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Problems with the ADC function in the DPLib

MD58785
Prodigy 30 points

Hello,

 

I have some problems with the ADCDRV_1ch funtion. I'm using the DPLIB v3.1 on a piccolo controlSTICK with the blank-template file. 

The PWM works fine so far. 

I've added the following lines to set up the ePWM trigger:

 

EALLOW;

EPwm2Regs.ETSEL.bit.SOCAEN = 1;

EPwm2Regs.ETSEL.bit.SOCASEL = 1;

EPwm2Regs.ETPS.bit.SOCAPRD = 1;

EDIS;

 

and initialize the ADC with:

 

ChSel[0] = 0; // ADC A0

TrigSel[0] = 7; // EPM2 SOCA

ACQPS[0] = 6;

ADC_SOC_CNF(ChSel,TrigSel,ACQPS,1,0);  // Mode 0

 

The problem is that it only converts for one time from the ADC kickstart. Changing to mode 2 (CLA) makes no diffenrence.

 

Any solution to this?

  • 0
    TI__Expert 4120 points

    Hi MD,

    How are you verifying that the ADC only converts one time?

    I noticed you used the ADC_SOC_CNF() function to set ADC channel 1 to trigger ADC interrupt 1.  Are you using it to trigger your ISR?

    Regards,
    Daniel

     

  • 0 in reply to Daniel Chang
    Prodigy 30 points

     

    Hi Daniel,

     

    I observed the ADC result in the debugger, and it changes only once after the kickstart command. Afterwards I can see that the ePWM2 sets the SOCA flag correctly but I still don’t get any new ADC results.


    For triggering the ISR I use the ePWM1 module as it is already configured in the blank template file.


    I managed to get the ADC to work in continuous mode. But I had to change the ADCINTSOCSEL registers from 0xFF to 0x5555 to do so (ADC_SOC_Cnf.c line 79 and 80). Any other ideas how I can get it to work in triggered mode?


    Regards,

    Marc.

     

    Edit:

    I just found out that only the output node from the ADC_DRC_1ch module doesn’t update. The ADCResult register shows the correct value.

    As stated above, I don’t have this problem in continuous mode. Any ideas?

     

     

  • 0 in reply to MD58785
    Prodigy 30 points

    Ok I've found the problem. I've set up the call and run macros for the wrong ADC channel :-/

    Maybe this should be clarified a little bit more in the DPLib documentation, because in step 4 (page 27) two channels are beeing configured, but the macro commands are only written for one of them in the following steps.

  • 0 in reply to MD58785
    TI__Expert 4120 points

    I reviewed the documentation and you are correct.  Step 4 configures both channel 0 and channel 1 but subsequent steps only show channel 1.  I will mention this to the document owner as a revision.

    Glad you were able to get things working.