TMS320F2800137: ADC issue with bitfield projects

manoj kumar

Part Number: TMS320F2800137

hi,

i'm using empty bitfield project, writing to the registers, there is a problem with Adc modules it is giving max value of 900 when i short the adc pin to 3.3V.

SetVREF(ADC_ADCA, ADC_INTERNAL, ADC_VREF3P3);

AdcaRegs.ADCCTL2.bit.PRESCALE = 6; //set ADCCLK divider to /4

AdcaRegs.ADCCTL1.bit.ADCPWDNZ = 1; //power up the ADC
AdcaRegs.ADCCTL1.bit.INTPULSEPOS = 1;

function used. what settings am i missing.

over 1 year ago

0 Ibukun Olumuyiwa over 1 year ago

TI__Genius 11011 points

Hi Manoj,

Can I see the entire code? How did you configure the SOC (ADCxSOCCTL)?

Ibukun

0 manoj kumar over 1 year ago in reply to Ibukun Olumuyiwa

Prodigy 110 points

AdcaRegs.ADCSOC0CTL.bit.TRIGSEL= 0 ; //trigger on software
AdcaRegs.ADCSOC0CTL.bit.CHSEL = 2 ; // A2
AdcaRegs.ADCSOC0CTL.bit.ACQPS = 20 ; //

AdcaRegs.ADCSOCFRC1.bit.SOC1=1; //trigger

0 Ibukun Olumuyiwa over 1 year ago in reply to Ibukun Olumuyiwa

TI__Genius 11011 points

Hello Manoj,

A2 is an AGPIO pin (GPIO224). You need to configure it to analog mode before using it as an ADC input:

GpioCtrlRegs.GPHAMSEL.bit.GPIO224 = 1;
AnalogSubsysRegs.AGPIOCTRLH.bit.GPIO224 = 1;

Regards,
Ibukun

0 manoj kumar over 1 year ago in reply to Ibukun Olumuyiwa

Prodigy 110 points

A12/C1 pin, Analog pins also need to configure like this?

0 Ibukun Olumuyiwa over 1 year ago in reply to manoj kumar

TI__Genius 11011 points

No, A12 is an AIO and does not need to be pre-configured by default before using as an ADC input (out of reset). However, note that this pin does have digital input functionality and so it is possible to configure it in digital input mode.

Please refer to the device data sheet for pin descriptions and functions.

Thanks,
Ibukun

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TMS320F2800137: ADC issue with bitfield projects