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PC Oscilloscope USB based - Introduction

1. Public Property IInputData As Integer Get He Miao PC Oscilloscope USB based 65 Universityof Hertfordshire School of Electronic Communication and Electrical Engineering BEng Final Year Project Report Datareceived 4096 SerialPortl ReadExisting If Me DesignMode False Then RaiseEvent DataUpdatel End If End Get Set ByVal Value As Integer Datareceived 4096 Value End Set End Property Private Sub MainWin DataUpdatel Handles Me DataUpdatel Dim iDataCounter As Integer For iDataCounter USBarray Length 1 To 1 Step 1 USBarray iDataCounter USBarray iDataCounter 1 Next iDataCounter Dim i As Integer For i 1 To 4096 Step I USBarray 0 Datareceived i Next i Me Refresh End Sub Private Sub SerialPortl DataReceived ByVal sender As Object ByVal e As System IO Ports SerialDataReceivedEventArgs Handles SerialPortl DataReceived processing of the recieved data Dim i As Integer Datareceived i SerialPortl Read USBarray 0 4095 For i 1 To 1000 4096 2 Step 1 Datareceived i 256 USBarray i 2 USBarray G 2 1 invert the 8bits to 16 bits Next i End Sub End Class Part 3 using sine function to draw trace support the run interface Public Class Forml Dim Datareceived 1000 As Integer Private Sub UserControlll Load ByVal sender As System Object ByVal e As System EventArgs Handles UserControlll Load End Sub Private Sub Forml Load
2. Afterwards the scaling or average steps of X axis and Y axis were not took into account the programming so that the desired waveform could not achieve Also the control of some key variable like offset was a complicated operation Sometimes it must be defined as globe but maybe brought confusion to the program debugging furthermore some user defined variables conflicted with the control s properties those all needed enough patience and logical ideas to resolve lt gt Another difficulties or improvement are about how to find a useful way to deal with the problem in the communication part the author still keep on working and the inaccurate show value need to be correct as well 4 4 Future development 4 4 1 Extended Advanced functions on oscilloscope simulation X position changes Changing the scales of the X axis and Y axis allows many different signals to be displayed sometimes it is also useful to be able to change the position of the axes This is possible using the X POS and Y POS controls Owing to the limited time only Y POS have developed Figure 44 Y POS vs X POS 11 Y POS 1 moves the whole trace vertically up and down on the screen while X POS moves the whole trace from side to side on the screen These controls are useful because the trace can be moved so that more of the picture appears on the screen or to make measurements easier using the grid which covers the screen for example to measure the period of a
3. Error MessageBoxDefaultButton Buttonl PicAlart BackColor Color Red Exit Sub End Try End Sub Serial Port setting Part 2 reference available at Programming Serial Ports Using Visual Basic 2005 http www devx com dotnet Article 31001 0 page 1 Private Sub OpenSerPort Click ByVal sender As System Object ByVal e As System EventArgs Handles OpenSerPort Click OpenSerialPort End Sub Sub OpenSerialPort If SerialPortl IsOpen False Then Try SerialPortl Open Catch ex As Exception End Try End If InitSerialPort If SerialPortl IsOpen True Then PicAlart BackColor Color Green use the green color to indicate the comport is open Ena IT End Sub Private Sub ClosSerPort Click ByVal sender As System Object ByVal e As System EventArgs Handles ClosSerPort Click CloseSerialPort End Sub Sub CloseSerialPort If SerialPortl IsOpen True Then SerialPortl DiscardInBuffer if the serial port close it should discard the buffer to avoid waste resource SerialPortl DiscardOutBuf fer Try SerialPortl Close Catch ex As Exception End Try End If If SerialPortl IsOpen False Then PicAlart BackColor Color Red End If End Sub Sub Alart Init Q PicAlart BackColor Color Red End Sub Communication programming between USB and PC 1 add the IInputData for communication part 2 update the data array 3 process the received data this part have some problem now should keep on working
4. He Miao PC oscilloscope USB based vi Universityof Hertfordshire School of Electronic Communication and Electrical Engineering BEng Final Year Project Report Fig re 37 ANN 42 Figure 38 Different wave Cos Tunchon nennen nennen nnn nnns 43 Figure 39 ActiveX control reusable nnnnannnnsnnnenennensnnnnsrnrenrnrrrsrrrrnrnrresrnrrrsnrrrsrrrrnnnrrenrrnrnnnrnene 44 SET AIR iMEIRETTE UU M M 44 Figure 41 Show value analysis cccccceeecceceeseeeceeeeeeeceeseeeeeegeeeeeeeeeeseeseeessegeeessegeeeeseeeeeesseeeenens 45 Figure 42 Reusable user controls A 45 Figure 43 Processes display cccscecccccseseeecaeeeeeceeeeeeseaseeeeseeeesseeeeeseeueeesseeeeessegeeeesenseeesseeeeseas 47 Figure 44 Y POS vs X POS mi 48 Figure 45 Function generator Il 49 Figure 46 Dual irace RRRRRR A 49 Figure 47 Block diagram a digital signal processing system 13 sss 49 Figure 48 Basic connections to a DSP board DO 50 Table 1 Cost EE 3 Table 2 Drawline Method Il 8 Table 3 Drawstring Method 6 5i i ues innreda pk uin MAP RPbaRS EEUU EEdEE RETO EU RE 9 He Miao PC oscilloscope USB based vii Universityof Hertfordshire School of Electronic Communication and Electrical Engineering BEng Final Year Project Report GLOSSARY USB Universal Serial Bus DSP Digital Signal Processing Dig
5. a generic introduction on this subject including background information aim and objectives the details of cost analysis and system description have been introduced The following section is a review of the history and background plus the present state of knowledge of the subject area of the project work He Miao PC Oscilloscope USB based Universityof Hertfordshire School of Electronic Communication and Electrical Engineering BEng Final Year Project Report 2 Subject Review PC based oscilloscope PCO Figure 2 Pico Oscilloscope 14 Although most people think of an oscilloscope as a self contained instrument in a box a new type of oscilloscope is emerging that consists of a specialized signal acquisition board which can be an external USB or Parallel port device or an internal add on PCI or ISA card PC Oscilloscopes PCOs are rapidly replacing traditional digital storage oscilloscopes DSOs as the essential item for custom test equipment arsenal The major advantages of PCO are that the display of a traditional oscilloscope is limited by the physical size of the oscilloscope and may only be a single colour With a PC Oscilloscope computer controls the display so not only do user get a full colour display but the display can be the size of user s monitor projector or plasma display Also PC s typically have larger and higher resolution colour displays which can be easier to read Colour can be utilized to d
6. buffer array if the statement serialport read is only used that result in it just read the last received data in array Hence only single data can be read from buffer not a set of data received from USB 2 2 4 Hardware development 2 2 4 a using RS 232 cable to test serial port Refer to the pinout of RS 232 the pin 2 describes the received data and pin 3 describes the transmitted data When using single PC to communication the Female DCE end of the cable should be hanged and then the pin 2 and pin 3 should be connected together that forms a loop to transmit and receive data When the serial port in PC was open and then clicked the send button the data written to the buffer would be send out and then went back to the PC via RS 232 Figure 30 shows the main RS 232 connection for 9 pin connections without hardware handshaking The loopback connections are used to test the RS 232 hardware and software The program on testing part used a loopback on the TD RD lines so that a character sent by the computer will automatically be received into the receiver buffer This set up is useful in testing transmit and receive routines The character to be sent is entered via the keyboard 2 Figure 30 9 pin D type connector loopback He Miao PC Oscilloscope USB based 35 Universityof Hertfordshire School of Electronic Communication and Electrical Engineering BEng Final Year Project Report 2 2 4 b the installation of
7. time div control After finishing the oscilloscope simulation the second objective on developing the required graphical interface like oscilloscope for presenting the graphical data to the user has almost come true So the next part is about the third objective to develop the programming for communication between the USB and PC The flow chart can be designed as following He Miao PC Oscilloscope USB based 31 Universityof Hertfordshire School of Electronic Communication and Electrical Engineering BEng Final Year Project Report Stat Start Afterthe USB port sending l the data to the buffer of PC Read data Read data the SenalPort read EES be from array used to read the received i data from buffer and then Read high byte amp low byte Sm respectively received 256 hig take them into the array ready for plotting However before plotting the received data have to be changed from 6 bits to 16 bits owing to the 16 bits data is desired to plot Moreover the locations hbyte lowbyte of array for plotting are the half of original array hold i received data End Figure 26 USB communication with PC 2 2 2 Integration of the logical sub flowcharts Referring to Figure 27 below additional description should be listed as the following Q COM Port configuration as mentioned in the project design section Figure 9 the programming for realization the serial port
8. Communication and Electrical Engineering BEng Final Year Project Report Chapter 4 Conclusions and future development Chapter overview In chapter 4 the conclusions of project work consist of the difficulties encountered the updated processes the summary of the investigation and the future development improvement and future direction of the current project will be discussed 4 1 Project work summary 4 1 1 Practical outcomes The points below are similarly with the objectives mentioned in the introduction part before lt Anew programming language Visual Basic 2005 has been learnt generally lt gt The user interface has built by using different controls lt How to use ActiveX control to develop the required graphical interface has been implemented lt gt The related data has been plotted in a graphical format lt gt The basic functions of oscilloscope simulation have been developed lt The fundamentals of external interface devices such as RS 232 cable and DLP USB245M User Manual have been understood also their applications have been involved during the processes of this project lt gt Therealization of communication between USB and PCs are developing and the ideas and partial source code have already completed The listed information above is the major findings of the project Obviously there are some improvements and further development which can be carried into execution in the further 4 1 2 Cost and
9. DLP USB245M User manual During this step there are two sub steps should be undertaken LJ USB adapter Powered configuration Q The installation of USB driver The bread board USB cable and DLP USB245M User manual could be used together to carry out the installation As stated in Appendix C the bread board connects components together to build circuits and the leads of most components can be pushed straight into the holes in the board The USB cable could be used as a connector between the USB port and PCs The type B usually connected to the DLP USB245M and the other end A connected to a conventional host hub Figure 11 As shown the pin configuration Figure A 1 the pin 1 amp pin 4 of the cable describes the power supply specification 5V and pin 2 amp pin 3 are for transmitting and receiving data After plugging the USB into bread board the circuit connections to supply power according the Figure below shown had to be completed Figure 21 illustrates a typical USB bus powered configuration A USB Bus Powered device gets its power from the USB bus Basic rules for USB Bus power devices are as follows a On plug in the device must draw no more than 100mA b On USB Suspend the device must draw no more than 500uA C A Bus Powered High Power Device one that draws more than 100mA should use the SLEEP5 pin to keep the current below 100mA on plug in and 500uA on USB suspend d A device that consume
10. LETT LSK S VLISUIPPEYEGI ars Pee ee ee re ee aan bes ur ee ee au m ks ae ee ak dl ss 1 EE RE EE ERE EEE EEE ER EEE EEE ERE EE EE E 1 4 i J HENNE EEG EEE AEE TERRE EAN TREE CE RECEP Pe Ce Ee ER ERR EE EY I b s mimo mm mom mim EEE DE EE m mim mmc m wmm u mm mm m m Wn mom um B aa ee Wa RR ma aa me a Eek HUNE EAE EMEN EE NO MEUME GNU mM WOW W UA M OU HEN ROGA RN ia W RW d LH oe m m a wo af i mim m m m m m m d m ECKE ja ua m HuduumuaEmHMHANEaMA me MEME E mmm y MAZEABREEEDAUEZIHWHUDAARAUMEUBHBEDAZHENMAEARURHEBENARNENHAHASSEEENZUABRSEEMZ mim mm Mm iN Nm A WR MEME mE RUNE Wim m mH UR BC UR Ga R ECK ECK ACA OR NT HE V mmmmmumEENEHEHMN mum mum HRAE Emm va aa Hon BM mm k Aa Ek m j EaaNaNNEBEERBAZIHRESMERREDBSAGZEUASEADEHNZAMNNAZNENEUONHNE ETE DE Leer MEET TE TEEN EEE EEE EEE EEE EEE EE E a L TT SN VAT ENTER EUR UVP RT DENGE FROGS ANANE VINTA TENA E URSIN HB HUSENE Stes eee RB B BEBE BERE EEE EEE PS ETD TT LS TETT YP EY SAPS PL LAN AL AEE RST ED MERE AE ATLE ka PTE TET EP SPT TD aE AT LPT ELLE SISTERE E Figure A 2 Bread Board 1 Each strip forms a node A node is a point in a circuit where two components are connected Connections between different components are formed by putting their legs in a common node On the bread board a node is the row of holes that are connected by the strip of metal undern
11. Mini B plugs and receptacles USB A Male USB B Male Type A left and Type B right USB connectors He Miao PC Oscilloscope USB based 72 Universityof Hertfordshire School of Electronic Communication and Electrical Engineering BEng Final Year Project Report Standard B USB Standard A D D D Zoos Pin Name Cable colour Description gan 1 VCC Gei 45V 2 D White Data 4 3 2 1 er A Dt Green Data D 4 GND Black Ground Pin configuration of the USB connectors Standard A B viewed from face of plug Figure A 1 USB cable The USB specification provides a 5 V supply on a single wire from which connected USB devices may draw power The host operating system typically keeps track of the power requirements of the USB network and may warn the computer s operator when a given segment requires more power than is available The bread board has many strips of metal copper usually which run underneath the board The metal strips are laid out as shown below right These strips connect the holes on the top of the board This makes it easy to connect components together to build circuits To use the bread board the legs of components are placed in the holes The holes are made so that they will hold the component in place Each hole is connected to one of the metal strips running underneath the hole 1 FET LTTE VEN VLR SEAS TELE SEEREN VENER ETA AAAA FP LINJENE WEBEL TELE OL LLFET AREAS TEL PT ARTE
12. PC oscilloscope USB based V Universityof Hertfordshire School of Electronic Communication and Electrical Engineering BEng Final Year Project Report LIST OF FIGURES AND TABLES Figure 1 Project System EE 3 Figure 2 Pico Oscilloscope TA 5 Figure 3 Windows in VB 2008pI91 6 Figure 4 Coordinate System cccccccssccccccssssecececeeseeceeceeeeeeeecaeeeeeeesseaeeceeessaaeeeeeessaeeeeessseseeeeeeaas 7 Figure 5 RS 232 D sub connectors and pin locations for RS 232 connectors 9 12 Figure 6 DLP USB 245M User Manual TO 12 Figure le Eer ge 14 Figure 8 User interface for plotting data 15 Figure 9 5erial POL SENG eierniie neiaie Eni aa EE i era AEI EDEA nai 16 Fig re 10 TAU ANIC ACS MNT m 17 Figure 11 Program structure diagram sese 17 Figure 12 Structure for plotting data 18 Figure 13 Step 1 Update array nennen nennen nnne nnne nnn nnn nnns 18 Figure 14 Update Array explanation cccccccccccsssseceeeceeeeeeeeesseeeeceeeeeeeeeeeeeseeaueeeeesseaeeeesessaaeeeees 19 Figure 15 a step 2 1 draw the border b step 2 2 draw the reference table c step 2 4 plot A M T 4X 20 Figure 16 Real oscilloscope screen left vs stimulant oscilloscope screen right 21 Figure 17 Sub flowchart of step 2 4 A Call fange change Subroutine 23 Figure 18 Sub flow
13. Software part graphics and drawing functionality rerrrrrrrrnnnnrrrrrrnnnnrrrnrrnnnnnrrnvrnnnrrennnnnnn 6 1 1 1 Windows in the Visual Studio 2005 IDEA 6 1 1 2 The coordinate system of Visual Basic 2005 rrrrrrnnnrnvnnnnnrnvnnnnrennnnerennnnenennnnnnrennnnnnen 7 1 13 Graphics ONC lio RRREREORRRRERT mn 7 Ue eae RCV OP COM 0 10 1 2 Communication between software and hardware nnnsnneannneneennnnnsrnnnnesennnnresnnnnreseenenne 10 1 2 1 The PC s Serial Port amp Virtual serial port in VB 2005 eeeessesss 10 VB 11 1 3 Hardware introduction RS 232 Cable amp DLP USB245M User Manual 11 1 3 1 Description of RS 232 cable 11 1 3 2 DLP USB 245M User Manual 12 Chapter 2 Project development and implementation ccseeeeeeceeeeeeeeeeeeeeeeeeeeeeaeeeeeeeeeeeeeaaas 14 2 1 Project overview and JET ae dansere 14 CNN OE mu 14 Ake POS Cl Oe EEE ER 15 22 022 8400 6 510015 160 0 Mc 17 2 2 1 Software development 18 2 2 2 Integration of the logical sub flowcharts rrrrrrrnnnnnrrnrnnnnnnrrnrnnnnnrrnnrnnnnrennnnnnrnrnnnnnnn 32 2 2 3 The function BAGEN REPRE EDO 34 2 2 4 Hardware development nn0annnnnnannnnnnnnnnnnorrnnnnosrnnnrnnnnnrnnonnnrnrenrnrnreosnnnnresnnnerennnnnnee 35 Chapter 3 Testing and debuggmg nennen nennen nnn n
