Experiment #3 – Introduction to TI C2000 microcontroller, Code Composer Studio (CCS) and Matlab Graphic User Interface (GUI)

Objectives – The objective of Experiment #3 is to familiarize the students with the TI C2000 microcontroller, Code Composer Studio, and Matlab Graphic User Interface (GUI). Students will design a power electronics control module which can plot the data from the target board through the Integrated Development Environment (IDE). The analog PWM signal data is to be injected from Function Generator.

Integrated Development Environment (IDE)

The concepts of rapid prototyping and digital control techniques in power electronics in the developed laboratory are realized based on using the TI C2000 micro-controller [13] in conjunction with the Matlab/Simulink software based on an integrated development environment. The integrated development environment is a combination of software tools which allows implementation and experimentation processes to be carried out conveniently and interactively both under one single roof. As depicted in Fig. 2, Matlab/Simulink environment is used for the design, optimization, and off-line simulations of the models and power electronic circuits. The Real Time Workshop converts the Simulink model to C programming code [14]. Subsequently, the C code is automatically compiled to the assembly language for the TI C2000 micro-controller, assembled, link-edited, and downloaded. Finally, Matlab Graphical User Interface (GUI) is used to run, tune, and monitor the running process.

Lab equipment

1) Matlab/Simulink 2) Matlab GUI(Graphical User Interface) 3) Code Composer Studio 4) C2000 Microcontroller(TMS320F28035) 5) Blackhawk USB2000 emulator

Lab procedure

A. Building a simulation model in Matlab/Simulink 1. Create a new Simulink model

2. Initializing the Simulink model by deploying the Target Preference Board block to

your Simulink model

If you get this warning window, click “YES”.

3. Configuration of the Target Preference Board If you double click the Target Preference Board block, you will be able to open the configuration window like below. And then, click the Get from IDE button. The Target Preference Board will automatically configure your Simulink model by linking to Code Composer Studio.

IDE Support will show the information of TI C2000 micro-controller, and confirm the micro controller setting by clicking OK button.

4. Save your Simulink model in temporary folder under C drive You should save your Simulink in the temporary folder under C drive to link to Code Composer Studio.

Ex) C:\TEMP\exp2\exp2mdl

5. Designing a power electronics control Simulink model Add the ADC, Rate Transition, Constant, IQN x int32, Data Type Conversion, and To RTDX in your Simulink model.

6. Configuration of the ADC block Open the configuration window of ADC block by double clicking the block, and then configure the ADC block by following the below settings.

7. Configuration of the Rate Transition block Handle transfer of data between ports operating at different rates. Configuration parameters are shown in the below figures.

8. Configuration of the scale factor for the ADC and Constant block Piccolo F 28035 has a built-in 12-bit ADC(Analog to Digital Converter), input of ADC should be regulated between 0 to 3.3 V. And, a division of 0.83 is added to the lower side. According to the input, ADC will convert the analog signals to the 12 bit digital signal. That is, when 3.3 V input is applied to the ADC, it will convert to the maximum digital value, 4095(2^12). When the 0 V is applied to the ADC, it will convert to the minimum digital value, 0. Therefore, converted analog signal should be re-scaled by the scaling factor, 3.3/4086/0.83 = 0.000971.

DSP based power electronic control system is run on the fixed-data calculation method, thus, the constant source block should be configured as the fixed 32 bit integer. The configuration of the constant block is depicted in the below figure.

9. Configuration of the Data Type Conversion block Convert the input to the data type and scaling of the output. Since the RTDX requires the int32 data type, input must be converted to the data type of int32.

10. Configuration of To RTDX block

11. Configuration of simulation parameter

Set the fixed step size at 1e-5 sec and build action as build only.

B. Designing a control interface by using the Matlab Graphic User Interface(GUI) 1. Starting GUI

Or type GUIDE in the command window, and GUIDE Quick Start dialog will pop up in your MATLAB.

2. Creating a new project

Selecting the ‘Blank GUI(default)’, and then click the ‘ok’ button, the GUIDE layout editor will appear in your MATLAB like below.

