RE: ADC problem

Susheel Nuguru — Fri, 21 Feb 2025 09:06:02 GMT

If you connect P0.03 to GND and still get a non-zero ADC result, the input may be floating, double check if the connection is proper. Make sure you're reading from P0.03 if that's where your test is connected and try to add some delays between samples just for the sanity of the test.

#define ADC_INPUT_PIN NRF_SAADC_INPUT_AIN1  // P0.03

void saadc_init(void)
{
   nrf_saadc_channel_config_t channel_config =
        NRFX_SAADC_DEFAULT_CHANNEL_CONFIG_SE(ADC_INPUT_PIN);
   channel_config.gain = NRF_SAADC_GAIN1_6;   // Ensure correct gain
   channel_config.reference = NRF_SAADC_REFERENCE_INTERNAL; // 0.6V ref

   nrfx_saadc_init(NULL, wacon_adcIrqHandler);
   nrfx_saadc_channel_init(0, &channel_config);
}


nrf_delay_us(5); 
nrfx_saadc_sample_convert(0, &adc_val);