First changes to the codebase#

Aim of the tutorial#

In this tutorial a multi-instances module from the Waveform Generator library of the UltraZohm project will be used and the output displayed in the GUI.

Requirements#

The following tutorial requires:

Guideline#

  1. For the purpose of this tutorial, multiple instances of the Chirp wave will be used.

  2. Open the uz_global_configuration.h file and look at the #define UZ_WAVEGEN_CHIRP_MAX_INSTANCES number.

    • Currently two instances of this module are allowed. This means, that the uz_wavegen_chirp_init function can only be called twice, before an assertion stops the processor.

    • This is done to ensure a proper static memory allocation for this module. Since allocation memory for 50 instances, when only e.g. three are needed, is wasteful, the max amount of possible instances is limited by this define.

    • This procedure is the same for every multiple instance module (e.g. IP-Core drivers, PI-Controller etc.).

    • For further information see Static memory allocation.

  3. In this tutorial three instances of the Chirp wave will be used. Therefore adjust the number after the define to 3U .

  4. Follow the guideline for an Chrip wave example implementation. Do this procedure three times.

    • Include the header file #include "uz/uz_wavegen/uz_wavegen.h" in the main.h header of the R5 processor (Baremetal).

    • Declare three different configuration structs in the main.c with different values.

    • Initialize three different instances with three separate calls of the uz_wavegen_chirp_init function.

    • Create for the above steps a new case in the initialization_chain switch case and insert it after the init_software case.

  5. After this, your main.c file should look something like this. //.... signals that code has been left out of.

    • The declaration of the three instances outside of the main is necessary, so that they can be accessed by other c-files.

    • Since the config-structs are not needed after initialization, they can be declared local to the main function.

    Listing 1 main.c code after changes. //.... marks left out code.#
     1 // Includes from own files
 2 #include "main.h"
 3
 4 //....
 5 enum init_chain
 6 {
 7    init_assertions = 0,
 8    init_gpios,
 9    init_software,
10    init_chirp,
11    init_ip_cores,
12    print_msg,
13    init_interrupts,
14    infinite_loop
15 };
16 enum init_chain initialization_chain = init_assertions;
17
18 uz_wavegen_chirp* chirp_instance1 = NULL;
19 uz_wavegen_chirp* chirp_instance2 = NULL;
20 uz_wavegen_chirp* chirp_instance3 = NULL;
21
22 int main(void)
23 {
24    int status = UZ_SUCCESS;
25    while (1)
26    {
27       switch (initialization_chain)
28       {
29          //....
30          case init_software:
31             Initialize_Timer();
32             uz_SystemTime_init();
33             JavaScope_initalize(&Global_Data);
34             initialization_chain = init_chirp;
35             break;
36          case init_chirp:;
37             struct uz_wavegen_chirp_config config_chirp1 = {
38                .amplitude = 2.0f,
39                .start_frequency_Hz = 1.0f,
40                .end_frequency_Hz = 10.0f,
41                .duration_sec = 5.0f,
42                .initial_delay_sec = 0.0f,
43                .offset = 0.0f
44             };
45             struct uz_wavegen_chirp_config config_chirp2 = {
46                .amplitude = 3.0f,
47                .start_frequency_Hz = 1.0f,
48                .end_frequency_Hz = 20.0f,
49                .duration_sec = 20.0f,
50                .initial_delay_sec = 5.0f,
51                .offset = 1.0f
52             };
53             struct uz_wavegen_chirp_config config_chirp3 = {
54                .amplitude = 4.0f,
55                .start_frequency_Hz = 1.0f,
56                .end_frequency_Hz = 50.0f,
57                .duration_sec = 30.0f,
58                .initial_delay_sec = 10.0f,
59                .offset = 2.0f
60             };
61             chirp_instance1 = uz_wavegen_chirp_init(config_chirp1);
62             chirp_instance2 = uz_wavegen_chirp_init(config_chirp2);
63             chirp_instance3 = uz_wavegen_chirp_init(config_chirp3);
64             initialization_chain = init_ip_cores;
65             break;
66          case init_ip_cores:
67             //....;
68          default:
69             break;
70       }
71    }
72    return (status);
73 }

  6. Open up the isr.c file of the R5 processor (Baremetal).

    • This file is used to call the the sample functions (i.e. functions which calculate values for the current time step) of the wavegen module.

    • This is done in the ISR and not the main, since the ISR is called with a constant sample time (through an interrupt), which enables the use of discrete time models.

    • The while(1) loop in main.c does not run with a constant sample time.

  7. Declare in the isr.c file the three instances again, but this time with the extern keyword in front.

    • This keyword specifies that the variable is defined in another file. The extern keyword must be applied in all files, in which the variable is used, except in which the variable is initially defined.

    • This only works, if the variable is global, i.e. declared outside the e.g. main-function.

    • It, in essence, allows the variable to be shared over multiple c-files.

  8. Create three global float values, to which the output of the uz_wavegen_chirp_sample can be passed.

  9. Add the three function calls uz_wavegen_chirp_sample for the three instances in the if-statement.

    • This if-statement prevents the code from being executed, unless the UltraZohm is in the Control state.

    • The UZ has four different states (see R5 state machine):

      1. Idle state: Ready LED will blink slowly, all IO and PWM pins are disabled.

      2. Running state: Ready LED will blink fast and the IP and PWM pins are enabled.

      3. Control state: Ready LED will blink fast, Running LED will turn on and the specific code inside the if-statement in the ISR will be executed.