14. can enable applications to work more efficiently by storing data to be sent as the link is available 7 The buffers may be in hardware software or both The serial ports on all but the oldest PCs have 16 byte hardware buffers built into the UARTs In the receive direction this means that the UART can store up to 16 bytes before the software needs to read them In transmit direction the UART can store up to 16 bytes and the UART will take care of the details of transmitting the bytes bit by bit according to the selected protocol 7 When the hardware buffers are not large enough a PC may also use software buffers which are programmable in size and may be as large as system memory permits The port s software driver transfers data between the software and hardware buffers 7 For this project the transferring data must be stressed that in order to achieve maximum throughput application programs should send or receive data using buffers and not individual characters 1 3 Hardware introduction RS 232 Cable amp DLP USB245M User Manual 1 3 1 Description of RS 232 cable HS Recommend Standard 232 is one of the most popular computer interfaces of all time opecifies electrical functional procedural and mechanical aspects of the interface and is designed to handle communications between two devices with a distance limit of 50 to 100 feet depending on the bit rate and cable type Its most common use is to connect to a modem but other
15. cycles the location of m DataPlot 0 would be empty for storing the received data idata Array length Figure 14 Update Array explanation He Miao PC Oscilloscope USB based 19 Universityof Hertfordshire School of Electronic Communication and Electrical Engineering BEng Final Year Project Report lt Text Box show from Figure 8 the design interface on the middle of right side the text control is designed to display the last value idata to the user In that case the user can be aware of the value of received data lt Refresh method refreshes the content of the table This might be necessary after a call to a method when the page does not automatically reflow Step 2 Draw reference table amp plot data This step is divided into four sub steps those are step 2 1 draw the border of region for plotting or reference table step 2 2 draw the divisions used to measure the curve like the background screen of oscilloscope step 2 3 draw texts for showing value and step 2 4 plot data using sine math function Start Start Define the range Define offset of reference e Calculate every Divide the i step or scaling of plotting region by X axis dx 10 A Call Draw lines from range change left to right amp from subroutine End top to bottom 0 B Plot data em Y Figure 15 a step 2 1 Draw the border b step 2 2 Draw divisions c st
16. destination point 6 Oftentimes a Graphics object is obtained by handling a control s Control Paint event and accessing the Graphics property of the System Windows Forms PaintEventArgs class The Paint event is raised when the control is redrawn It passes an instance of PaintEventArgs to the method s that handles the Paint event When programming the PaintEventHandler for controls a graphics object is provided as one of the PaintEventArgs 4 To obtain a reference to a Graphics object from the PaintEventArgs in the Paint event 1 Declare the Graphics object 2 Assign the variable to refer to the Graphics object passed as part of the PaintEventArgs 3 Insert code to paint the form or control 4 He Miao PC Oscilloscope USB based Universityof Hertfordshire School of Electronic Communication and Electrical Engineering BEng Final Year Project Report 1 1 4 ActiveX control The history of Windows Forms Controls has roots in something known as controls Visual Basic Extension VBX This later became more widely known as ActiveX and today revitalized and reborn into the NET Framework it is known as Windows Forms controls There are several good reasons for wanting to create Windows Forms Controls Firstly the same control throughout an application or in lot of different applications can be reusable thus saving on code and the code relating to a control within the control s class can kept for making the code cleaner and
17. device A graphics is associated with a specific device context and many different shapes and lines by using a graphics object can be drawn Before drawing the lines and shapes render text or display and manipulate image a graphics object that represents a GDI drawing surface should be created 4 Therefore there are two steps in working with graphics He Miao PC Oscilloscope USB based University of Hertfordshire School of Electronic Communication and Electrical Engineering BEng Final Year Project Report Creating a graphics object A graphics object can be created in a variety of ways gt Receive a reference to a graphics object as part of the PaintEventArgs in the Paint event of a form or control This is usually how the user obtains a reference to a graphics object when creating painting code for a control gt Call the CreateGraphics method of a control or form to obtain a reference to a Graphics object that represents the drawing surface of that control or form Use this method if the user wants to draw on a form or control that already exists 4 After a graphics object was created using it to draw lines and shapes render text or display and manipulate images Draw line Draws a line connecting the two points specified by the coordinate pairs The common form is like Graphics DrawLine Method Pen Point1 Point2 where the parameters are described in table below Parameter name Function Syst
18. easier to understand 3 A user control is implemented as a class Therefore anything can be achieved with a class it should be also done with a user control that means the user can add properties methods and events to the user control that can be manipulated by whoever is consuming it The user control can have two sorts of properties those that can be manipulated from the properties window at design time and those that have to be programmatically manipulated at run time Hence in certain circumstances it is useful to know whether the user control is in design mode or run mode The control is in design mode is when a form is being designed and the properties of the control are being set it is in run mode when the form is being run and the control is able to expose methods and events For example it is not be appropriate for the control to plot data when the form is being designed but the user will want it to when the application is being run Usually a control itself has a Boolean property called DesignMode which returns true if the control is in design mode and False if it is not 3 1 2 Communication between software and hardware 1 2 1 The PC s Serial Port amp Virtual serial port in VB 2005 All PCs have at least one serial communication port Serial ports have been a part of the PC from the beginning Each COM or Comm communications port in a PC is an asynchronous serial port controlled by a UART A COM port may have the conve
19. increase automatically along with the length of m_DataPlot array increases for drawing sine track Moreover the i is the parameter of m DataPlot thus the m DataPlot i describe the needed data not the address lt Define y1 x2 amp y2 on this condition the offset dx dy were introduced above should be performed together with these variable The y dimension of the current point is calculated ideally yl offset m DataPlot i dy But in the practical debugging some unknown problem occurred if the y1 was defined as above shown the track would always turn over that would discuss in the following chapter Accordingly the y1 is corrected to yl offset m DataPlot i dy Likewise the next coordinates is defined as x2 71 1 dx x1 70 y2 offset m_DataPlot i 1 dy The offset is to assure the begging point is at the middle of the reference table so all coordinates points are plotted according to the offset If the offset changes the position of the curve will be altered as well By multiplying the dx and dy the sine Curve can be zoomed in and zoomed out automatically as the size of screen changes Assuming the dx or dy are not used the curve will be only straight line in the x axis or y axis lt Restrict the sine wave in the plotting region note Y1 amp y2 stands for y1 amp y2 belong to the plot region When the sine wave is zoomed in the trace m
20. market needs Based on costing in the Introduction and brief description about PC oscilloscope in Subject Overview the components or small items of equipment and necessary software package for this project were nearly available in the University So the project budget within the maximum available budget 50 The PCO is the modern alternative to traditional bench top oscilloscopes that will be more popular as the development of software Moreover the PC can supply higher resolution and different colour for individual trace that bring a convenient and comprehensible way to observe or analyze required trace Additionally since prices can range from as little as 100 to as much as 2000 depending on their capabilities it is commonly acceptant tool He Miao PC Oscilloscope USB based 46 Universityof Hertfordshire School of Electronic Communication and Electrical Engineering BEng Final Year Project Report 4 1 3 Report conclusion This report introduced the statement of the background of the subject the reasons for undertaking the work the aim and objectives and the methods employed to achieve these objectives at the beginning It also contained the descriptions and explanations of project implementation throughout the period of project work with the help of flow charts What is more the test results were shown using diagrams together with essential discussion In the end the future direction of the current project was d
21. subroutine is not called The description on rescaling size Only at the design mode the control in the run interface named usercontrol11 Figure 10 can be rescaled the size and ideally the control size can be changed to any standard But the size has to be specified a minimum value logically for all the controls can be visible in the screen Since there are many controls need to be defined the position according to the size of usercontrol11 that can be found by using the resize event which indicates using the width or height property can set the window width and height independently On this condition a reference position such as the position of PicDataView Figure 8 should be defined by the width and height of the usercontrol11 first And then the position of another controls added in the usercontrol11 can be defined based on the PicDataView When it comes to altering the position of the sine wave the flow charts in next page indicate that it goes down and goes up separately Adjusting Y POS allows the zero level on the Y axis to be changed moving the whole trace up or down on the screen to give an effective display of signals like pulse waveforms while do not alternate between positive and negative values of x axis He Miao PC Oscilloscope USB based 29 Universityof Hertfordshire School of Electronic Communication and Electrical Engineering BEng Final Year Project Report Call downdata o
22. the device drivers for the DLP USB245M board The next time the DLP USB245M module is attached the host PC will immediately load the correct drivers without any prompting 4 Run the serializer program and write the VID 0403 PID 6001 a description string of the users choosing and manufacturers ID as instructed in the instruction manual that was downloaded with the serializer software Terminate the serializer program and disconnect the DLP USB245M board from the USB cable Wait 10 seconds and reconnect the DLP USB245M board Reboot the PC if instructed to do so 10 After installing the driver under the Device Manager of PCs the USB serial port COM port and USB serial converter would appear automatically That means the USB driver can retrieve COM ports from the system and automate the selection of COM port to the height available The USB serial port also can be said as Virtual COM ports that is a link between the programming language or software development and USB module Summary This chapter introduced the project implementation consists of programme development and USB port installation The previous one utilized several logic flow chats to describe how to plot data and how to realize the oscilloscope simulation As for hardware development mostly referred to the data sheet of the DLP USB 245M user manual to perform how to plug the USB into PCs Indubitably the following chapter should lay out the testing results together
23. the programmers have to pay attention to the control of position and some related parameter changes of these two trace Figure 46 Figure 46 Dual trace Certainly other left controls in the oscilloscope can be added as well 4 4 2 USB connectivity between PC amp DSP Analogue A D Digital signal D A Input signal Converter digital input Processor digit converter output signal signal output signal Figure 47 Block diagram a digital signal processing system 13 He Miao PC Oscilloscope USB based 49 Universityof Hertfordshire School of Electronic Communication and Electrical Engineering BEng Final Year Project Report Most of the signals encountered in science and engineering are analogue in nature That is the signals are functions of a continuous variable such as time or space and usually take on values in a continuous range Such signals may be processed directly by appropriate systems Digital signal processing provides an alternative method for processing the analogue signal as illustrated in Figure 47 To perform the processing digitally there is a need for an interface between the analogue signal and the digital processor This interface is called an analogue to digital A D converter The output of the A D converter is a digital signal that is appropriate as an input to the digital processor The digital signal processor may be a large programmable digital computer or a small microprocessor programmed t
24. with required explanation He Miao PC Oscilloscope USB based 37 University of Hertfordshire i EI School of Electronic Communication and Electrical Engineering BEng Final Year Project Report Chapter 3 Testing and debugging Chapter overview After discussing the project design and implementation together with the analysis of function judgement this chapter will present the testing results including the tack and oscilloscope functions shown and different waves display using some common math models Also error analysis depends on the results shown will be involved 3 1 Test result HE PlottingData Fin w jJ Figure 32 Representation of data graphically Using sine function with proper parameters defined such as amplitude and period the correct sine wave was drawn on the plotting region PicDataView The texts in the screen were designed to measure amplitude position and time of the curve The offset had emphasized before was working as expected The graph was restricted to draw from the vertical midpoint that made it looked like more symmetrical and convenient to scale The last value displayed the last data in array abstractly In addition the parameter in the sine function must be defined larger than the locations of array If it is only the half of the locations the half of the sine wave will appear that results in waste of room Adding two controls in user interface is a convenient way to analy
25. 29 He Miao PC Oscilloscope USB based 69 Universityof Hertfordshire School of Electronic Communication and Electrical Engineering BEng Final Year Project Report APPENDICE B Hardware DLP USB 245M Adapter Available at data sheet of USB module reference 11 Pin number and description Table 1 DLP USB245M PINOUT DESCRIPTION Description BOARD ID Out Identifies the board as either a DLP USB245M or DLP USB232M High for DLP USB232M and low for DLP USB245M RESET In Can be used by an external device to reset the FT245BM If not required this pin must be tied to VCC RESETOX Out Output of the internal Reset Generator Stays high impedance for 2ms after VCC 3 5v and the internal clock starts up then clamps it s output to the 3 3v output of the internal regulator Taking RESET low will also force RSTOUT to go high impedance RSTOUT is NOT affected by a USB Bus Reset 3V3OUT Out Output from the integrated L D O regulator It s primary purpose is to provide the internal 3 3v supply to the USB transceiver cell and the RSTOUT pin A small amount of current lt 5mA can be drawn from this pin to power external 3 3v logic if required SLEEP Out Goes Low after the device is configured via USB then high during USB suspend Can be used to control power to external logic using a P Channel Logic Level MOSFET switch SND WUP In If the DLP USB245M is in USB suspend a positive edge on this pin W
