory 0x4000 Data Memory 0x1000 Stack Pointer 0x4000 Printf version float nothing else should be checked or filled in note the above target config is for a standard 9S12DP256 with code residing in flash memory The Debug12 utility must be erased at programming time Click set as default then OK Copy all source files into the directory all c and h Go to the Project Add File s option and place all the above source files in the project There is an apparent typo in the hcs12dp256 h file in the ICC INCLUDE folder at least the register name in the include file didn t agree with the processor documentation So change this file as follows This way either spelling works Following line define PWMPRCLC P 0xA3 Add define PWMPRCLK _P 0x43 The file SRecCvt exe must be placed in the ICC folder You can put it elsewhere but you ll have to modify the execute command after successfu
8. Cmds reads the message type identifier in the message and calls the appropriate function to handle that message type Currently there is one message for commands from the laptop to the microcontroller and several messages sent at initialization to configure and calibrate the microcontroller The ProcessCmdMsg function reads motor drive commands and Discrete output commands from the message and calls functions in the motors c module and the DIO c module to set up the specified commands The configuration and calibration messages generally read the message and store the information directly to memory An exception is the ProcessConfigMsg1 function which calls the TimerInit and DIOinit functions These two functions are really part of the basic processor initialization but are not able to be completed until the required configuration information has been received DataLog c Datalog provides the capability of printing out data during every processor frame for analysis or troubleshooting The data is formatted in such a way as to be compatible with the DataPlot utility program A data printout can be requested by a message from the laptop computer The resulting printout can be captured from the RS232 serial bus on the microcontroller at 115K baud to a file using any terminal emulator program A subsequent command message can turn off the printout The data log messages consist of a single integer 2 bytes from the laptop which specify turn
9. Microcontroller Software User s Manual Rev 9 1 05 Comments corrections to Alex Brown rbirac cox net Programming Environment for Microcontroller If you plan to modify the microcontroller code you will need the ICC12 IDE Standard version available from imagegecraft com The Professional version will work but is not necessary The professional version supports paged addressing in the 256K flash memory space The current program uses only 26K and the Standard version can address up to about 40K I don t foresee this program getting this large A 30 day trial version of the IDE can be downloaded from imagecraft The only equipment needed is a desktop PC or laptop with a serial port a USB to serial adapter works The laptop should also have a floppy disk to read store license data a USB floppy works A standard serial cable not a null modem cable is required to go between the PC and the 9 pin serial port on the Adapt9S12DP256 card I will generally provide all the source code in the form of a project folder which contains all the source files and the project setup information However if you have to create a project from scratch use the following directions Project setup Note I always install ICC12 to the default location C ICC I place my project folders in the same directory If you do otherwise you might have to change some things below Create a new project with Project New Select a directory to keep it in make a new
10. e increments per cycle i e 61 per second Reads drive motor quadrature encoders These store to a long integer 32 bits and are implemented in assembly for speed Read the two interrupts for the accelerometer signals Process the reading of the I2C compass signal BITE C Built in test function This tests most input sensors and motor drive outputs over the serial bus connected to a terminal This mode is engaged by selecting ESC on the keyboard when the robot is stopped VECTORS C Sets up all the necessary interrupt vectors IOCHAR C Sends printf bytes to the serial bus COMMAND MESSAGE from laptop Nav and Control to microcontroller revised 8 18 05 Note words are 16 bits 2 bytes Word Value 0 start word currently FFAS 1 time tag Sequential number of command message Unique to each new message with new data Same number should be used on repeated transmissions of same message 2 msg type Message type identifier not used 3 spare 4 FwdCmd this will be an integer value selecting the commanded mode of forward or reverse motion which may be high level e g explore or low level e g forward 1 meter This command is also used to select high level activities 0 None this message has no command for forward motion 1 Proceed straight forward or backwards starting from a stopped condition Starts distance reference at zero see words 3 and 4 for parameters 3 Modify the acceleration velocity or distance of an on going FwdCmd This
