CCS/TMS320F28379D: How to select ADC1-B2

Simon Ravyts

Intellectual 510 points

Part Number: TMS320F28379D

Tool/software: Code Composer Studio

Hello

I am trying to measure the voltage at pin 31 of the TI Experimenterkit (TMS320F28379D).

Until now, all the other ADC conversions worked fine, using the code below:

    //------------------------------
    //Current measurement in line 1 - SOC0
    //------------------------------
    AdcaRegs.ADCSOC0CTL.bit.CHSEL = SENSE_LEM1;     //SOC0 will convert pin ADC1A0
    AdcaRegs.ADCSOC0CTL.bit.ACQPS = acqps;            //sample window
    AdcaRegs.ADCSOC0CTL.bit.TRIGSEL = 0x05;        //trigger on ePWM1 SOCA, see page 1347/2472 in datasheet for an overview

I am now trying to set up an ADC that measures at pin 31, which should be ADC1-B2, according to the controlcard pinout.

In the reference manual, p 1357/2472, I however do not find this B2; they all refer to the pins as ADCIN0, ADCIN1, ADCIN2, ...and I used these (I guess) for the ADC1-A1 (ADCIN1).

I am however wondering how to select this pin? The B does not stand for the ADC2 right?

Could someone help me out on this?

over 8 years ago

0 Disona over 8 years ago

Genius 3050 points

Hi, Simon
In F28379D there is a new ADC architecture: there are 4 ADCs (A, B, C, D) with 8 inputs each.
And in future, i guess, TI can put as much ADCs as it wants - that's why they don't refer to each ADC separately. Instead they describe one ADC with its 8 inputs, refeereing like "ADCIN1", since all ADC have same structure. For ADC-B this inpur will be "ADCINB1", for example, or whatever you want.

Back to your question: if you want to measure ADCIN1 intput of ADC-B you have to use registers for ADCB - AdcbRegs.ADCSOC0CTL etc. In your post there is a code for "AdcaRegs". Just copy it and change "AdcaRegs" to "AdcbRegs" and the try to run your project.

Hope this helps.

0 Simon Ravyts over 8 years ago in reply to Disona

Intellectual 510 points

Hello Disona

Thanks for your reply :) It becomes more clear to me now.
I checked again and the pin is apparently connected to ADC C-2, so I changed my code to:
AdccRegs.ADCSOC1CTL.bit.CHSEL = SENSE_Vout; //SOC1 will convert pin ADC C2
AdccRegs.ADCSOC1CTL.bit.ACQPS = acqps;
AdccRegs.ADCSOC1CTL.bit.TRIGSEL = 0x05; //Deze staat nu getriggerd op dezelfde als de ingangsspanningsmeting, kan/mag dit?

But in the debug window, I have the impression that it's still not working. All my other ADC results are constantly blinking yellow and updating their measured values but this one does not do anything and has a constant value of 18084. Is it possible that the trigsel needs to be adapted somehow? I am now triggering on EPWM1, SOCA, which works fine for adc A0...

0 Disona over 8 years ago in reply to Simon Ravyts

Genius 3050 points

Hmm...
The code looks fine to me. FYI you can use ADCSOC0CTL for ADC-C. Each ADC has its own SOCCTL registers.
Have you called "AdcSetMode()" function with ADCb arguments in the beginning of your code?

For example, this is how my code looks (checked and tested):

	// Trigger Timer Init
    EPwm4Regs.TBPRD = (CPU_FREQ / 2)* 1000 / ADC_OPS_FREQ / 2 - 1;	// (200 MHz / 2 (EPWM clock is 100 MHz, not 200 MHz)) / 64 kHz / 2(UpDown)

    EPwm4Regs.ETSEL.bit.SOCAEN = 1;		// enable SOCA
    EPwm4Regs.ETSEL.bit.SOCASEL = 1;	// SOC when timer = 0
    EPwm4Regs.ETPS.bit.SOCAPRD = 1;		// generate pulse on 1st event
    EPwm4Regs.TBCTL.bit.CLKDIV = TB_DIV1;
    EPwm4Regs.TBCTL.bit.HSPCLKDIV = TB_DIV1;
    EPwm4Regs.TBCTL.bit.CTRMODE = TB_COUNT_UPDOWN;
	// ADC init
    EALLOW;
    AdcaRegs.ADCCTL2.bit.PRESCALE = 6;                                  //set ADCCLK divider to /4
    AdcSetMode(ADC_ADCA, ADC_RESOLUTION_12BIT, ADC_SIGNALMODE_SINGLE);  // Non-differential signal, 12 bit resolution
    AdcaRegs.ADCCTL1.bit.INTPULSEPOS = 1;                               // Interrupt right after S/H
    AdcaRegs.ADCCTL1.bit.ADCPWDNZ = 1;                                  // Power-up ADC

    AdcbRegs.ADCCTL2.bit.PRESCALE = 6;                                  //set ADCCLK divider to /4
    AdcSetMode(ADC_ADCB, ADC_RESOLUTION_12BIT, ADC_SIGNALMODE_SINGLE);  // Non-differential signal, 12 bit resolution
    AdcbRegs.ADCCTL1.bit.INTPULSEPOS = 1;                               // Interrupt right after S/H
    AdcbRegs.ADCCTL1.bit.ADCPWDNZ = 1;                                  // Power-up ADC

    AdccRegs.ADCCTL2.bit.PRESCALE = 6;                                  //set ADCCLK divider to /4
    AdcSetMode(ADC_ADCC, ADC_RESOLUTION_12BIT, ADC_SIGNALMODE_SINGLE);  // Non-differential signal, 12 bit resolution
    AdccRegs.ADCCTL1.bit.INTPULSEPOS = 1;                               // Interrupt right after S/H
    AdccRegs.ADCCTL1.bit.ADCPWDNZ = 1;                                  // Power-up ADC

    // Setup ADC channels
    AdcaRegs.ADCSOC1CTL.bit.ACQPS = 10;     // Sample-and-Hold Window: 10 cycles
    AdcaRegs.ADCSOC1CTL.bit.CHSEL = 14;    // Channel ADCIN14 --- Udc
    AdcaRegs.ADCSOC1CTL.bit.TRIGSEL = 0xB;  // Trigger - EPwm4

    AdcbRegs.ADCSOC0CTL.bit.ACQPS = 10;     // Sample-and-Hold Window: 10 cycles
    AdcbRegs.ADCSOC0CTL.bit.CHSEL = 2;    // Channel ADCINB2 --- Ib
    AdcbRegs.ADCSOC0CTL.bit.TRIGSEL = 0xB;  // Trigger - EPwm4

    AdccRegs.ADCSOC0CTL.bit.ACQPS = 10;     // Sample-and-Hold Window: 10 cycles
    AdccRegs.ADCSOC0CTL.bit.CHSEL = 2;    // Channel ADCINC2 --- Ia
    AdccRegs.ADCSOC0CTL.bit.TRIGSEL = 0xB;  // Trigger - EPwm4

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CCS/TMS320F28379D: How to select ADC1-B2