26. AKEUP initiates a remote wakeup sequence If the device is active not in suspend a positive edge on this pin SEND causes the data in the write buffer to be sent to the PC on the next USB Data In request regardless of how many bytes are in the buffer He Miao PC Oscilloscope USB based 70 Universityof Hertfordshire School of Electronic Communication and Electrical Engineering BEng Final Year Project Report VCC IO In 3 0 volt to 5 25 volt VCC to the UART interface pins 10 12 14 16 and When interfacing with 3 3v external logic connect VCC IO to the 3 3v supply of the external logic otherwise connect to VCC to drive out at 5v CMOS level This pin must be connected to VCC from the target electronics or EXTVCC EXTVCC In Use for applying main power 4 4 to 5 25 Volts to the module Connect to PORTVCC if module is to be powered by the USB port typical configuration PORTVCC Out Power from USB port Connect to EXTVCC if module is to be powered by the USB port typical configuration 500mA maximum current available to USB adapter and target electronics if USB device is configured for high power RXF Out When low at least 1 byte is present in the FIFO s 128 byte receive buffer and is ready to be read with RD RXF goes high when the receive buffer is empty TXE When high the FIFO s 385 byte transmit buffer is full or busy storing the last byte written Do not attempt to write data to the transmit buffer
27. BACHELOR OF ENGINEERING DEGREE DEGREE WITH HONOURS IN ELECTRONIC AND COMMUNICATIONS ENGINEERING Final Year Project Report ochool of Electronic Communication and Electrical Engineering University of Hertfordshire PC Oscilloscope USB based Heport by HE MIAO Supervisor Georgios Pissanidis Date April 2008 DECLARATION STATEMENT certify that the work submitted is my own and that any material derived or quoted from the published or unpublished work of other persons has been duly acknowledged ref UPR AS C 6 1 Appendix Section 2 Section on cheating and plagiarism Student Full Name He Miao Student Registration Number 06130352 elei EEE EN NN Date 07 April 2008 University of Hertfordshire School of Electronic Communication and Electrical Engineering BEng Final Year Project Report ABSTRACT This report describes a comprehensible method to evaluate desired data in a graphical format that is a preferable and common way in the communication world The discussion and implementation on PC oscilloscope simulation of the graphical data are also involved which should help reader to have a full and further understanding on this subject Using a top level structure diagram flow chart to introduce the processes of project is a legible and informative manner Also in this report the aspects and principle of related productions such as USB port amp RS 232 cable is presented In the end the test results
28. ByVal sender As System Object ByVal e As System EventArgs Handles MyBase Load UserControlll PicGraph color Color BlueViolet UserControlll PicGraph Line Color White Dim t As Integer For t 1 To 1000 t must be greater or equal to the plotting location Datareceived t 500 Math Sin Math PI t 250 250 means there should be ploted two cycles in the screen 500 stands for one cycle Next For t 1 To 1000 UserControlll data Datareceived t Next t End Sub He Miao PC Oscilloscope USB based 66 University of Hertfordshire School of Electronic Communication and Electrical Engineering End Class Test results Different traces 1 Truncate 2 Sort 3 Round He Miao PC Oscilloscope USB based 67 BEng Final Year Project Report Send Data Zoom eut meme JG ben mn 1772 Send Data University of Hertfordshire School of Electronic Communication and Electrical Engineering BEng Final Year Project Report IU PTT TTT TT SI EISES ES TITT rid Hi meddelelse Fosition Amplitude Es S ES E EE E S ES Zoom In Ce A ATA TT LI TT 40008 TOLL LL Active X control reusable in the run interface Amplitude Amplitude fe EB ERU TRE HC IL DER NT ENNEN zz TL Zen er Tine SITTET FC i ET JIA TT NTT DrawCurvet DrawCurve Ela Position Position Cs J pe jJ CEE EEE Last value
29. DERE AANE Last value p FF Amplitude I EES DR eebe es E Amplitude TES TE ER SERT EI IWER ERE ERR EE FANS RET EE Time TER E E T ER ERR RR RR Time tt pM pM E DE EAT LN BERE IR RE ERES a Ee E We E EU Position BENE SEESIPERSE RER ae Position LJ LE G re PUAN FR LAN BEEN RR D ER DA ES SSRS B EBEN Last value EE RR ER ERE RR ERR ei Last value He Miao PC Oscilloscope USB based 68 University of Hertfordshire School of Electronic Communication and Electrical Engineering BEng Final Year Project Report The program structure for plotting data Plotdata using sine math funtion Define offset Calculate the every step of x axis dx Draw region ics for plotting g m class gr Call the Define the scaling of y amount of data axis to subroutine display m_range Draw the border of table The size of display window of y axis Plot the Define the m screen range divisions of range of the table reference table dy mgscreen Divide the _range m_ra nge plot region g by 10 Draw lines from left to right amp from top to bottom Data plot Draw text yi amp y2 belong to the plot region Define t as Limit y1 amp y2 counter in the region Add usercontrol1 to form of plotting data UserControl1 1 data Mace with a trial Copy of ergi Ur Buy SmartDraw purchased copies print this document without a watermark Visit www smartdraw com or call 1 800 768 37
30. DataView Top 5 PicDataView Left 5 PicDataView Width Me Width 200 PicDataView Height Me Height 25 Me Refresh Labell Top 35 Labell Left PicDataView Width 27 Labell Width 59 Labell Height 12 MaxValue Top 26 MaxValue Left PicDataView Width 100 MaxValue Width 75 MaxValue Height 21 ShowMax Top 57 ShowMax Left PicDataView Width 20 ShowMax Width 75 ShowMax Height 20 ShowMin Top 57 ShowMin Left PicDataView Width 100 ShowMin Width 75 ShowMin Height 20 Label2 Top 97 Label2 Left PicDataView Width 27 Label2 Width 29 Label2 Height 12 ShowTime Top 88 ShowTime Left PicDataView Width 100 ShowTime Width 75 ShowTime Height 21 DrawData Top 115 DrawData Left PicDataView Width 20 DrawData Width 75 DrawData Height 20 Button4 Top 115 He Miao PC Oscilloscope USB based 56 Universityof Hertfordshire School of Electronic Communication and Electrical Engineering BEng Final Year Project Report Button4 Left PicDataView Width 100 Button4 Width 75 Button4 Height 20 Label3 Top 154 Label3 Left PicDataView Width 27 Label3 Width 53 Label3 Height 12 TextBox3 Top 145 TextBox3 Left PicDataView Width 100 TextBox3 Width 75 TextBox3 Height 21 upbutton Top 172 upbutton Left PicDataView Width 20 upbutton Width 75 upbutton Height 20 DownButton Top 172 DownButt
31. Dim xl x2 yl y2 As Integer Offset m endY high 7 2t 20 dx CDbl widthl m DataPlot Length 1 the scaling of x or every step of x axis only utilize the dx amp dy the sine curve can be zoom in and zoom out as the size of screen changes This is the data are plotted on the screen current value xl yl next value x2 y2 xl m startX 70 define the current value of x For i 0 To m DataPlot Length 2 Step 1 yl offset m DataPlot i dy define the current value of y x2 m startX 71 i dx define the next value y2 offset m DataPlot i 1 dy If yl gt m endY 20 Then yl m endY 20 If yl lt m startY 5 Then yl m startY 5 If y2 gt m endY 20 Then y2 m endY 20 If y2 lt m startY 5 Then y2 m startY 5 In order to guarantee the value of y that beyond the reference table range when the curve zoom in can not be shown in He Miao PC Oscilloscope USB based 60 Universityof Hertfordshire School of Electronic Communication and Electrical Engineering BEng Final Year Project Report the screen gr DrawLine Pens White xl yl x2 y2 xl x2 Next i End Sub Sub range change define the data and show the current value m range m MaxValue m MinValue the amount of data wanted to show currently in the y axis m screen range m endY m startY 25 the range of display window in y axis the display region in the window of data display dy m screen ra
32. EI III Fal See When added two controls in the run interface from figure left there was TTT TTT T TT just waveform no other controls anymore although the size rescaling TT had adjusted Back to Figure 39 that ATI N TT 2 IALT was an updated design interface ATA over readjusting the controls size FM FARM and position this was not an TTY yA EG ERE expected step The improvement is ATA TL TAL IME that the programming on recalling PINT TN TE size has to be correct Maybe more than one reference positions should Herren TT be utilized to define the controls ITIL CATE positions and size Figure 42 Reusable user controls 3 2 3 Serial port test When using the RS 232 cable to test port oftentimes the send button had to be clicked twice that only enable the transmitted data can be received Maybe the reason is that there is some delay occurred when the data is transmitting over the cable or the Baudrate is set to 9600 therefore assuming 12345678 is sent the speed of transmitting should be 8 1 9600 8 33e which is too fast to catch up Summary This chapter described the results of the programme debugging along with comments Also the possible reasons and recommendations for arisen errors were discussed The last chapter below will provide a concise summary of the major finding and outcomes of the report He Miao PC Oscilloscope USB based 45 Universityof Hertfordshire School of Electronic
33. Items Add 1200 CombBaudRat Items Add 2400 CombBaudRat Items Add 4800 CombBaudRat Items Add 9600 at 9600bps a bit is 0 1 millisecond CombBaudRat Items Add 19200 CombBaudRat Items Add 38400 CombBaudRat Text 9600 the initialization of the parity CombParity Items Add NONE CombParity Items Add ODD CombParity Items Add EVEN CombParity Text NONE the initialization of the databits CombDataBits Items Add 5 CombDataBits Items Add 6 CombDataBits Items Add 7 CombDataBits Items Add 8 CombDataBits Text 8 the initialization of the stopbits CombStopBits Items Add 1 CombStopBits Items Add 2 CombStopBits Text 1 End Sub Sub InitSerialPort With SerialPortl Try Select Case CombSerPort Text the select of COM Case COMI If PortName lt gt COM1 Then CloseQ PortName COMI Open Else Exit Select End If Case COM2 If PortName lt gt COM2 Then Close PortName COM2 Open Q Else Exit Select End If Case COM3 If PortName lt gt COM3 Then CloseQ PortName COM3 He Miao PC Oscilloscope USB based 63 Universityof Hertfordshire School of Electronic Communication and Electrical Engineering BEng Final Year Project Report Open Else Exit Select End If End Select Catch ex As Exception MessageBox Show The COM is not existing or occupying error MessageBoxB
34. Manual and RS 232 cable 1 1 Software part graphics and drawing functionality 1 1 1 Windows in the Visual Studio 2005 IDE GE WindowsA pplicationl Microsoft Visual Basic 2005 Express Edition File Edit View Project Build Debug Data Tools Window Community Help ES et LL 3 22 al n rz ax 59 dl ely AR E b i SS 5 s e a Ca Toolbox e 41x f Foral vb Design Start Page X Solution Explorer x All Tindows Forms Si a z E ES Common Controls he Point Ka TindowsA pplicationl Es sd My Project Button ES Forml vb CheckBox EZ CheckedLi stBox EN ComboBox TA DateTimePicker A Label A LinkLabel 2 ListBox 25 ListView amp MaskedTextBox F MonthCalendar NotifyIcon y Solution Explorer 4j Dsta Sources 12 NumericUpDown gl Properties x aa PictureBox T xy w Formal System Windows Forms Form X HM ProgressBar RadioButton Dz SS RichTextBox Padding 0 0 0 0 abl TextBox RightToLeft No bk ToolTip Ri ghtToLeftLayout False TreeVi ShowIcon True 3 TreeView ca ShowInTaskbar True Ed WebBrowser Size 491 430 Containers SizeGripStyle Auto i Genes amp Toolbars StartPosition WindowsDefaultLocati o Data Tag E Components FE F 1 ex orm Printing wi ee TopMost False NG General Text The text associated with the control There are no usable v lt gt Ready Figure 3 Windows in VB 2005 3 Toolbox the toolbox contains reu
35. Windows Programming 1999 Addison Wesley ISBN ISSN 0201178184 Chapter 15 184 190 3 Willis Thearon Beginning Visual Basic 2005 Thearon Willis and Bryan Newsome 2005 Wiley Pub IBSN 0764574019 Chapter 1 pp 2 amp pp11 Chapter 13 pp400 amp pp411 Chapter 14 pp 428 433 4 Title Windows Forms Programming How to Create Graphics Objects for drawing internet Available at URL http msdn2 microsoft com en us library 5y289054 aspx Accessed December 2007 5 Title NET Framework Class Library Graphics DrawLine Method Pen Point Point internet Available at URL http msdn2 microsoft com en us library f956fzw1 aspx Accessed November 2007 6 Title NET Framework Class Library Graphics DrawString Method String Font Brush PointF internet Available at URL http msdn2 microsoft com en us library 76c5db29 aspx Accessed December 2007 7 Axelson Jan Serial port complete programming and circuits for RS 232 and RS 485 links and networks c2000 Lakeview Research Chapter 3 pp25 Chapter 2 pp21 Chapter 6 pp117 8 Title NET Framework Class Library SerialPort Class internet Available at URL http msdn2 microsoft com en us library system io ports serialport aspx Accessed 17 March 2008 9 Title Data Link Communications Interface and Control Solutions RS232 Pinouts internet Available at URL http www datalinkcom net rs232 pinouts html Accessed 20 March 2008 10 Title DLP desi
36. along with essential explanations are included as well He Miao PC oscilloscope USB based i University of Hertfordshire School of Electronic Communication and Electrical Engineering BEng Final Year Project Report ACKNOWLEDGEMENTS Firstly I would like to express my thanks to my project supervisor Dr Georgios Pissanidis for his patience and intelligible guidance throughout this project Also I hope to thank Talib Alukaidey and Johann Siau for their useful advices Finally I wish to thank my friends for their precious encourage helping me to combat difficulties during project He Miao PC oscilloscope USB based iii University of Hertfordshire School of Electronic Communication and Electrical Engineering BEng Final Year Project Report TABLE OF CONTENTS DECLARA HON STATEMENT c E STE WEE i ACKNOWLEDGEMENTS c eee iii jio CONTENT iv EIST OP FIGURES AND E EE vi teo viii Des Move 1 1 1 Backgro nd RER ES EN 1 1 2 Motivation and challenges rrrrrrnnnnnrnnrrnnnnrrvnrnnnnnnrnnrnnnnnsennnnnnnnsennnnnnsrsennnnnnsssrnnnnnnsseennnnn 2 n En Le Ballet Ee 3 E E SIC Me SC lOO ln E 3 NN 4 Le Rs DO ge ENN 4 e Ee REVIEW eoaersiiirnesriionesa iisen diania aiae ia naiiai irada irada didisain 5 3 Description OF Project te 6 Chapter 1 Technical theory m 6 1 1
37. ange or Height m range Figure 17 Sub flowchart of step 2 4 A Call range change subroutine 2 4B Plot data 2 4 B Plot data for loop 0 to m_DataPlot length 1 Define current coordinates point x1 m startx 70 Define y1 x2 amp y2 Use for loop Restrict the sine wave in the plotting Draw data using region sine function in run interface Use gr drawline x1 x2 y1 y2 End Figure 18 Sub flowchart of step 2 4 B plot data He Miao PC Oscilloscope USB based 23 Universityof Hertfordshire i EI School of Electronic Communication and Electrical Engineering BEng Final Year Project Report The explanation on 2 4 B plot data in Figure 18 There are three primary steps for plotting data First of all the x dimension x1 of the current coordinates point should be defined outside the for loop Secondly using for loop is to realize the circle for drawing sine wave Besides at the Form Designer for plotting data Figure 10 the data should be plotted The exposition on 2 4 B plot data for loop lt iz0to m DataPlot length 1 the i is defined as a counter and adding 1 as the loop cycles every time so that it can be utilized to execute together with the y dimension y1 of the current coordinates point and the following coordinates point x2 y2 owing to the distance or displacement of x axis and y axis should
38. arameter for other components Draw the border of plotting region The reference table or the background screen of oscilloscope is utilized to measure the amplitude time or the position of the track has plotted on the canvas The text is drawn which is prawan used to show value clearly reference table divisions Draw text The screen as a two dimensional graph of one or more Plot data using electrical potential differences vertical axis plotted as sine math Ise uon a function of time or of some other voltage horizontal v axis End Figure 20 Integration of each part for step 2 Every related part for plotting data and drawing the reference table can be encapsulated into an independent subroutine named DrawData for example that will be make the program work efficiently and conveniently to call in the oscilloscope simulation section And because of the programming for Windows is commonly known as event driven programming the subroutine DrawData must be called in the paint event which is provided by the control itself and raised when the control is redrawn Also the data to be plotted should be happened in the run mode not the design mode He Miao PC Oscilloscope USB based 26 University of Hertfordshire School of Electronic Communication and Electrical Engineering BEng Final Year Project Report The virtual serial port that is provided by the Visual Basic 2005 is used to per
39. ation and Electrical Engineering BEng Final Year Project Report 2 2 1 Software development Building a user interface using Windows Forms or Windows Controls is all about responding to events so programming for Windows opened up the world of event driven programming Events in this context include for example clicking a button resizing a window or changing an entry in a text box The code that the programmers write responds to these events Plot data Step 1 Step 2 Draw reference table amp plot data Yes Step 2 1 Step 2 2 Step 2 3 Step 2 4 Draw divisions Draw text Plot data Figure 12 Structure for plotting data Draw border of table The key task for software development is on plotting data First of all adding a new property to the control is necessary to tell the control when to plot data instead of the globe variable due to some ineluctable confusion always happened when debugging software Moreover that is a fairly common requirement in writing software is the ability to hold lists of related data This functionality can be provided by using an array and it is just lists of data that have a single data type When data is coming the array should be ready for receiving the data and updating simultaneously owing to the received data is different From Figure 12 four sub steps come under the step2 which are main embranchments for completing to draw the track representation of desired data with reference table or screen in o