GUIDE layout has below components in component palette:

: Push Button

: Slider

: Radio Button

: Check Box

: Edit Text

: Static Text

: Pop-up Menu

: List box

: Toggle Button

: Table

: Axes

: Panel

: Button Group

: ActiveX control

3. Designing the control interface of plotting data from the target board

This control interface consists of one Axes, one Edit box, two Push Buttons, and two Static Text. The axes box will plot obtained data from the DSP as well as showing its numerical value on the edit box. Two Push Buttons will be used as Run and Halt respectively. Two Static Texts will be used to label each component. The sample control interface is shown in the below figure.

4. Save the designed control interface, model and m-file under C:\TEMP

5. Editing m-file code of GUI Initializing output plot settings (You may type the below code after line 64) % Initializing output plot settings % set(handles.figure1, 'visible' , 'off' ) axes(handles.axes1); set(handles.axes1, 'xlim' ,[0 100]); set(handles.axes1, 'ylim' ,[-1 5]); set(handles.axes1, 'xlimmode' , 'manual' ); set(handles.axes1, 'ylimmode' , 'manual' ); set(handles.axes1, 'zlimmode' , 'manual' ); set(handles.axes1, 'climmode' , 'manual' ); set(handles.axes1, 'alimmode' , 'manual' ); set(handles.axes1, 'layer' , 'bottom' ); set(handles.axes1, 'nextplot' , 'add' ); xlabel( 'Fixed steps' ); ylabel( 'Analog output(V)' ); % Plot some dummny data first to get axis handles % allNaN = NaN*ones(1,100); plot(allNaN); handles.h1 = line( 'parent' ,handles.axes1);

Initializing CCS settings % Initializing CCS settings % global cc; cc=ticcs; configure(cc.rtdx,1024,4); open(cc.rtdx, 'ochan1' , 'r' ); enable(cc.rtdx, 'ochan1' ); enable(cc.rtdx); cc.rtdx

Plotting data on the Axes of GUI and showing numerical Ydata values on the Edit box. % Read data from Target Board, and plot them on the axes1 % frameSize = 1; xlimit = 100; NumOfFrames = xlimit/frameSize; yLines = handles.h1; set(handles.figure1, 'visible' , 'on' ); r = cc.rtdx; while (isenabled(cc.rtdx)) set(yLines, 'ydata' , allNaN, 'xdata' , [1:xlimit]); pause(1e-5); for k = 1:NumOfFrames if ~ishandle(yLines) return ; end

yAll = get(yLines, 'ydata' ); x = (k-1)*frameSize+1; y = (k-1)*frameSize+frameSize; % Read Data from the Target through RTDX % numMsgs = r.msgcount( 'ochan1' ); if (numMsgs > 0), if (numMsgs > 1), r.flush( 'ochan1' ,numMsgs-1); end yAll(x:y) = readmsg(cc.rtdx, 'ochan1' , 'int32' ); set(handles.dataedit, 'String' ,num2str(yAll(y))); end set(yLines, 'ydata' ,yAll, 'xdata' ,[1:xlimit]); pause(1e-5); end end

Coding for “Run” and “Halt” button % --- Executes on button press in Run. function Run_Callback(hObject, eventdata, handles) % hObject handle to Run (see GCBO) % eventdata reserved - to be defined in a future v ersion of MATLAB % handles structure with handles and user data ( see GUIDATA)

global cc; run(cc);

% --- Executes on button press in Halt. function Halt_Callback(hObject, eventdata, handles) % hObject handle to Halt (see GCBO) % eventdata reserved - to be defined in a future v ersion of MATLAB % handles structure with handles and user data ( see GUIDATA) global cc; halt(cc);

C. Implementation 1. Turn on the TI C2000 micro-controller You must turn on the TI C2000 micro-controller by selecting the USB side of toggle switch.

2. Check the connection between the Matlab and TI C2000 micro-controller Type “ticcs” in the Matlab command window, and you can check the connection of TI C2000 micro-controller with Matlab.

3. Build C code language from simulation model

Users can build the simulation model by clicking the build button in the simulation toolbar.

And then, IDE link links to Code Composer Studio to generate C code. If build is completed, Code Composer Studio must be linked like below.

4. Loading C code on the target board

Since the build action is selected as ‘build’, use must load the C code on the target board manually by selecting ‘load program’ command in the ‘File’ option.

5. Run the m-file You can run the control interface by clicking RUN button of toolbar of m-file.

6. Plotting the PWM waveform in GUI

Note : Analog signal is connected to ADC A0 port for this lab manual