11. l build line above The ICC12 IDE generates s19 files which can be bootloaded into an HC12 processor The s19 file generated is not compatible with the paged memory of the 9S12DP256 version The SRecCvt program as directed by the execute command after successful build string converts the generated s19 file to a converted file called out s19 Now you should be able to hit the build project button or select Project Rebuild all and have a successful compilation and generation of an out s19 file that can be loaded into the processor Bootloader First you should have a standard serial cable hooked from the Com port of your PC to the 9 pin connector on the Adapt9S12 I m going to assume your PC communicates on COM 1 for the explanation if it doesn t work you can try COM 2 etc Or look in the Device Manger to see which port you are set to Bring up the ICC12 IDE Go to Tools Environment Options Terminal and set COM Port to COM 1 Baudrate to 9600 Flow Control to None Software S Q also works I believe ASCII transfer protocol to None Hit OK Select Terminal Show Terminal Window this should bring up the blank terminal display Hit the Open Com Port button the button will change to read Close Com Port Switch the RUN PROG switch to the PROG position With 12 vdc power applied to your controller board the green light on the processor should be on Press the reset button on the Adapt9S12DP256 board right upper corne
12. ot will speed up or slow down Acceleration can be modified and will affect any ongoing or future speed changes If the robot cannot achieve the commanded velocity due to motor speed limitations ramps deep rugs etc it will continue at the highest speed it can manage Distance can be changed at any time Direction can even be reversed and the robot will slow to a stop and then proceed toward the new target Even after the robot has completed a forward motion command and come to a stop specifying a new distance with FwdCmd 3 will cause the robot to restart and go to the new target If an explicit stop command has been sent FwdCmd 5 subsequent FwdCmd 3 commands will have no effect You must use a new FwdCmd 1 message to start a new motion Notes Correlation between DIOcmd word and modular jack pins DIOcmd bit 15 no connection 14 no connection 13 no connection 12 no connection 11 DIO2 pin 5 10 DIO2 pin 4 DIO2 pin 3 DIO2 pin 2 DIO1 pin 5 DIO1 pin 4 DIO pin 3 DIO pin 2 DIOO pin 5 DIOO pin 4 DIOO pin 3 DIOO pin 2 OrFNWHBNA gt CO
13. r You should get the following menu page starting D Bug 12 Bootloader If you don t get the bootloader make sure you have moved the Mode Select jumpers on the Adapt board from the 0 to the 1 position Or you might try other COM ports Once you get the menu If there is no cursor on the terminal page click on the page press the a key to erase the flash memory The menu should reappear within 5 seconds Use the browse button to select the out s19 file generated above press the b key to program the flash memory Hit the Download button to actually sent the file A progress indicator on the top will move from left to right This may take a couple minutes When done several rows of asterisks will appear on the screen followed by the menu The program has loaded Place the RUN PROG switch to the RUN position Reset the terminal baud rate to 115K Hit the reset button You should see the words Processor is Running on the screen More may be printed afterwards depending on what is in the program Congratulations are in order I hope Essential documentation Schematic and connector pinout lists usually supplied by Technological Arts with each board purchased MC9S12DP256 Advance Information Google on this and it will find you the motorola website Or just go to http www datasheetcatalog com motorola 75 This document contains all of the programming information Motorola has much more documentation on the various
14. test mode if it is selected or print out data sets to the serial port rtexec real time executive Called by real time clock at 61 hz ProcessCmds processes new commands from laptop if any DIOread reads discrete I O ports I2Ccompass reads Devantech CMPS03 compass via I2C bus Analogs reads in all analog signals Sonar reads all RC ports assigned as sonar inputs RCservo controls all RC ports assigned as RC servos DGyro reads rate gyro and calculates heading Tilto reads accelerometers and calculates accel and attitudes USBupdate reads and transmits USB messages Odometry Calculates wheel travel distances and X Y coords MotorExec Calculates PWM to achieve motion commands Store a dataset if the Background mode has completed printing the previous set Test if operator has selected Built in test mode Set processor clock to 24 MHz Set baudrate to 115K Initialize functions ATDinitQ MotorInit AccelInitQ RGnull I2Cinit Q USBinit Initializes Analog to Digital converters Init c Initializes timers for PWM generation Init c Sets up Port J interrupts for accelerometers Init c Reads rate gyro and calculates average null DG c Initializes I2C bus I2Ccompass c Sets up parallel port to read USB adapter USB c set motor command to stopped set motion complete flags to complete initialize real time interrupt Start real time interrupt causing rtexec above to be called at 61 hz