40. axValue PicDataView Refresh do not want the changable values covered each other DrawData He Miao PC Oscilloscope USB based 58 Universityof Hertfordshire School of Electronic Communication and Electrical Engineering BEng Final Year Project Report End Sub in fact real function of time div is changeable array locations for plotting but the program here is not Private Sub DrawData Click ByVal sender As System Object ByVal e As System EventArgs Handles DrawData Click Dim dx As Double i stepmove right count i stepmove right count 1 For t 1 To 1000 m DataPlot t 500 Math Sin Math PI t 1000 i stepmove right count Next t dx 2 Math PI 10 2 i stepmove right count m MinXValue dx 1 stepmove left count 0 ShowTime Text m MinXValue show the maxmum time or min time PicDataView Refresh using refresh to advoid the value of time overlapping when the time is changeable DrawData call the subroutine of drawdata End Sub Private Sub Button4 Click ByVal sender As System Object ByVal e As System EventArgs Handles Button4 Click Dim dxl As Double i stepmove left count i stepmove left count I If i stepmove left count gt 8 Then control the minimum waveform plotted in the screen to make it look clearly i stepmove left count 8 End If For t 1 To 1000 m DataPlot t 500 Math Sin Math PI t i stepmove left count 125 Next t dxl 2 Math PI 10 i ste
41. ay be beyond the reference table therefore if statement should be used to test the conditions about the value of y1 and y2 If both of them are in the region of reference table the statement of drawing line will be executed directly On the contrary they should be forced to the maximum value of y1 and y2 and then the next statement will be performed as well He Miao PC Oscilloscope USB based 24 Universityof Hertfordshire School of Electronic Communication and Electrical Engineering BEng Final Year Project Report gt Using gr drawline x1 y1 x2 y2 hundreds or thousands of related coordinates points or data come into being a track like sine wave And in order to plot data by using sine function the points in the coordinates system have to be moved forward through some track Accordingly the x1 should be forced to x2 and then the loop will be back to the start that drives the loop continues to cycle until all the data hold in the m_DataPlot array is drawn out 2 4B Plot data draw data using sine function Start Define t as counter i gt Add usercontrol1 to form of plotting Usercontrol11 data 500 Math Sin Math PI t 500 data The programming language of this part should be developed in the Code Editor for the required interface to the user Figure 10 the counter t cannot be less than the locations or the amount of data stored in the m DataPlot a
42. cLineColor Value End Set End Property Private Sub SerialPortl DataReceived ByVal sender As System Object ByVal e As System IO Ports SerialDataReceivedEventArgs Handles SerialPortl DataReceived End Sub End Class Part 2 Serial Port setting Public Class usbdriver Public Shared ReadSize 4096 Public Shared WriteSize As Integer 4096 Dim SPPause As Boolean False Dim SPClose As Boolean False Dim Datareceived 4096 As Integer 4096 As Integer Dim USBarray 4096 As Byte the buffer in pc Private Event DataUpdatel Private Sub usbdriver Load ByVal sender As System Object ByVal e As System EventArgs Handles MyBase Load Alart Init Q System Init Q Gets or sets the size of the SerialPort input buffer adjust the comport buffer and process the buffer when receiving data With SerialPortl ReadBufferSize ReadSize WriteBufferSize WriteSize End With He Miao PC Oscilloscope USB based 62 University of Hertfordshire School of Electronic Communication and Electrical Engineering BEng Final Year Project Report Me SerialPortl SerialPort setting SerialPortl use to realize the serial port shared between the user controls and the forms End Sub Sub System Init Q the initialization of the comport CombSerPort Items Add COMI CombSerPort Items Add COM2 CombSerPort Items Add COM3 CombSerPort Text COMI the initialization of the baudrate bit per second CombBaudRat
43. cation channel with the USB module as step 4 shown in Figure 7 and the other control called OpenFileDialog in case of the windows applications process data from file therefore an interface is needed to select files to open and save The NET Framework provides the OpenFileDialog amp SaveFileDialog classes to do just that Furthermore the USB button on the bottom of right side consists of the serial port settings and the programming for communication so that another interface was designed COMFORT Configuration l I l l I I tertie E l p l I i oe gem it l I EH E l I i p I I i l I Figure 9 Serial Port setting The configuration of serial port such as BaudRate Parity DataBits and StopBits was implemented in this interface and on the right the buttons named open port amp close port were chosen for controlling the COM port in PCs which was an essential tool for testing serial port due to different computers often have different COM ports With this part should make the system work more conveniently and perfect The black colour component is regarded as a sign to indicate the status of the serial port When the light becomes to red means the port is close and the green shown the port is open Alternatively from windows 95 it allow the serial port setting to be set by selecting my computer properties Device Manger Ports COM and LPT Port Settings After developing the ActiveX control component for plotting
44. chart of step 2 4 B plot data rrrrrrrnnnrrrrnrrnnnnnrrrrrnnnnnrrnrnnnnnnrnnnnnnnnnennnnnnsnne 23 Figure 19 Sub flowchart of step 2 4 B Plot data draw data using sine function 25 Figure 20 Integration of each part for step 2 26 Figure 21Test serial port ERR TEE 27 Figure 22 Oscilloscope simulation structure cccccccceseeeeeeeceeeeeceeeceeeseceeesaaeeeeeeesaaaeeeeeessaaeeeees 27 Figure 23 Sub flowcharts for adjusting amplitude and rescaling size 28 Figure 24 Sub flowcharts for position control down middle S up right 30 Figure 25 Sub flowcharts for time div Control 31 Figure 26 USB communicalor WIN RE 32 PIOUS 27 SIN denne 33 FOUG SPUNNET 34 Figure 29 Position changes simulation rrrrnnnnrrnrnnnnvnvnnnnrnnnnnnrvnvnnnnrnvnnnnrnnnnnnsnnnnnnsnnnnnnennnnnnsnee 34 Figure 30 9 pin D type connector oopback 35 Figure 31 USB Bus Powered configuration DO 36 Figure 32 Representation of data graphically cccccccccccsseeeeeeeeeeceeseeeeseeeesseeeeeseeeeeesseeeeeens 38 Figure 33 Oscilloscope simulation amplitude changdes 39 Figure 34 Special situation of amplitude changes rrrnrrnnnrnrrnnnnnnnnrnnnrnnnnnrrnnnnnnnnrnnnnnnnnnrnnnnnnenee 39 Figure 35 Oscilloscope simulation time div sssseseeessssseseeeeeeeennn nennen 40 Figure 36 Oscilloscope simulation position Control 41
45. chool of Electronic Communication and Electrical Engineering BEng Final Year Project Report Chapter 2 Project development and implementation Chapter overview The coordinate system the method of draw line and draw text and the features of the RS 232 cable and USB port have discussed above In this chapter the project design the flowchart instead of source code for describing the implementation of this subject together with some explanations the serial port test by using RS 232 cable and the installation of USB module will discuss in detail 2 1 Project overview and design 2 1 1 Project overview 1 Visual Basic Programming Figure 7 Project overview In the communication world there is always a need to evaluate data it is preferable for them to be presented in a graphical format In order to carry out this aim the subject can be splitted into five steps as shown as Figure 7 This project should focus on developing software At the beginning a user interface to plot data graphically and adjust the trace presented data in some ways was built using Windows Forms in the Windows applications and then changed to create the custom controls known as ActiveX control which is so useful is that they are reusable It was Visual Basic programming language that supported main work When it comes to step5 USB installation would be done after the communication programme was ready for receiving data In the following section
46. cost Remarks Visual Studio 2005 Software Download from website Software needed for system Package http fsc feis herts ac uk implementation and testing USB cable Type A amp B Around 3 also available Hardware accessories in Final year project lab needed for connecting USB Bread board Resource available in lab adapter RS 232 Cable Resource provided by Mr Used for testing VCP NN DLP USB 245 User manual Resource provided by evans USB drivers Download from website TT rane Table 1 Cost analysis 1 6 Report outline gt Chapter 1 according to literature research this chapter concentrates on the related basic theory including the graphics operation and fundamentals and performance of USB module and RS 232 cable gt Chapter 2 Based on the discussion of chapter 1 it emphasis on the development of software design for instance how to plot data and how to simulate oscilloscope s functions which are primary work in this project The hardware actualization like testing serial port and USB port installation is involved as well gt Chapter 3 The testing and simulation results associated with error analysis are presented in this chapter Chapter 4 The problem and shortcomings have not resolved the improvements of the project and the difficulties in the procedure are stated Also main progresses are mentioned Finally the previous work is concluded briefly as well Summary For what has been discussed above
47. data it still needs an interface as a platform using the form to execute the function of the existent control called UserControl1 by default He Miao PC Oscilloscope USB based O University of Hertfordshire School of Electronic Communication and Electrical Engineering BEng Final Year Project Report Amplitude p Time LI Position I mmer Ma Last value Transmit String Receive String Figure 10 Run interface Sometimes more than one user control is added into this interface called usercontrolt1 and usercontrol12 by default to carry out specific task that provides a simple way to contrast and analyze among different curves Similarly the Dual trace oscilloscopes display two V t graphs at the same time so that simultaneous signals from different parts of an electronic system can be compared In addition this interface can be shown to the user in practical work unlike the ActiveX control before that is just for the designer When it comes to the USB port installation the USB adapter should be inserted into the bread board ready for the pin connections Then USB port is connected to the PC via a standard 6 foot USB cable 2 2 Project implementation USB data to PC transmit Time div Amplitude Figure 11 Program structure diagram He Miao PC Oscilloscope USB based 17 University of Hertfordshire School of Electronic Communic
48. devices with RS 232 interfaces include printers data acquisition modules test instruments and control circuits Sometimes a simple link between computers of any type by using RS 232 can be achieved Furthermore the hardware and programming requirements for RS 232 are simple and inexpensive and because so many existing devices already have the interface built in An RS 232 link may use any of a number of connector type pin configurations and combinations of signals These days most PCs use a 9 pin male D sub connector for serial ports These include only the nine signals Used for connections between DTEs and voice grade modems and many other applications The Figure 5 shows popular connectors used in RS 232 interfaces and the pinouts of the connectors 7 He Miao PC Oscilloscope USB based University of Hertfordshire BEng Final Year Project Report DB 9 Female DCE DB 9 Male DTE RS 232 Pinout R5 232 EIA 232 A Function DB 25 pin DB 9 pin Shield 1 Transmit Data TD from DTE to DCE 2 Receive Data RD from DCE to DTE j Request to Send RTS 4 Clear to Send CTS 3 DCE Ready DSR 6 Signal Ground SG ri Received Line Signal Detector DCD 8 DTE Ready DTR 20 Hing Indicator 22 Figure 5 RS 232 D sub connectors and pin locations for RS 232 connectors 9 The device that connects to the interface is called a Data Communications Equipment DCE and the device to which it connects e g the computer is call
49. e desired system in order to choose the right components in a discerning way It is commonly accepted that essential apparatus include analogue measurement acquisition tool amplifier filter ADC and DAC and some transmitting and receiving equipments 1 2 Motivation and challenges The communication via USB based without the need for an external power supply and allowing some devices to be used without requiring individual device drivers to be installed Also it allows devices to be connected and disconnected without restarting the computer Therefore as the improvement of USB the communication becomes more and more conveniently and efficiently Human prefers to read or analyze the data information in an easier way like present the desired data graphically And then the trace presented data may need to amplify de amplify or shift in order to obtain the expected effect Although the software development tool Visual Basic 2005 easily designs great looking and easy to use applications using an intuitive drag and drop interface designer it is still a new programming language hence VB for programming on PC should be a hard and challengeable work The communication program between the PC based on virtual serial port and USB module is still a key issue He Miao PC Oscilloscope USB based Universityof Hertfordshire School of Electronic Communication and Electrical Engineering BEng Final Year Project Report 1 3 Aim and
50. eal world to generate data It may take a variety of forms At the simplest level data acquisition can be accomplished by a person using paper and pencil recording readings from a volt meter ohmmeter or other instrument Personal computers are being used in data acquisition with special data acquisition boards installed in the computer These boards are inserted into the He Miao PC Oscilloscope USB based Universityof Hertfordshire i EI School of Electronic Communication and Electrical Engineering BEng Final Year Project Report chassis of the computer and allow it to be connected to external devices such as sensors probes and other monitoring devices The computer provides many attractive features to the data acquisition like high clock speed programming flexibility mass data storage and etc 1 So Acquired data always can be displayed analyzed and stored on a computer and using various general purpose programming languages such as BASIC C Java can be developed for custom displays and control A specialized programming language used for data acquisition like the series of Visual Basic which offers a graphical programming environment optimized and built in graphical tools and libraries for data acquisition representation and analysis A data acquisition system is a device designed to measure and logs some required parameters To set up a data acquisition system the user should know exactly the characteristics of th
51. eath 1 The long top and bottom row of holes are usually used for power supply connections The row with the blue strip beside it is used for the negative voltage usually ground and the row with the red strip beside it is used for the positive voltage The circuit is built by placing components and connecting them together with jumper wires Then when a path is formed from the positive supply node to the negative supply node through wires and components we can turn on the power and current flows through the path and the circuit comes alive 1 1 Title using the bread board available at http www iquanalabs com breadboard htm He Miao PC Oscilloscope USB based Tice 5 n Hertfordshire School of Electronic Communication and Electrical Engineering BEng Final Year Project Report APPENDICE D Revised Gantt chart He i H in TASK NAME sp ED Duration A E 1 stud Literature research Understand Background infermation 10 10 07 Write feasibility report Read past report Desisn Block diagram of system 03 11 O7 14 11 07 ca ja z el m wl m i T uL m tm u mo i kr Leck ui T Eh IL e et el m EL e E ih i EL e m D H vi m S e H EL Ei D 3 ul m fa KL bh and Revier DEM Visual basic 2005 operation and architecture of USE F 151 external examiners E lg Hlementation rs a Design interfaces using controls Activex control for plotting data graphica