      4. Error state: Error LED turns on, Running and Control state are disabled and the IO and PWM pins get disabled.

  10. Your isr.c should now look similar to this.

    Listing 2 isr.c code after changes. //.... marks left out code.#
     1 //....
 2 // Global variable structure
 3 extern DS_Data Global_Data;
 4
 5 extern uz_wavegen_chirp* chirp_instance1;
 6 extern uz_wavegen_chirp* chirp_instance2;
 7 extern uz_wavegen_chirp* chirp_instance3;
 8 float chirp_output1 = 0.0f;
 9 float chirp_output2 = 0.0f;
10 float chirp_output3 = 0.0f;
11
12 //==============================================================================================================================================================
13 //----------------------------------------------------
14 // INTERRUPT HANDLER FUNCTIONS
15 // - triggered from PL
16 // - start of the control period
17 //----------------------------------------------------
18 static void ReadAllADC();
19
20 void ISR_Control(void *data)
21 {
22    uz_SystemTime_ISR_Tic(); // Reads out the global timer, has to be the first function in the isr
23    ReadAllADC();
24    update_speed_and_position_of_encoder_on_D5(&Global_Data);
25
26    platform_state_t current_state=ultrazohm_state_machine_get_state();
27    if (current_state==control_state)
28    {
29       chirp_output1 = uz_wavegen_chirp_sample(chirp_instance1);
30       chirp_output2 = uz_wavegen_chirp_sample(chirp_instance2);
31       chirp_output3 = uz_wavegen_chirp_sample(chirp_instance3);
32    }
33    uz_PWM_SS_2L_set_duty_cycle(Global_Data.objects.pwm_d1, Global_Data.rasv.halfBridge1DutyCycle, Global_Data.rasv.halfBridge2DutyCycle, Global_Data.rasv.halfBridge3DutyCycle);
34    // Set duty cycles for three-level modulator
35    PWM_3L_SetDutyCycle(Global_Data.rasv.halfBridge1DutyCycle,
36                      Global_Data.rasv.halfBridge2DutyCycle,
37                      Global_Data.rasv.halfBridge3DutyCycle);
38    JavaScope_update(&Global_Data);
39    // Read the timer value at the very end of the ISR to minimize measurement error
40    // This has to be the last function executed in the ISR!
41    uz_SystemTime_ISR_Toc();
42 }
43 //....

  11. To display the different chirp waves on the JavaScope, the javascope.c and javascope.h file will be modified.

  12. Open the javascope.h file and add three new entrys to the JS_OberservableData enum. (e.g. JSO_Chirpwave1, etc.).

    • Here the names for all observable data are stored in an enum.

    • Observable data include all signals which can be displayed in the JavaScope.

    Listing 3 javascope.h code after changes#
     1   #include "APU_RPU_shared.h"
 2
 3   // Do not change the first (zero) and last (end) entries.
 4   enum JS_OberservableData {
 5      JSO_ZEROVALUE=0,
 6      JSO_Chirpwave1,
 7      JSO_Chirpwave2,
 8      JSO_Chirpwave3,
 9      JSO_ISR_ExecTime_us,
10      JSO_ISR_Period_us,
11      JSO_lifecheck,
12      JSO_theta_mech,
13      JSO_ua,
14      JSO_ub,
15      JSO_uc,
16      JSO_ia,
17      JSO_ib,
18      JSO_ic,
19      JSO_id,
20      JSO_iq,
21      JSO_ud,
22      JSO_uq,
23      JSO_Speed_rpm,
24      JSO_LoadSpeed_rpm,
25      JSO_volt_temp,
26      JSO_SoC_init,
27      JSO_Theta_el,
28      JSO_Theta_mech,
29      JSO_LoadTheta_mech,
30      JSO_DeltaTheta_mech,
31      JSO_Wtemp,
32      JSO_Rs_mOhm,
33      JSO_Ld_mH,
34      JSO_Lq_mH,
35      JSO_PsiPM_mVs,
36      JSO_ENDMARKER
37   };

  13. Add to the javascope.c file with the extern keyword the three chirp_output float variables from the isr.c.

  14. In the JavaScope_initalize function add the three new entries to the js_ch_observable array.

    • Here the addresses of the variables are assigned to the specific elements in the js_ch_observable array corresponding to its enum.

    • The value of the variable itself will be automatically updated in the JavaScope_update function (no changes have to be made).

  15. The javascope.c file should look like this now.

    Listing 4 javascope.c code after changes. //.... marks left out code.#
     1 //....
 2 extern float chirp_output1;
 3 extern float chirp_output2;
 4 extern float chirp_output3;
 5
 6 int JavaScope_initalize(DS_Data* data)
 7 {
 8    //....
 9    js_ch_observable[JSO_ISR_ExecTime_us] = &ISR_execution_time_us;
10    js_ch_observable[JSO_lifecheck]        = &lifecheck;
11    js_ch_observable[JSO_ISR_Period_us]    = &ISR_period_us;
12    js_ch_observable[JSO_Chirpwave1]   = &chirp_output1;
13    js_ch_observable[JSO_Chirpwave2]   = &chirp_output2;
14    js_ch_observable[JSO_Chirpwave3]   = &chirp_output3;
15    //....
16 }
17 //....

  16. Build the changes and if no errors exist flash the UZ.

  17. Open the JavaScope and connect it and select the three new signals in the Setup Scope page. Set every other channel to (0) ZeroValue .

    • You can hide the visible channels by clicking on the corresponding entry in the legend of the scope.

    • Clicking on the entry of the legend in the scope again makes that specific channel visible again.

    • Do this for CH4 and CH5 (CH6 to CH20 are hidden by default). This way, no unnecessary lines with ZeroValue are visible.

  18. Press the Enable System and the Enable Control buttons. Now the chirp waves should be visible in the scope.

    ../../../_images/GUI_chirp.png

    Fig. 5 Visible chirp signals#

  19. This concludes the second tutorial.