LAUNCHXL-CC1312R1: ADC Sample 2 channels

David Jones

Part Number: LAUNCHXL-CC1312R1
Other Parts Discussed in Thread: SYSCONFIG

I have used an example (see below) and have a single ADC channel being sampled on DIO23 I would like to use my code and sample a second channel on DIO24 I don't think you can do these simultaneously and if not then I would like to sample immediately after the first sample can you please assist

/*
* ======== threadFxn0 ========
* Open an ADC instance and get a sampling result from a one-shot conversion.
*/
void *threadFxn0(void *arg0)
{
ADC_Handle adc;
ADC_Params params;
int_fast16_t res;

ADC_Params_init(&params);
adc = ADC_open(CONFIG_ADC_0, &params);

if (adc == NULL) {
Display_printf(display, 0, 0, "Error initializing CONFIG_ADC_0\n");
while (1);
}

/* Blocking mode conversion */
res = ADC_convert(adc, &adcValue0);

if (res == ADC_STATUS_SUCCESS) {

adcValue0MicroVolt = ADC_convertRawToMicroVolts(adc, adcValue0);

Display_printf(display, 0, 0, "CONFIG_ADC_0 raw result: %d\n", adcValue0);
Display_printf(display, 0, 0, "CONFIG_ADC_0 convert result: %d uV\n",
adcValue0MicroVolt);
}
else {
Display_printf(display, 0, 0, "CONFIG_ADC_0 convert failed\n");
}

ADC_close(adc);

return (NULL);
}

Regards

David

over 3 years ago

0 Marie H over 3 years ago

TI__Guru* 82271 points

Hi David,

What version of the SimpleLink SDK are you using?

Cheers,

Marie H

0 Sid over 3 years ago in reply to Marie H

TI__Mastermind 20412 points

Hi David,

In the ADC driver documentation, please look at the section "Executing multi channel sampling"

https://dev.ti.com/tirex/content/simplelink_cc13xx_cc26xx_sdk_6_10_00_29/docs/drivers/doxygen/html/_a_d_c_8h.html

This should give you a way to perform sampling on two channels.

Regards,

Sid

0 David Jones over 3 years ago in reply to Marie H

Intellectual 820 points

Hi Marie

5.20

0 David Jones over 3 years ago in reply to Sid

Intellectual 820 points

Hi Sid

Thanks for sending me the header file, I have also now done the adc with the buffer please see below.

ADCBuf_Params_init(&adcBufParams);

adcBufHandle = ADCBuf_open(CONFIG_ADCBUF_0, &adcBufParams);
if (adcBufHandle == NULL)
{
while(1);
}

blockingConversion.arg = NULL;
blockingConversion.adcChannel = CONFIG_GPIO_ADCBUF_0_CHANNEL_0_CHANNEL_0;
blockingConversion.sampleBuffer = sampleBufferOne;
blockingConversion.sampleBufferTwo = NULL;
blockingConversion.samplesRequestedCount = ADCSAMPLESIZE;

if (ADCBuf_convert(adcBufHandle, &blockingConversion, 1) != ADCBuf_STATUS_SUCCESS)
{
while(1);
}

ADCBuf_adjustRawValues(adcBufHandle, sampleBufferOne, ADCSAMPLESIZE, CONFIG_GPIO_ADCBUF_0_CHANNEL_0_CHANNEL_0);

ADCBuf_convertAdjustedToMicroVolts(adcBufHandle, CONFIG_GPIO_ADCBUF_0_CHANNEL_0_CHANNEL_0,
sampleBufferOne, microVoltBuffer, ADCSAMPLESIZE);

What is the difference between the header file you sent and the buffer above?, and which is the best one to use?

Regards

David

+1 Sid over 3 years ago in reply to David Jones

TI__Mastermind 20412 points

Hi David,

Depending on our use case, you can choose one of the two. The ADCBUF allows a continuous sampling of a sensor and adds data to a buffer, while the ADC driver's convert API is called every time a signal needs to be sampled and processed.

But for your use case, you seem to benefit from the ADC_convertChain() API provided in the ADC driver to sample multiple signals.

https://dev.ti.com/tirex/content/simplelink_cc13xx_cc26xx_sdk_6_10_00_29/docs/drivers/doxygen/html/_a_d_c_8h.html#a8150c6d87037c8d056ec74c61345d523

Regards,

Sid

0 David Jones over 3 years ago in reply to Sid

Intellectual 820 points

Hi Sid

Thanks for all your help, one question how do I know which I/0 ADC input is being used?

Regards

David

0 Sid over 3 years ago in reply to David Jones

TI__Mastermind 20412 points

This information is available in Sysconfig,

Regards,

Sid

0 David Jones over 3 years ago

Intellectual 820 points

Part Number: LAUNCHXL-CC1312R1

I am just testing the ADC on Sensor Controller Studio, is it going to be possible to use 2 I/0 sampling at 100 Herts Sine and CoSine, and use your C like code to convert to Degrees within the Sensor Controller Studio.

Kind Regards

David

0 David Jones over 3 years ago

Intellectual 820 points

Part Number: LAUNCHXL-CC1312R1

I am having trouble getting the ADC_convertChain working I have attached my code below but I get warnings from the compiler (incompatible parameters) can someone please point out where I am going wrong

ADC_Handle adc[ADC_COUNT];
ADC_Params adcparams;

int_fast16_t res;
uint16_t retValues[ADC_COUNT];
uint8_t i;

ADC_Params_init(&adcparams);
res = ADC_open(adc, &adcparams);

res = ADC_convertChain(adc, retValues, ADC_COUNT);
if (res == ADC_STATUS_SUCCESS)
{
Display_printf(display, 0, 0, "CONFIG_ADC_0 convert result: %d uV",retValues);
}

GPIO_toggle(GPIO_LED_1);

ADC_close(adc);

Regards

David

0 Sid over 3 years ago in reply to David Jones

TI__Mastermind 20412 points

Hi David,

Please can you post the warnings, which line is the warning directed towards?

Regards,

Sid

0 David Jones over 3 years ago in reply to Sid

Intellectual 820 points

Hi Sid

please see below

Regards

David

0 Sid over 3 years ago in reply to David Jones

TI__Mastermind 20412 points

Hi David,

Open the ADC instances individually, and close them individually. ADC_open takes the index of the adc instance and not the handle itself.

Something like this:

    adc[0] = ADC_open(CONFIG_ADC_1, &params);
    adc[1] = ADC_open(CONFIG_ADC_2, &params);

Similarly for ADC_close() which takes a single adc handle as input do the following:

    ADC_close(adc[0]);
    ADC_close(adc[1]);

This should resolve the issue.

Regards,

Sid

0 David Jones over 3 years ago in reply to Sid

Intellectual 820 points

Hi Sid

Do I have to setup another ADC in the config xxx.syscfg, as I have setup CONFIG_ADC_1 which it recognizes, but not CONFIG_ADC_2 as I haven't set it up in the xxx.syscfg

Thank for your help

David