52. ed a Data Terminal Equipment DTE which is a device that controls data flowing to or from a computer In practical terms the DCE is usually a modem or other RS 232 device being controlled by a computer and the DTE is the computer itself or more precisely the computer s UART chip 9 1 3 2 DLP USB 245M User Manual Figure 6 DLP USB 245M User Manual 10 The DLP USB245M is the 2 generation of DLP Design s USB adapter This device adds extra functionality to its DLP USB1 predecessor with a reduced component count and a new low price It has several main features shown below 10 He Miao PC Oscilloscope USB based 12 Universityof Hertfordshire School of Electronic Communication and Electrical Engineering BEng Final Year Project Report Send Receive Data over USB at up to 1M Bytes sec 384 byte FIFO Transmit buffer 128 byte FIFO receive buffer for high data throughput Simple interface to CPU or MCU bus Protocol is handled automatically within module A FTDI s Virtual COM port drivers eliminate the need for USB driver development in most cases Integrated Power on Reset Circuit USB VID PID serial number and product description Strings stored in on board EEPROM s EEPROM programming on board via USB Virtual COM port VCP Drivers for windows 98 2000 and etc 10 The DLP USB245M provides an easy cost effective method of transferring data to from a peripheral and a host at up to 8 mil
53. em Drawing Pen Determines the color width and style of the line System Drawing Point Point structure that represents the first point to connect System Drawing Point Point structure that represents the second point to connect Table 2 DrawLine Method 5 Upon the description above how to draw line can be summed as Creates a pen Creates points for the endpoints of the line Draws the line to the screen 5 Draw text the common method is like Graphics DrawString Method String Font Brush PointF draws the specified text string at the specified He Miao PC Oscilloscope USB based University of Hertfordshire School of Electronic Communication and Electrical Engineering BEng Final Year Project Report location with the specified Brush and Font objects The parameters description in the following table Parameter name Function System string that String to draw Represents text as a series of Unicode characters System drawing font this Defines a particular format class cannot be inherited for text including font face size and style attributes PointF structure that specifies the upper left corner of the drawn text Table 3 DrawString method 6 Creates a text string to draw m Defines the font as Arial 16pt Creates a brush to draw with Creates a point for the upper left corner at which to draw the text Draws the string to the screen using the font brush and
54. ep 2 4 Plot data He Miao PC Oscilloscope USB based University of Hertfordshire School of Electronic Communication and Electrical Engineering BEng Final Year Project Report The description on Figure 15 a The function of a real oscilloscope is extremely simple it draws a V t graph a graph of voltage against time voltage on the vertical or Y axis and time on the horizontal or X axis As shown as Figure 16 left the screen of this oscilloscope has 8 squares or divisions on the vertical axis and 10 squares or divisions on the horizontal axis Usually these squares are 1 cm in each direction 11 lt gt Create graphics object gr when to draw line text or shape a graphics object named gr represents a GDI drawing surface should be created first by using to call the CreateGraphics method of a control or form to obtain a reference to a Graphics object lt Define four points the border of region was designed as a rectangle that was composed of two pairs of height and width consequently the four coordinates points need to be defined at the proper position according to the screen PicDataView shown as below VOLTS vertical axe T TIME Wgd ade hag FN P nd PicDataView same as Figure 8 E Md Figure 16 Real oscilloscope screen left vs stimulant oscilloscope screen right For example the width and height of PicDataView can be found like m endY PicDataView height a
55. est way On this condition the key is about using a variable along with the m Vnum or m Hum to draw lines at different positions When the lines are drawn from left to right the variable multiplies the m Vnum that means adding a distance of square towards y axis every time the pen will draw a line As time goes by when the 9 cycles of loop complete nine lines will appear in the horizontal direction of region A Then the same way to draw lines from top to bottom but the variable should multiply the m Hnum that describes the pen will draw a line as adding a distance of square towards x axis shown as Figure 16 right The further description on Figure 15 c lt gt Define offset the globe variable offset is defined to use for vertical midpoint that ensure the track representation of data is drawn from the middle of the reference table Ideally it should be calculated as the height of PicDataView minus the half of height of reference table This variable is so useful that will discuss in detail in the following section lt gt Calculate every step of x axis dx the resolution of x axis or the step of x will be used in the plot data part It depends on the width of reference table and the length of array hold the data Therefore it is defined as dx width m DataPlot lenght 1 sometimes it is called scaling Where width 2 m endX m startX 80 and m DataPlot is the array ready for plotting both of them have been alread
56. ffset if offset changes initially it is in the middle of the reference table all of the related points will remove together that result in the track will move as well Additionally the offset must be determined by both of up and down position changes to avoid jumping steps that means when the curve needs to go up or go down from the current position gt Setthe counter i stepup count 0 after adjusting the curve to go down the other counter i stepup count must be set to zero that is because this statement is used to avoid jumping steps due to whenever finishing the up function and converting to the down button the other counter should be added from start Simply speaking the two counters for controlling the curve to go up and go down must be independent from each other in the following section of function judgment will discuss this point graphically Start Define a counter 1 i207 ves Update dx amp Ke The control named time div next point x2 D predicates the distributive locations for plotting increases or decreases as No Update Tor loop of table shown above Backto the flow plotting data part chart on the left since the length of l array m DataPlot is altered the corresponding parameters like the t eS Za resolution or step of x axis dx and ictor pad next point x2 of x axis In a word it influences the whole programme for plotting data End Figure 25 Sub flowcharts for
57. for adjusting amplitude and rescaling size The explanation on amplitude control gt Process the m_MaxValue amp m_MinValue As mentioned in plotting data part the m_MaxValue amp m MinValue can be defined to describe the amount of data intended to show which determine the scaling of y axis dy Furthermore the dy is used to define the y axis of current point y1 amp the next point y2 in the sine wave On account of this if the amplitude of the curve intends to be altered the corresponding parameter m MaxValue amp m MinValue should be updated as well For instance assuming multiply them by 1 as a reference level thus the sine wave should be multiplied by 1 1 to zoom in and multiplied by 0 9 to zoom out However when it is zoomed in after several times it will be drawn outside the reference table so that the source code should be developed to restrict the trace as Figure 18 shown above He Miao PC Oscilloscope USB based 28 Universityof Hertfordshire i EI School of Electronic Communication and Electrical Engineering BEng Final Year Project Report Refresh method the refresh is utilized to avoid the variable overlapping of the amplitude Call plotting data subroutine this subroutine points to the DrawData mentioned above that includes about drawing reference table and plotting data When click the zoom in or zoom out control the track will disappear if the DrawData
58. form the serial communication It is also can be said it becomes a link between the programming language and the external device USB module So the testing is a necessary procedure during the project implementation The flow chart on testing serial port is shown below Double click the send button in the design interface of Usercontrol1 which converts to Code Editor Mode and call SPDataSend subroutine that is edited to execute the function of serial port The key component is j when to tell the serial port to send Call M Subroutine data or receive data therefore the if statement is called to tell conditions for serial port open or close When SEH geet j the serial port is open the program open A writes the data to the buffer of serial port using SerialPort1 Write method In other words the serial port sends the data to the buffer The received WII data can then be retrieved from the buffer by a function called Serial Port Y SerialPort1 Read This step should E work together with the RS 232 cable that will discuss in the following section Eventually if the transmitted data can be received over the serial port that proves the serial port is Working and vice versa Figure 21Test serial port Until now the first objective on the graphical representation of data specific on plotting data using Act
59. gn DLP USB245M G USB to FIFO Parallel Interface Module internet Available at URL http www dlpdesign com usb dlp usb245mv15 pdf Accessed February 2008 Data sheet provided by Georgios Pissanidis He Miao PC Oscilloscope USB based 51 Hertfordshire School of Electronic Communication and Electrical Engineering BEng Final Year Project Report 11 Title using an oscilloscope internet Available at URL http www doctronics co uk scope htm scope pic Accessed 23 March 2008 12 Title Pico Technology 10 reasons why you need a PC oscilloscope internet Available at URL http www picotech com 10reasonswhyyouneedapcoscilloscope html Accessed 30 March 2008 13 Proakis John G Digital signal processing principles algorithms and applications 1996 Prentice Hall ISBN 0 13 394289 9 Chapter 1 pp4 5 14 Title Pico Oscilloscope Range internet Available at URL http www picotech com oscilloscope specifications html Accessed 2 April 2008 He Miao PC Oscilloscope USB based 52 Universityof Hertfordshire School of Electronic Communication and Electrical Engineering BEng Final Year Project Report BIBLIOGRAPHY 1 Title MSDN Home page MSDN Library URL http msdn2 microsoft com en ab default aspx 2 Willis Thearon Beginning Visual Basic 2005 Thearon Willis and Bryan Newsome 2005 Wiley Pub IBSN 0764574019 He Miao PC Oscilloscope USB based 53 Univer
60. ick SPDataSend End Sub Sub SPDataSend send data button If SerialPortl IsOpen False Then test the serialport open or not MessageBox Show The COM is not existing or occupying error MessageBoxButtons OK MessageBoxIcon Error MessageBoxDefaultButton Buttonl Exit sub Else SerialPortl Write SData Text write data into the buffer SData Text show the written text RData Text SerialPortl ReadExisting read data from the buffer but there will be a limitation for receving End If End Sub Private Sub RData TextChanged ByVal sender As System Object ByVal e As System EventArgs Handles RData TextChanged End Sub Alternatively use OpenFileDialog to acess data Private Sub DataRead Click ByVal sender As System Object ByVal e As System EventArgs Handles DataRead Click Dim m DataFile As String OpenFileDialogl ShowDialog m DataFile OpenFileDialogl FileName End Sub Zoom out trace Private Sub ShowMax Click ByVal sender As System Object ByVal e As System EventArgs Handles ShowMax Click here for zoomming out m MaxValue m MaxValue 0 9 m MinValue m MinValue 0 9 MaxValue Text m MaxValue PicDataView Refresh DrawData End Sub Zoom in trace Private Sub ShowMin Click ByVal sender As System Object ByVal e As System EventArgs Handles ShowMin Click here for zoomming in m MaxValue m MaxValue 1 I m MinValue m MinValue 1 I MaxValue Text m M
61. ifferentiate waveforms And USB 2 0 can transfer data at speeds of up to 480 Mbit s Using USB 2 0 PC Oscilloscopes give user incredible performance with fast screen updates and the ability to stream data Furthermore it can be used for data acquisition 12 Depending on PCOs capabilities the prices range from as little as 100 to 2000 therefore it suits for different customs incomes and needs Nowadays that Pico is the market leader in PC the modern alternative to traditional bench top oscilloscopes Such as PicoScope 2200 Ultra Compact USB Oscilloscopes is powerful yet easy to operate Users benefit from the power of the PC and the familiar Windows interface and controls making the software easy to learn and easy to use on a daily basis Drivers and examples are included for LabVIEW C C Delphi and Visual Basic for integration into custom applications 14 He Miao PC Oscilloscope USB based Universityof Hertfordshire School of Electronic Communication and Electrical Engineering BEng Final Year Project Report 3 Description of project work Chapter 1 Technical theory Chapter overview The background information the aim and objectives and the structure of the report were already indicated In this chapter the essential information and theory for carrying out the project is composed of the methods of plotting using Visual Basic language and the general description of USB port specifics on DLP USB245M User
62. igh 10 divide the PicDataView by 10 and each part is equal m Hnum widthl 10 Dim i As Integer draw the lines from top to bottom amp from left to right For i 1 To 9 gr DrawLine Pens White m startX 70 m startY 5 i m Vnum m endX 10 m startY 5 i m Vnum Next For i I To 9 gr DrawLine Pens White m startX 70 i m Hnum m startY 5 m startX 70 i m Hnum m endY 20 Next range change the scaling of y axis Dim m xMiV m xMxV m yMxV m yMiV m uMxV As String draw the text for diaplaying the amplitude time and position Dim dx As Double m yMxV CStr m MaxValue due to some of them are globe variables do not want to be confused and then change to another name m yMiV CStr m MinValue m xMiV CStr m MinXValue m xMxV CStr m MaxXValue m uMxV CStr m upValue m dMiV CStr m downValue Draws the specified text string at the specified location with the specified Brush and Font objects gr DrawString m yMxV Me Font Brushes Yellow 30 5 write the value at the front and end of the table use to present the amplitude and time of the waveform also alter as the waveform change gr DrawString m yMiV Me Font Brushes Yellow 30 390 gr DrawString m xMiV Me Font Brushes Yellow 68 405 gr DrawString m xMxV Me Font Brushes Yellow 458 405 gr DrawString m uMxV Me Font Brushes Yellow 30 197 5 gr DrawString m dMiV Me Font Brushes Yellow 30 197 5
63. in communication must understand a common language that is transferred with each other With the development of science and technology the ways are used to communicate have also improved Modern communication and measurement system designs are increasing in complexity and functionality as the latest high performance processors and DSP enable new signal processing techniques What is more the data transfer becomes much easier than before The USB Universal Serial Bus is a serial bus standard as interface or peripheral equipment to plug in PC has got highest data transfer rate up to 8 Mbits second Nowadays the USB specification is at version 2 0 Up to 480 Mbit s USB 2 0 applications commonly No matter what how much data is transferred only with the aid of one cable In that case it will save much space cost Communication as defined in the RS232 standard is an asynchronous serial communication method RS 232 is one of the most widely used techniques used to interface equipment to computers It uses serial communications where one bit is sent along a line at a time This differs from parallel communications which send one or more bytes at a time The main advantage of serial communications over parallel communications is that a single wire is needed to transmit and another to receive RS 232 is a standard that most computer and instrumentation companies comply with 2 Data acquisition sometimes called DAQ that is the sampling of the r
64. iscussed 4 2 Processes lay out ra g jen L ta wo m Ek CH Revised Gantt chart within Appendix D will show time organization of this project Figure A 3 rj Pp TASK NAE sp ED Duration Project Specification Feasibility study pp 10 10 07 Understand Background information sft tr s110 07 Ze Analysis and Understanding 1 1 y OT gt Study and Review pp Project seminars Design and Implementation 111 14 03 08 Test and Debugging pp Test project zt oz co fae osc Sw Write formal report lzozosloro o Ae Figure 43 Processes display kb 4 3 Difficulties in the procedure lt ndubitably the study and application of new language VB 2005 had to spend much time and energy together with lots of challenges must to be overcome So this procedure had gone on almost three months Additionally after studying the programming language the subjects were relative to the serial communication that had not been mentioned Hence how to compile the programming was still a new problem lt The confusions on the aim and objectives of project and the unfeasible actives that resulted in waste time He Miao PC Oscilloscope USB based Universityof Hertfordshire School of Electronic Communication and Electrical Engineering BEng Final Year Project Report lt As for developing program for plotting data at the beginning the choice of method did not support by VB 2005 but VB 6 0