15. to 7 It cycles through the number of sonars using two cycles to read each RCSERVOS C Radio control servos can use the same output ports as the sonar signals above and are alternatives in software If signals 0 to 3 are sonar then 4 to 6 are defined as RC servos This function generates signals to drive each RC servo to the position commanded by the laptop not implemented yet The command can be to a specific position or to cycle back and forth between two specified positions for scanning of sensors DG C This module is responsible for implementing a directional gyro signal by integrating the yaw rate gyro installed on the microcontroller board It has an RGnull function which is executed at power up and reads 100000 values of the yaw rate gyro to determine an accurate null value Each real time cycle it reads the yaw rate gyro and calculates turn rate and integrates the rate gyro to determine the robot s heading I2CCOMPASS C Reads the current heading from a Devantech CMPS03 compass This is implemented as an interrupt interface hence this function just starts the transaction and the interrupts c module finishes it ACCEL C Reads a dual axis accelerometer chip and makes the results available as filtered acceleration signals and estimates of pitch and roll axis tilt BATTMON C Reads the battery voltage and converts it to volts INTERRUPTS C Provides interrupt handlers for Calling the real time executive and counting time tim
16. trolled by the executive DataPrint noted above However the data is actually written to the Data string for printout in the real time executive rtexec in Microcontroller c so that a data set is always associated with a particular frame A variable called LogFlag is used to ensure that new data is not stored into the Data string until the previous string has completed printing The following are very abbreviated descriptions of the remaining modules They will be elaborated later NAVIGATION C Currently just performs odometry generates wheel speed and distances and some basic dead reckoning calculations MOTORS C This module has three functions all called as MotorExec from the realtime executive Steering calculates differential wheel acceleration speed and distance commands to comply with steering commands sent from the laptop MotorCmd calculates wheel acceleration speed and distance commands to travel forward or reverse as commanded by the laptop The Steering and MotorCmd calculations are summed to generate commands for each of the drive wheels Motor calculates PWM signals for each motor to track to the above commands ANALOGS C Called every cycle to read the current values of the analog input ports and places the results in global memory for use by microcontroller functions none currently and transmission to the laptop for navigation SONAR C Reads up to 7 SRF04 sonar range sensors selectable in software from 0
17. vo 1 29 30 31 same for RC servo 2 32 33 34 same for RC servo 3 35 36 37 same for RC servo 4 38 39 40 same for RC servo 5 41 42 43 same for RC servo 6 44 MCDatalogemd Data logging command word Notes on use of robot motion control commands Forward and reverse motion may be commanded and modified at most any time Motion may be commanded in either the forward or reverse directions The Distance parameter specifies the direction of motion The Acceleration and Velocity maximum parameters apply to both forward and reverse motion and acceleration and deceleration The sign of these two parameters does not affect the results Normally no sign is used A value of distance must be supplied if only to specify direction of motion Normally the robot will accelerate to the maximum specified velocity at the specified acceleration It will travel toward the target distance at the maximum velocity and compute when to decelerate at the specified acceleration to stop at the specified distance If you want the robot to continue travelling for an indefinite distance until you tell it to stop choose a very large value for distance that the robot will never get to A value of 2000000000 2000 KM should do If the robot is traveling forward you can send modified parameters using FwdCmd 3 The robot will continue motion but will transition to the new parameters Maximum velocity can be modified to be larger or smaller and the rob
18. vot in place 0 None no steering command is sent in this message 1 Tum This mode controls direction with respect to wheel encoder data The distance to turn is always with respect to the starting point when the mode is engages see words 9 thru 11 for parameters 3 Modify turn 5 Stop turn note Following commands 10 25 are not yet implemented 10 HdgSel This mode controls direction with respect to the heading signal derived from the yaw rate gyro and compass Heading can be specified from 360 to 360 Robot will turn the shortest direction from the current to new heading see words 9 thru 11 for parameters 13 Modify hdg 15 Stop hdg turn 20 Radius turn 23 Modify radius turn 25 stop radius turn spare Turn Accel turn acceleration rate in deg sec 2 10 normally about 300 Sign doesn t matter Turn rate rate at which robot should turn or pivot in degrees per second 10 Normally in Turn distance DG control DG set Xcoord set Ycoord set DIOcommand range of 50 to 600 Sign doesn t matter how far the robot should turn in degrees 10 30 degrees is 300 is to the right to the left clockwise is to the right If want to turn continuously use a very large number e g 200000000 provisions provisions provisions provisions 23 RCO param0 RC servo 0 rate select 24 RCO param RC servo 0 Left limit command 25 RCO param2 RC servo 0 Right limit mode 26 27 28 same for RC ser
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