Using additional analog sensors in an insta-spin system

Try changing

ADC_setIntSrc(obj->adcHandle,ADC_IntNumber_2,ADC_IntSrc_EOC10);

and in

void DRV_enableAdcInts(DRV_Handle handle)
{
  DRV_Obj *obj = (DRV_Obj *)handle;

  // enable the PIE interrupts associated with the ADC interrupts
  PIE_enableAdcInt(obj->pieHandle,ADC_IntNumber_2);

  // enable the ADC interrupts
  ADC_enableInt(obj->adcHandle,ADC_IntNumber_2);

  // enable the cpu interrupt for ADC interrupts
  CPU_enableInt(obj->cpuHandle,CPU_IntNumber_10);

  return;
} // end of DRV_enableAdcInts() function

Hi Chris,

Thanks for the suggestions, but I think something is still missing. With just the suggestions made above mainISR triggers far too fast, which I'm guessing is because of the following changes that I made which I thought would be sufficient;

in drv_setupADCs;

  ADC_disableInt(obj->adcHandle,ADC_IntNumber_2);
  ADC_setIntMode(obj->adcHandle,ADC_IntNumber_2,ADC_IntMode_ClearFlag);

in drv_initintvectortable;

pie->ADCINT2 = &mainISR;

and, finally, in mainISR;

DRV_acqAdcInt(drvHandle,ADC_IntNumber_2);

With these changes mainISR triggers at the correct frequency, but motor operation is severely worsened and has an audible modulation at around 40-60 Hz. Could this be due to missed/delayed/incorrect SOC triggering?

For my application I don't strictly need to generate an ADC interrupt on SOC 10 complete --- an ADC interrupt on SOC 7 complete (with SOC 8 - SOC 10 still pending) would be fine as long as there is some way to reliably read result registers 8 through 10...

Hi Devin,

Ok, that sounds pretty reasonable. In my application I don't really need to guarantee that I read the k'th ADC sample in the k'th ISR call, it would be fine to read k-1 as well (I'm only checking some *very* slowly-changing temperature probes). OTOH potentially reading an old ADC sample is a pretty ugly solution, so it would definitely be far less of a kludge to wait for the conversion to be completed.

I'm not really sure of the ADC configuration used/needed by instaspin, could you verify that it would be reasonable for me to;

- set up ADC interrupt 2 to trigger on SOC10 (but not enable ADCINT2 in the PIE)

- poll the relevant status bit in mainISR and wait until the conversion is reported as complete

- clear said bit when the conversion is reported as completed.

This would necessitate some changes in the way the SOC's are triggered, without putting to much thought into it at the moment I would think something along the lines of completely disabling SOC triggers in ADCINTSOCSEL1/2. Is ADCINT2 really used for anything once the ADC initialization/calibration is completed? Does instaspin really do/need anything more than a bog-standard linear SOC chain triggered by EPWM1SOCA?

Yeah, that is exactly what I was thinking.

Yes, InstaSPIN only needs ePWM triggered conversions.  You can and should set all the ADCINTSOCSEL fields to 0.   

Thanks for the help Devin, everything seems to be working well. My changes were in the end exactly what you suggested (and posted here for posterity). In DRV_setupAdcs;

// configure the interrupt sources
  ADC_disableInt(obj->adcHandle,ADC_IntNumber_1);
  ADC_setIntMode(obj->adcHandle,ADC_IntNumber_1,ADC_IntMode_ClearFlag);
  ADC_setIntSrc(obj->adcHandle,ADC_IntNumber_1,ADC_IntSrc_EOC7);

  //ADCINT2 is not used to trigger interrupt, it is only used in the ISR
  //triggered by ADCINT1 to check when the conversion is complete
  ADC_disableInt(obj->adcHandle,ADC_IntNumber_2);
  ADC_setIntMode(obj->adcHandle,ADC_IntNumber_2,ADC_IntMode_ClearFlag);
  ADC_setIntSrc(obj->adcHandle,ADC_IntNumber_2,ADC_IntSrc_EOC10);

  //Clear out any residual ADCINT triggered SOC
  ADC_setupSocTrigSrc(obj->adcHandle, ADC_SocNumber_0, ADC_NoIntTriggersSOC);
  --- similarly for all other SOC's ---
  ADC_setupSocTrigSrc(obj->adcHandle, ADC_SocNumber_15, ADC_NoIntTriggersSOC);

in mainISR;

    // convert the insta-spin ADC data
    DRV_readAdcData(drvHandle,&gAdcData);

    // Wait for the low-priority conversions to complete and clear when complete
    while(!AdcRegs.ADCINTFLG.bit.ADCINT2){};
    AdcRegs.ADCINTFLGCLR.bit.ADCINT2 = 1;
    do_stuff_with_adcresreg_8_through_10();

and, finally, in DRV_enableAdcInts;

  // enable the PIE interrupts associated with the ADC interrupts
  // note that ADCINT2 is *not* passed through to the PIE as we only want to poll its status
  PIE_enableAdcInt(obj->pieHandle,ADC_IntNumber_1);


  // enable the relevant ADC interrupts
  ADC_enableInt(obj->adcHandle,ADC_IntNumber_1);
  ADC_enableInt(obj->adcHandle,ADC_IntNumber_2);

  // enable the cpu interrupt for ADC interrupts
  CPU_enableInt(obj->cpuHandle,CPU_IntNumber_10);