65. ital Signal Processor RS 232 Recommend Standard 232 DAQ Data Acquisition VB Visual Basic COM Component Object Model UART Universal asynchronous receiver transmitter DTE Data Terminal Equipment DCE Data Communications Equipment FIFO First In First Out VCP Virtual COM port CPU Central Processing Unit MCU Micro programmed Control Unit VID Vendor ID PID Product ID DAC Digital to Analogue Converter GDI Graphics Device Interface IDE Integrated Development Environment He Miao PC oscilloscope USB based viii Universityof Hertfordshire School of Electronic Communication and Electrical Engineering BEng Final Year Project Report 1 Introduction This section based on feasibility report before contains a brief statement of background information and system description of the subject the reasons for undertaking the work the aims and objectives and the methods employed to achieve these objectives 1 1 Background In modern times desired data information is frequently analyzed and utilized by people to develop business industry and applications in various fields As time goes on the communication and data acquisition system have become core and popular techniques Generally speaking communication is a process that allows human and animals and other living beings to exchange information by several methods in the world It exists everywhere by means of many kinds of forms Everything takes part
66. ith canvas that can be used to group collections of controls If the Panel control s Enabled property is set to false the controls contained within the Panel will also be disabled On the top of the right side several controls were designed to undertake the oscilloscope simulation including labels provides run time information or descriptive text for a control Buttons Raises an event when the user click it and texts enable the user to enter text and provides multiline editing and password character masking 3 For example the amplitude of the track shown on the left will be zoomed in or zoomed out when the user click the corresponding buttons Hence the three text controls are for showing value of changeable He Miao PC Oscilloscope USB based 15 Universityof Hertfordshire School of Electronic Communication and Electrical Engineering BEng Final Year Project Report amplitude time and position and the six buttons are used to control or adjust these events occurred The rest part in this figure is for carrying out testing The two text boxes are for display the transmission data and receiving data with the button named send data to control the event happened Adding another two labels is to describe the controls On the middle of the right side the text box is designed to display the value of last received data On the bottom of the user interface the serial port control selected which is utilized to undertake the communi
67. ity of Hertfordshire BEng Final Year Project Report Up Down cl AHL EOTORE Read Data Mis Sh POE TT TETT Lo Im j GAGE HH FILT AMT HV TT Kabes Figure 38 Different wave Cos function By changing the math function the different trace can be achieved In the same way the amplitude or position of cos wave also can be changed shown as Figure 38 above Actually from the last value shown that records the first point in the track therefore according to the math function the sine wave should be zero while the cos wave should be 500 But when adding the timer control in the user interface with the help of programming language the last value is mutative and durative number which also can be used to simulate the received data from external devices such as USB module Other waves also can be achieved by using different math function for instance Truncate Sart Tan or Round and etc see Appendix A He Miao PC Oscilloscope USB based 43 University of Hertfordshire School of Electronic Communication and Electrical Engineering BEng Final Year Project Report osition 3 BERGE j ea See e a ja Figure 39 ActiveX control reusable Adjusting the size of each control to ensure all controls could be visible and usable in the run interface Also these two traces could be altered the amplitude or position within Appendix A 3 2 Error analy
68. ive X control have completed Many controls of the oscilloscope allow user to change the vertical or horizontal scales of the V t graph so that it can display a clear picture of the signal user want to investigate The following procedure is the oscilloscope simulation The general components can be designed as following illumined Figure 22 Oscilloscope simulation structure He Miao PC Oscilloscope USB based 27 University of Hertfordshire School of Electronic Communication and Electrical Engineering BEng Final Year Project Report According to Figure 22 actually rescaling the control size in the run interface does not belong to the oscilloscope simulation and it is used when the user wants to observe and analyze more than one control in the interface as Figure 10 shown Hence designer should guarantee all the functions of the controls still working as expected As for the amplitude position and time in the practical operation they are common controls of an oscilloscope therefore the aim of this part is to simulate their function The flow chart listed below for every part will go into particulars DasignM oder Yes m MakValuc amp m_MinValue restrict the minimum define the position No of plotting L area PicDataWMiew Refresh Cal Nim subroutine Depend on the positon of plotting area to define other controls positon Figure 23 Sub flowcharts
69. lion bits 1 Megabyte per second Its simple FIFO like design makes it easy to interface to any microcontroller or microprocessor via IO ports To send data from the peripheral to the host computer simply write the byte wide data into the module when TXE is low If the 884 byte transmit buffer fills up or is busy storing the previously written byte TXE is taken high by device in order to stop further data from being written until some of the FIFO data has been transferred over USB to the host 10 When the host sends data to the peripheral over USB the device will take RXF low to let the peripheral know that at least one byte of data is available The peripheral then reads the data until RXF goes high indicating no more data is available to read By using FTDI s virtual COM Port drivers peripheral looks like a standard COM Port to the application software 10 As for hardware accessories USB cable amp Bread Board which are used for installing USB adapter within Appendix C Summary This chapter introduced the concept and methods of relative theory ready for developing software design such as how to draw lines and draw text using VB2005 Also the fundamental information on hardware devices was presented After that the following chapter will introduce the practical work development for this project based on the theory mentioned above He Miao PC Oscilloscope USB based University of Hertfordshire S
70. ll l12 Develop communication program between USB and PC 7 08 Hardware installation Le T 1 OF 2 OF 1 OF Ce 1 Le 2 Test project 03 Evaluate test results and correct software developmen zs oz 08 14 03 08 2 il OT 04 08 14 O4 OG 14 04 OF AF r T j Lei rg e n IA m m M vm m ta T m Ip o mE z EE E mmm E etm H o E rn el nm rk e CH cr Lr a EL EB m M jH D Uu v Im IR EL m D le Ip m a fade fem od z E eO m Dag H or p E m D ml WO D Bie m A D e Lech kW m e EL Fh e m a m ul m D e E e m m R3 bw vil il je OCTOBER NOVEMBER DECEMBER JANUARY FEBRUARY MARCH April 104 1743 2404 31m4 Sed 16e zie 4206 100 16 tse Feb 1600 E ek 1409 2104 2804 Teh 140 Sted re eed soe Figure A 3 Gantt chart Miao PC Oscilloscope USB based 74 Universityof Hertfordshire School of Electronic Communication and Electrical Engineering BEng Final Year Project Report He Miao PC Oscilloscope USB based 75
71. mp m_endX PicDataView width Therefore the coordinate of P1 may be defined as 70 5 P2 70 m endY 20 P3 m endX 10 m endY 20 and P4 m endX 10 5 lt Draw the border of table four lines connecting every two points specified by the coordinates by using gr Drawline Pen Point1 Point2 format can be drawn where the pen is chosen to determine color or style of the line The explanation on Figure 15 b Define the range of reference table For what has been discussed above the reference table was designed as rectangular so that height and width can be utilized to determine the range of it On account of this the range of reference table He Miao PC Oscilloscope USB based 21 Universityof Hertfordshire School of Electronic Communication and Electrical Engineering BEng Final Year Project Report Height P2Y P1Y m endY m startY 25 Likewise width 2 m endX m startX 80 where the m startY and m startX are defined as 0 initially lt Divide the plotting region by 10 from Figure 16 the region A was framed to be separated into 10 squares or divisions on the vertical axis and 10 squares or divisions on the horizontal axis Such as m Vnum height 10 amp m Hnumzwidth 10 where the m Vnum and m Hnum figure every divisions of the screen which is prepared for next step lt Draw lines from left to right amp from top to bottom two for loops and the gr Drawline method to carry out this step is the b
72. ndles Buttond Click SerialPort setting Show display the another window for USB setting cosist of the COMPORT configuraion amp communication backchannel between USB amp PC CE o L Trace goes down this part for down position control similarly as up before Private Sub DownButton Click ByVal sender As System Object ByVal e As System EventArgs Handles DownButton Click downdata da m endY high 2 20 tmpPosDow tmpPosUp m upValue da TextBox3 Text m upValue PicDataView Refresh DrawData End Sub He Miao PC Oscilloscope USB based 61 Universityof Hertfordshire School of Electronic Communication and Electrical Engineering BEng Final Year Project Report Sub downdata If offset lt m endY 100 Then i stepdown count i stepdown count I tmpPosDow tmpPosDow i stepdown count 20 offset m endY high 2 20 tmpPosUp tmpPosDow End If i stepup count 0 End Sub Add new properties for user control add the property for background color for plotting region in case the user wants to change the color when using this system because customs can not see the design interface Public Property PicGraph color As Color Get Return cBackColor End Get Set ByVal Value As Color cBackColor Value PicDataView BackColor cBackColor End Set End Property Public Property PicGraph Line As Color Get Return cLineColor End Get Set ByVal Value As Color
73. ne its initial value so that the position control can work m startX 0 m startY 0 m endX PicDataView Width find the PicDataView screen region like canvas m endY PicDataView Height high m endY m start 25 the range of reference table screen the region for plotting widthl m endX m startX 80 offset m endY high 2 20 make sure at the beginning of plotting data at vertical middle point End Sub Add data property add the data as public property usd for plotting and tell the control when to receive data instead of variable due to sometimes it should be globe not local Public Property data As Integer Get Data values are write only no read End Get Set ByVal Value As Integer iData Value If Me DesignMode False Then to raise an event I need to specify the raiseevent statement passing it the event name as well as the parameters for the event being raised RaiseEvent DataUpdate if it is in the run mode call the dataupdate event to update incoming data put them in the array ready for plotting and then plot them End If End Set End Property Update array out the received data in the dataArray ready for plotting or data array update Private Sub MainWin DataUpdate Handles Me DataUpdate Dim iDataCounter As Integer For iDataCounter m DataPlot Length 1 To 1 Step 1 it can be changed to 1 to m DataPlot Length 1 step 1 if like this the sequence for plotting also should be al
74. nge m range dr CDbl high m range the resolution of between unit pixel in the region of window display or the scaling of y axis End Sub Lin t As Integer Trace goes up Private Sub upbutton Click ByVal sender As System Object ByVal e As System EventArgs Handles upbutton Click updata da m endY high 2 20 tmpPosUp tmpPosDow this is not exactly value now shoud check it m upValue da TextBox3 Text m upValue PicDataView Refresh DrawData End Sub Sub updata If offset gt 100 Then choose the offset value to control the sine curve can not disappear from the plotting region when using the up button i stepup count i stepup count 1 i stepup count as a counter amp every time add 1 to make the curve go up step by step tmpPosUp tmpPosUp i stepup count 20 the variable tmpPosUp stands for the changeable portion offset m endY high 2 20 tmpPosUp tmpPosDow due to all the data to plot using sine model based on the offset point the other points in the curve change as the offset changes tmpPosDow means from this position when the curve wants to go up in that case to avoid the step jump End If i stepdown count 0 in that case to avoid the step jump because every time finish the up function and convert to the down button should be from the start End Sub Private Sub Button5 Click ByVal sender As System Object ByVal e As System EventArgs Ha
75. nns 38 He Miao PC oscilloscope USB based iv Universityof Hertfordshire School of Electronic Communication and Electrical Engineering BEng Final Year Project Report e Kg A E E 38 Se ENO Tay SE 44 C bru Wei 0 he e ET 44 3 20 QSCIIOSCONE SIMULA UON e eaea ireas 45 323 Seral OM TES uienring aa um 45 Chapter 4 Conclusions and future development 46 4 1 Project work summary sssssssssssesseeeeee nennen nennen nenne nnns nhan nnns na nnns nnn nnns nan nnn 46 4 1 1 Practical outcomes nennen nennen nennen nnns nna nnns nnns nnns na nns 46 4 1 2 Cost and market needS eene enne nnne nsn nnn nnns 46 4 1 3 Report conclusion nennen nennen nennen nnn nnn nnn nnn nnns 47 4 2 Processes lay OU TT mms 47 4 3 Difficulties in the procedure esses nnne 47 4 4 Future development 48 4 4 1 Extended Advanced functions on oscilloscope simulation 48 4 4 2 USB connectivity between PC amp Dh 49 aimi Eee 51 se MOTEN cere eee crass eer ec ges NN R 53 luce M ee 54 APPENDICE A Software Source code amp Test results rrrrrrrrvvrrrnnnrrvvrrrnnrrrvrnrnnnrrrerrrnnnrrrernnnnnn 54 APPENDICE B Hardware DLP USB 245M Adapter 70 APPENDICE C Hardware Accessories USB cable amp Dread Board ssnsennnsnssnnnnnnnnnereesreenee 72 APPENDICE D Revised Gantt chat 74 He Miao
76. ntional RS 232 interface or the port may be dedicated for use by an internal modem or other device A PC may have other types of serial ports as well such as USB Firewire but these use different protocols and require different components Each serial port in a PC reserves a set of port addresses and most also have an assigned interrupt request IRQ line or level The ports are designated COM 1 COM2 and so on up together with some properties like BaudRate BitRate and etc 7 As for VB2005 it has a control SerialPort for serial Communication similarly the Mscomm control in VB6 0 Encapsulation some useful properties BaudRate DataBit Parity Encodings methods close read write open and events DataReceived ErrorReceived as SerialPort class and the programming application base on this virtual serial port Use this class to control a serial port file resource This class provides synchronous and event driven I O access to pin and break states and access to serial driver He Miao PC Oscilloscope USB based 10 Universityof Hertfordshire School of Electronic Communication and Electrical Engineering BEng Final Year Project Report properties 8 The SerialPort VB2005 supported is a communication link between software and external devices 1 2 2 Buffers Buffers are another way that receivers can ensure that they do not miss any data sent to them Buffers can also be useful on the transmit side where they
77. o perform the desired operations on the input signal In applications the required output signal is another analogue output signal which requires a digital to analogue converter 13 The architecture of a data acquisition system utilizing the processing capability of a DSP Chip is a common method The great interest is the ability for users to stream fast data rates to a host in an economical way The new standard of USB 2 0 allows high speed data transfer between such a DSP peripheral or standalone and a host PC For software design the communication program for sending data to the USB module and the drivers for setting up the DAC channels should be developed For hardware implementation the Figure 48 provides the basic connection to a DSP board DLP USB245M USB B Connector Figure 48 Basic connections to a DSP board 10 Summary This chapter provides concise conclusions on the project findings and major information of this report with further development He Miao PC Oscilloscope USB based 50 Universityof Hertfordshire School of Electronic Communication and Electrical Engineering BEng Final Year Project Report REFERENCES 1 Rigby William H Computer interfacing a practical approach to data acquisition and control c1995 Prentice Hall Career and Technology Prentice Hall International ISBN ISSN 0132883740 Chapter 1 pp1 2 2 Buchanan William 1961 PC interfacing Communications and
78. objectives Aim The aim of this project is to graphically present data acquired over the USB port Objectives 1 Develop the ActiveX control component for the graphical representation of data 2 Develop the required graphical interface to simulate oscilloscope for presenting the graphical data to the user 3 Develop the communication backchannel for acquiring data from the USB module 1 4 System description Figure 1 Project System Figure 1 simply indicates desired system that how to undertake the data exchange between the PC and USB In Part 1 the PC is used to install received data and then the GUI window will be designed to present data in an intuitionistic way by using VB In part 2 the drivers will be developed to convert data information from RS 232 to USB and then complete the communication between the two components In part 3 USB setting up and the pins connections for powered configuration will be fulfilled To sum up this expected system is composed of software development and hardware configuration to realize graphical representation desired data He Miao PC Oscilloscope USB based Universityof Hertfordshire School of Electronic Communication and Electrical Engineering BEng Final Year Project Report 1 5 Costing Anticipated project costs were generated to ensure that project objectives could be met within the budget The initial cost analysis is displayed in Table 1 below Equipments Estimated
79. of x axis determine the horizontal scale of the graph which appears on the oscilloscope screen For example With 10 squares across the screen and the spot moving at 0 628 s DIV that is 0 62831 10 6 2831 2m The period of the curve can be calculated At the same time the amplitude can be altered as well depend on users themselves In fact for this project the time control means the locations of array changes for plotting in that case the realization of function here is not exactly that will particularize in the error analysis part He Miao PC Oscilloscope USB based 40 Hertfordshire University of School of Electronic Communication and Electrical Engineering BEng Final Year Project Report The Y POS control allows user to move the spot up and down the screen For the present adjust the trace so that it runs horizontally across the centre of the screen 340 Zeen In Zeen out ee Il 1 2566370614 PE eS Read Data EZ i Send Data T l SS v Figure 36 Oscilloscope simulation position control The variable offset is the most important factor for controlling the position changes and it must be changed to define as the globe variable If offset is still the local variable when using another controls like amplitude with the position simultaneously the sine wave will go back to the original position not currently Also the offset here must be related to the offset of
80. on Left PicDataView Width 100 DownButton Width 75 DownButton Height 20 DataRead Top 199 DataRead Left PicDataView Width 20 DataRead Width 75 DataRead Height 20 Label4 Top 239 Label4 Left PicDataView Width 27 Label4 Width 65 Label4 Height 12 TextBoxl Top 254 TextBoxl Left PicDataView Width 20 TextBoxl Width 156 TextBoxl Height 21 Label5 Top 296 Label5 Left PicDataView Width 27 Labeld Width 95 Label5 Height 12 SData Top 311 SData Left PicDataView Width 20 SData Width 156 SData Height 21 sendData Top 338 SendData Left PicDataView Width 20 SendData Width 75 SendData Height 20 Label6 Top 359 Label6 Left PicDataView Width 27 Label6 Width 89 Label6 Height 12 RData Top 374 RData Left PicDataView Width 20 RData Width 156 RData Height 21 Buttond Top 413 Buttond Left PicDataView Width 20 Buttond Width 75 Buttond Height 20 End If End Sub Private Sub SData TextChanged ByVal sender As System Object ByVal e As He Miao PC Oscilloscope USB based 57 Universityof Hertfordshire School of Electronic Communication and Electrical Engineering BEng Final Year Project Report System EventArgs Handles SData TextChanged End Sub Send data to buffer and receive it from buffer Private Sub SendData Click ByVal sender As System Object ByVal e As System EventArgs Handles SendData Cl
81. ork as expected Initial position Initial position Figure 29 Position changes simulation He Miao PC Oscilloscope USB based 34 Universityof Hertfordshire School of Electronic Communication and Electrical Engineering BEng Final Year Project Report As figure above shown when the curve goes up twice at point and then goes down must be from this current position not the initial position to avoid jumping steps Therefore in the programming design there was a parameter defined to record this position added to the calculation of offset If the curve goes down from point D to point and then need to go up again the other parameter also can be said the counter for controlling the trace to go up should be forced to zero because the counter always record the last position in that case when click the up button the curve will go up to the top of screen straight Following this point the system can execute as expected As for time div control the project does not work perfectly because the sine wave can be only adjusted the amount of periods has drawn in the window not the locations of array for plotting Maybe the reason is that the resolution of x axis has not been considered or some variables need to be declared as globe not local Another disadvantage on this system is that the communication backchannel between the USB and PC still exist some problem due to the serial port cannot read all of data from the
82. perty is a complex object such as a database or file connection or if it has parameter it should be carried out at run time 3 Obviously this property has a parameter and the DataUpdate event should be active at run mode hence at run time the property is manipulated and raise the event named DataUpdate lt RaiseEvent DataUpdate the user own events from the control named DataUpdate should be exposed that is allowed the custom who use this control to take action in their code when the event is raised Defining the DataUpdate event is as simple as adding an Event statement the event name the parameters that the event will return In this case the new event DataUpdate is performed to updating the array to store the idata To raise an event the RaiseEvent statement needs to be specified the event name DataUpdate as well as the parameters for the event being raised should be passed to it together The exposition on Figure 13 b lt Update idata to array The array ready for plotting called m DataPlot 1000 is defined as integer in the Public Class loop and 1000 means 1000 locations for holding data Therefore the received data need to be taken into this data array The m DataPlot array should allocate room to hold idata as the Figure 14 shown To realize this function the counter named iDataCounter was defined as a variable to alter and control the length of the m_DataPlot array After several
83. pmove left count 4 1 i stepmove count 125 m MinXValue dxl 1 stepmove right count 0 m MaxXValue dxl showTime Text m MinXValue ShowTime Text m MaxXValue PicDataView Refresh DrawData End Sub Key program for plotting data Sub DrawData m startX 0 m startY 0 m endX PicDataView Width find the region of PicDataView screen like canvas m endY PicDataView Height plot the border of reference table or the region for plotting Sets gr to a Graphics object representing the drawing surface of the control or form gr is a member of Call the CreateGraphics method of the form or control upon which want to render graphics Dim gr As Graphics PicDataView CreateGraphics Draw the border of screen gr DrawLine Pens White 70 5 70 m endY 20 gr DrawLine Pens White 70 m endY 20 m endX 10 m endY 20 gr DrawLine Pens White m endX 10 m endY 20 m endX 10 5 er DrawLine Pens White m endX 10 5 70 5 He Miao PC Oscilloscope USB based 59 Universityof Hertfordshire d EI School of Electronic Communication and Electrical Engineering BEng Final Year Project Report plot the every square divisions of the table used to measure the value of the curve like background of oscilloscope high m endY m startY 25 the range of reference table the region for plotting widthl m endX m startX 80 Dim m Vnum m Hnum As Integer m Vnum h
84. r Offset 100 Offset Updata subroutine m endY 100 Calculate the average step of Counter Counter position changes i stepdown count i i stepup count i ste stepdown_count 1 pup count 1 Show value Vary position according Vary position according nter to counter to counte Refresh h us Update Update offset offset Set counter Set counter i stepup count 0 i stepdown count 0 eu Figure 24 Sub flowcharts for position control down middle amp up right The discussion on the downdata subroutine in Figure 24 middle nearly the same as updata subroutine gt Offset lt m endY 100 m endY equals to the height of the PicDataView Using the if statement is to avoid the sine wave disappear from the region for plotting gt Counter i stepdown count zi stepdown count 1 i stepdown count is defined as a counter to adjust the position and it will be added by 1 as the down button is clicked every time automatically so that it is also a necessary variable for calculating the magnitude of position changes He Miao PC Oscilloscope USB based 30 Universityof Hertfordshire School of Electronic Communication and Electrical Engineering BEng Final Year Project Report gt Vary the position according to counter actually the value of position changes are ready for updating the offset that is based on the i stepdown count gt Update the o
85. r screen is set to 1 024 pixels across and 768 pixels down In Visual Basic 6 0 coordinates for forms and controls are expressed in twips while in Visual Basic 2005 coordinates are expressed in pixels so that the base currency of drawing is the pixel this means when the mouse is asked for its position a set of coordinates given in pixels should be got back In VB 2005 if the user clicks the mouse in the very top left pixel the coordinates of 0 0 will be shown and the user clicks in the very bottom right pixel the coordinates of 1024 768 will be got back However every window has a client area which is the area the programmer can use to report the program s output When the lines or shapes are drawn onto the control or form the user always dealing with this client area The coordinates used when drawing are adjusted so that the position of the window itself on the screen becomes irrelevant These coordinates are known as client coordinates 3 For example there are actually two different coordinates should be got for the top left corner of the Form1 paint area L Around 350 330 is the screen coordinates also known as the absolute position Around 0 0 irrespective of where the window is positioned on the screen and this is the adjusted client coordinates known as relative position 3 Figure 4 Coordinate System 1 1 3 Graphics operation The graphics class provides methods for drawing objects to the display
86. rray In that case it does not waste the room of the plotting region and vice versa And then the existent control called usercontrol1 as a common control will appear under the project toolbox that should be added to the plotting form After that the usercontrol1 becomes usercontrol11 in fact both of them are the same At the step 1 the public property called data has already added to the usercontrol1 that is used to tell the control when to plot the data instead of the variable In addition the sine function is defined as sin Byval a as double as double where a is an angle measured in radians so it must be multiplied by PI 180 to convert degrees to radians Therefore the statement for plotting can be written Usercontrol11 data 500 Math Sin Math PI t 500 where 500 is the amplitude and because the m DataPlot is designed to allocate 1000 locations at the beginning 500 is one period of the sine wave Figure 19 Sub flowchart of step 2 4 B Plot data draw data using sine function He Miao PC Oscilloscope USB based 25 Universityof Hertfordshire School of Electronic Communication and Electrical Engineering BEng Final Year Project Report Integration of each part for step 2 Start PicDataView like the canvas that is designed to Define panel display all the lines or text or shapes so that its height canvas region Iesse and width should be defined as a reference p
87. rties Private cBackColor As Color Color Blue Private cLineColor As Color Color White Private iData As Integer 0 add a user event for updating array Private Event DataUpdate Assign values to the globe variables Private Sub MainWin Load ByVal sender As System Object ByVal e As System EventArgs Handles MyBase Load Gets or sets the size of the SerialPort input buffer and adjust the comport buffer and process the buffer when receiving data With SerialPortl ReadBufferSize ReadSize WriteBufferSize WriteSize End With when in the designmode the border line of the PicDataView plotting region amp MainWin should be shown If Me DesignMode True Then Me BorderStyle Windows Forms BorderStyle Fixed3D PicDataView BorderStyle Windows Forms BorderStyle Fixed3D End If define the number amount of the data wanted to display currently at y axis m MaxValue 1000 He Miao PC Oscilloscope USB based 54 Universityof Hertfordshire School of Electronic Communication and Electrical Engineering BEng Final Year Project Report m MinValue 1000 just used for display the value of x axis dt 0 1 m MinXValue 0 m MaxXValue m DataPlot Length dt SerialPort setting SerialPortl Me SerialPortl to insure the virtual serial port can be shared between forms and user controls or this statement used to connect the serialport setting form and MainWin control make the offset as public variable and defi
88. s these five steps will be gone into particulars He Miao PC Oscilloscope USB based Universityof Hertfordshire School of Electronic Communication and Electrical Engineering BEng Final Year Project Report 2 1 2 Project design The programming language chosen for the development of software code was Visual Basic 2005 that was a part of Visual Studio 2005 The reason for this based around the advantages that VB changed the fact of Windows programming by removing the complex burden of writing code for the user interface UI By allowing programmers to draw their own UI it freed them to concentrate on the business problems they were trying to solve Once the UI is drawn the programmer can then add the code to react to events 3 2 Oscilloscope Simulation Amplitude NENNEN DranCurvet Den ms em en em EE EE EE EE EE EE EE Ss Receive String I I I l l I I d Virtual Serial Port 2 Plot data region 3 Test seri Figure 8 User interface for plotting data To build a form or a control the controls under the Tool Box are painted onto a blank window called Forms Designer using the mouse Each of these controls is able to tell the user when an event happens The window as shown above is called Usercontrol1 by default According to Figure 8 the blue colour area for plotting data using the panel control named PicDataView which is a control that contains other controls It is similar w
89. s more than 100mA cannot be plugged into a USB Bus Powered Hub e No device can draw more that 500mA from the USB Bus The power descriptor in the EEPROM should be programmed to a value of zero 10 Basic Bus Powered 9V System h Figure 31 USB Bus Powered configuration 10 Based on the DLP USB 245M pinout description see the Appendix B pin 3 should connect with pin 10 pin 11 and pin 12 respectively which supply 5V power to USB The pin 13 should connect with pin 14 that provides handshaking signal RXF and I XE to transmit and receive data He Miao PC Oscilloscope USB based 36 Universityof Hertfordshire School of Electronic Communication and Electrical Engineering BEng Final Year Project Report The USB driver is necessary component for DLP USB 245M working with PCs The following step on installing the USB driver 10 1 Download the DLL version of the device drivers from either dlpdesign com or ftdichip com Unzip the drivers onto a blank floppy disk or into a folder on the hard drive 2 Download the serializer program from either dlpdesign com or ftdichip com Unzip the package and place it in a folder on the hard drive 3 Connect the DLP USB245M board to the PC via a standard 6 foot USB cable This action initiates the loading of the USB drivers When prompted select the folder where the DLL version of the device drivers were stored in step one Windows will then complete the installation of
90. sable controls and components that can be added to the user s application These can range from buttons to data connectors to customized controls Design window the design window is where a lot of the actions take place This is where developer will draw user interface on the forms This window is sometimes referred to the designer Solution explorer this window contains a hierarchical view of developer s solution A solution can contain many projects whereas a project contains forms classes modules and components that solve a particular problem Properties the window shows what properties the selected object makes available 3 He Miao PC Oscilloscope USB based University of Hertfordshire School of Electronic Communication and Electrical Engineering BEng Final Year Project Report 1 1 2 The coordinate system of Visual Basic 2005 When Microsoft first released Visual Basic 1 0 it made building the user interface components of an application very simple Instead of having to write thousands of lines of code to display windows the very staple of a windows application known as a form that provides a platform for drawing line shape or text on the screen And the computer screen is made up of pixels They are very small but when working together they make a display on the screen Since pixels on any given display are always of a uniform size they are the common unit of measurement used in computer graphics Often the compute
91. scilloscope to measure the trace onto the canvas the blue colour part Figure 8 Next the flow charts will introduce how to realize to plot data graphically step by step based on Figure 12 Step1 Add new Property amp Update the array Start Defi i Add data Define coming data property Update data to array Text Box Show RaiseEvent DataUpdate Refresh Method a Adding Data Property Note DM DesignMode b Update array Figure 13 Step 1 Update array He Miao PC Oscilloscope USB based 18 Universityof Hertfordshire i EI School of Electronic Communication and Electrical Engineering BEng Final Year Project Report To add a new property called data a member variable idata should be declared in the public class loop as integer for storing a value When the value is changed it will call into the object and set the property When the property is set the text in the private member that was just defined needs to be set as well After that the new property will be exposed when the project is built The explanation on Figure 13 a lt Define coming data a variable idata working through the algorithm for the coming data is declared that can be passed to the default value of an empty integer for the data property lt DesignMode if the property is a fairly simple type such as String Integer or Boolean and does not have parameters it can be manipulated at design mode If the pro
92. serial Port Data send receive Yes Add property amp Update array Plot data Oscilloscope simulation Develop programme for communicating Install USB End He Miao PC Oscilloscope USB based BEng Final Year Project Report Figure 27 System flow chart Universityof Hertfordshire School of Electronic Communication and Electrical Engineering BEng Final Year Project Report 2 2 3 The function judgment 2 2 3 a plot data Generally speaking to plot data graphically should process the following procedures Storing data in the array Reading data from array Plotting data using math function Commonly using 2 dimension x y to express the pixel or coordinates point that make up of the track drawn in the screen Sine Y dimension stands for the data from array all of them should be drawn out one by one for plotting shown as table below It is the counter that defined to control reading data Also the plotting is a durative process and all points in the track can be only described as the current point and the following point Hence the points should go ahead that can be driven by x1equals to x2 Finally the math function is called to manage these relative points so that the plotting is working successfully Array for plotting Figure 28 Plot data 2 2 3 b oscilloscope simulation When it comes to the position control there are two important parameters to drive it to w
93. setting including the initialization and configuration of Ports name BaudRate Parity DataBits and StopBits by using an independent interface should be performed Then it connects with the main interface over USB button Figure 8 Q Add new property in the practical condition when the custom intend to change some property of user controls but considering that they are not allowed to control the design interface Figure 8 and only have access to the run interface Figure 10 adding new property to the control is a desired function And then in the Properties window it will appear under the existent control category In that case the custom can change some property optionally for instance the background of the screen or the line color of the sine wave depends on themselves Q Install USB as a matter of fact the installation of USB is about the hardware development including the powered configuration and USB driver installation LI Develop programme for communication when this step have been ready for communicating some corresponding parts will be updated together Q Offset as for transforming position time or amplitude this key variable have to be changed from local to globe type He Miao PC Oscilloscope USB based 32 University of Hertfordshire School of Electronic Communication and Electrical Engineering Design user interface COM Port Add new configuration Property Serial Port available Test
94. sis 3 2 1 Plot data Theoretically the offset should minus the data derived from the array when calculate the y dimension of the current and next point y offset m_DataPlot i dy However in that case the curve shifted abnormally as shown below PRECE CERTA PROPRECARRA EMP EN Leese j EXISTER ELE ESSA EE ERES A ILI 4 ese ees RRR Ko PER EET M i elle a eae ees RSR Figure 40 Turn analysis The reason of the curve on the left happened is that in the update array part the array is updated from the bottom of array m DataPlot Length 1 To 1 Step 1 not from the top results in the order of plotting data should be from maximum value to minimum t 1000 To 0 Step 1 when using the sine function and vice versa When both of them were provided with the correct corresponding relationship the expected result would lay out right Alternatively changing the equation y offset m DataPlot i dy to y offset m_DataPlot i dy is also a solution He Miao PC Oscilloscope USB based 44 University of Hertfordshire E School of Electronic Communication and Electrical Engineering BEng Final Year Project Report 3 2 2 Oscilloscope simulation were clicked continuously the value Neen ATT LETT for explaining the position changes was not correct any more 329 That is because the offset displacement does not respond to the show value GITTE SHIT HARARE ASEA JIA HBEZaSHuU
95. sityof Hertfordshire School of Electronic Communication and Electrical Engineering BEng Final Year Project Report APPENDICES APPENDICE A Software Source code amp Test results E Source code Part 1 On plotting data and oscilloscope simulation Globe variables definiation Public Class UserControll Public Shared ReadSize 4096 Public Shared WriteSize As Integer 4096 the counters statement for the realization of oscilloscope s functions Dim i stepup count As Integer as a counter used for adjusting the position of trace Dim i stepdown count As Integer Dim i stepmove right count As Integer as a counter used for adjusting the time div of trace Dim i stepmove left count As Integer Dim offset high widthl As Integer declare these three as globe public variables Dim m startX m startY m endX m endY As Integer the range of the data shown Dim m MaxValue m MinValue As Integer data range for display Dim m MaxXValue m MinXValue As Double text for showing the time div Dim m upValue m downValue As Double text for showing the value of position Dim m DataPlot 1000 As Integer the data array ready for plotting amp more data plotted and more smooth of the curve Dim m range m screen range As Integer the changeable portion for the controls like amplitude time and position Dim dy As Double Dim dt As Double Dim da As Double Dim tmpPosUp As Integer 0 Dim tmpPosDow As Integer 0 declare variables for adding new prope
96. tered such as For i m DataPlot Length 2 To 0 Step 1 m DataPlot iDataCounter m DataPlot iDataCounter 1 Next iDataCounter m DataPlot 0 iData put the incoming data in the zero position of the m dataplot TextBoxl Text iData to shown the last data Me Refresh End Sub He Miao PC Oscilloscope USB based 55 Universityof Hertfordshire School of Electronic Communication and Electrical Engineering BEng Final Year Project Report Use paint event to draw data Private Sub MainWin Paint ByVal sender As Object ByVal e As System Windows Forms PaintEventArgs Handles Me Paint insure only at the run mode the data can be plotted If Me DesignMode False Then DrawData End If End Sub Rescal the controls size Private Sub MainWin Resize ByVal sender As Object ByVal e As System EventArgs Handles Me Resize adjust it to work under activeX control or Windows Control component and put in here code to rescale all the controlls on your form when the activeX control is reuseable the size of it should be changed to make all of the ActiveX control can be shown clearly If Me DesignMode True Then restrict the minimum size of the usercontroll If Me Width lt 500 Then Me Width 500 End If If Me Height lt 450 Then Me Height 450 End If first define the position of the screen region plotting area and then use it as a reference to control the other controls size and position Pic
97. tfordshire School of Electronic Communication and Electrical Engineering BEng Final Year Project Report FIFO IO Pin Characteristics VCCIO 3 3v Parameter Description Min Typ Max Units Conditions Von Jouputvotage Hin 27 32 vo ises vor ouuvotageton 91 or v smed vin mout swima mesoa 10 14 18 V roet Vass _ InputSwichingrysiowss 200 RESET Pin Characteristics Parameter Description Max Units Conditions vn A NER RNC RERO UN NS RN Vays neu Switching Drees 200 m O RSTOUT Pin Characteristics Parameter Description Min Typ Max Units Conditions Voh Ouputvotage ih 30 35 V isouce 2m Ho Jteakagecunem mue 5 aa USB IO Pin Characteristics Parameter Description Min Max Units Conditions UVoh IO Pins Static Output High RI 1k5 to 3V3Out D RI 15k to GND D os 20 v_ es oitornieicommen Nose o8 2s vO avoir _ Ditferential nput Sensivaty 02 _ v S bz Driver Output mpedance 20 4 omm Nowa APPENDICE C Hardware Accessories USB cable amp Bread Board There are several types of USB connectors and some have been added as the specification has progressed The original USB specification detailed Standard A and Standard B plugs and receptacles The first engineering change notice to the USB 2 0 specification added
98. the data are plotted part Likewise the amplitude or the periods can be transformed as well Like adjusting the VOLTS DIV and TIME DIV until a clear picture of signal can be obtained However the corresponding numerical value is not exactly in particular when the curve goes up or goes down continuously He Miao PC Oscilloscope USB based 41 University of Hertfordshire School of Electronic Communication and Electrical Engineering BEng Final Year Project Report HE SerialPort Setting 3 z 3 Sele COMFORT Configuration PortHame COM3 r mum WA DT BandRate E DravCurvet DrsnCurve DataBits 7 StopBits m W Down merr 1243434 Send Data EHE SerialPort Setting cm FortHame SS al BaudBate oma EIE Parity z EI lataBitsz I StopBits 12434354 Figure 37 Serial port test According to the project implementation there are there steps for testing UY Connect RS 232 with PCs LI Click on USB button Q Select required COM Port and open it the alert light show green Q Write the random value in the transmit string text box LU Click on the send button Afterwards from Figure 37 above the written number disappears from the Transmit String box and then the same value appear in the Receive String that proves the test is successful He Miao PC Oscilloscope USB based 42 Univers
99. uttons OK MessageBoxIcon Error MessageBoxDefaultButton Buttonl PicAlart BackColor Color Red Exit Sub End Try Select Case CombBaudRat Text the configuration of BaudRate Case 1200 BaudRate 1200 Case 2400 BaudRate 2400 Case 4800 BaudRate 4800 Case 9600 BaudRate 9600 Case 19200 BaudRate 19200 Case 38400 BaudRate 38400 End Select Select Case CombParity Text the configuration of Parity Case NONE s Parity Case ODD Parity gt I0 Ports Parity Odd Case EVEN IO Ports Parity None Parity IO Ports Parity Even End Select select Case CombDataBits Text Case 5 DataBits 5 Case 6 DataBits 6 Case T DataBits 7 Case 8 DataBits 8 End Select Select Case CombStopBits Text the configuration of stopbits Case 1 stopBits IO Ports StopBits One Case LS stopBits IO Ports StopBits OnePointFive Case 2 stopBits IO Ports StopBits Two End Select End With begin to receive data Try With SerialPortl Encoding System Text Encoding ASCII DiscardInBuf fer ReceivedBytesThreshold 1 He Miao PC Oscilloscope USB based 64 Universityof Hertfordshire School of Electronic Communication and Electrical Engineering BEng Final Year Project Report End With Catch ex As Exception MessageBox Show The COM is not existing or occupying Terror MessageBoxButtons OK MessageBoxIcon
100. waveform 11 Trigger It is only needed if the spot moves at an angle rather than horizontally across the screen with no signal connected The trigger circuit is used to delay the time base waveform so that the same section of the input signal is displayed on the screen each time the spot moves across He Miao PC Oscilloscope USB based 48 Universityof Hertfordshire School of Electronic Communication and Electrical Engineering BEng Final Year Project Report The effect of this is to give a stable picture on the oscilloscope screen making it easier to measure and interpret the signal 11 On account of its function in real oscilloscope the button control maybe can be added in the design interface and then add code in the code editor interface such as usercontrol1 data 20 that should work together with the timer control due to delay the time base waveform Function generator As shown in the results by using different math functions the different traces can be spotted over screen Adding button controls as a function generator to show different waves should be a feasible step Like the real oscilloscope below C 200 kHz Function z Generator 5 me melt Xr L So gu 42 c on Dit FREQUENCY RANGE 00 LE Figure 45 Function generator 11 Dual trace Maybe Dual trace can be realized by adding the other loop in the source code that should be similar with the data is plotted part But
101. when TXE is high WR In When taken from a high to a low state WR reads the 8 data lines and writes the byte into the FIFO s transmit buffer Data written to the transmit buffer is sent to the host PC within the TX buffer timeout value default 16mS and placed in the RS 232 buffer opened by the application program Note The FT245BM allows the TX buffer timeout value to be reprogrammed to a value between 1 and 255mS depending on the applicaton requirement also the SND pin can be used to send any remaining data in the TX buffer regardless of the timeout value RD In When pulled low RD takes the 8 data lines from a high impedance state to the current byte in the FIFO s receive buffer Taking RD high returns the data pins to a high impedance state and prepares the next byte if available in the FIFO to be read DC Characteristics Ambient Temperature 0 70 C Electrical level Operating Voltage and Current Parameter Description Mi n fee2 Operating Supply Cure Typ Max Units Conditions ofsa v syv 35 ma noma Operation 50 FIFO IO Pin Characteristics VCCIO 5 0v Parameter Description Min Typ Max Units Conditions Ouiput Votage Hon 44 49 V fisou 2m Ouiputvotagetow 91 or V mam E Input Switching Threshold Input Switching Hysteresis 200 mV LD Le He Miao PC Oscilloscope USB based 71 University of Her
102. y introduced above lt Call range change subroutine the subroutine called range change is the scaling of y axis or the resolution of between unit pixel in the region of window display that will be added in the plot data part as well This part consists of a sub flowchart will be described minutely below lt gt Plot data after the data acquiring over the USB module and then storing in the m DataPot array it should be plotted onto the reference table graphically by using the sine math function This section includes several sub flowcharts which will be discussed in the following part He Miao PC Oscilloscope USB based 22 University of Hertfordshire School of Electronic Communication and Electrical Engineering BEng Final Year Project Report Start At the beginning user can define two parameters to l express the amount of data which intend to show Define the amount of data to currently in the y axis such as m MaxValue 1000 and m MinValue 1000 thereby m range m MaxValue m MinValue And the other correlative parameter is the height of display m range dzee reference table that is display window MESI Height m screen range m_endY m startY m screen range l 25 where the m_screen_range is the range of display window in y axis or the display region in the dy window of data display Hence the scaling of y axis m_screen_range is m range dy m screen range m r
103. ze the two graphs See Appendix A He Miao PC Oscilloscope USB based 38 University of Hertfordshire M S i School of eee and Electrical Engineering BEng Final Year Project Report The following two pictures show the amplitude changes E a vend j d a Figure 33 Oscilloscope simulation amplitude changes When clicked on the zoom in button the amplitude increased as the magnitude decreased that was because the specification of this coordinates system was 0 0 at the top left of the screen Likewise the wave zoomed out as the magnitude increased in Figure 33 Messe WEE E e BS Ee e Es The figure on the left indicates the curve may be drawn outside the reference table when it is zoomed in luckily the programme have already compiled for erasing the redundant lines D pA rued ECTS SB EN Bod BONE Fis Sis BEE EES Figure 34 Special situation of amplitude changes He Miao PC Oscilloscope USB based 39 University of Hertfordshire School of Electronic Communication and Electrical Engineering BEng Final Year Project Report 1247 2 S1352T4 1226 Read Data J FRE D 6253185303 nM MM que Don Read Data Send Da o en Figure 35 Oscilloscope simulation time div On this condition the time control was designed to change the periods of sine wave drawn And the texts on the left

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