Why does my SAADC hang on calibration?

[ndarkness]

Hello,

I am having an issue with my SAADC, it seems to hang while calibrating. The flow of my app is as follows, on my main the SAADC is started with saadc_start() , where a calibration happens and I don't get a hanging. Afterwards on the handler of the SAADC I desinitialize the SAADC. Later, I have my battery service (battery_level_update()) that will restart the SAADC in order to take a sample and then while calibrating, the SAADC hangs waiting for calibration outcome.

Any advise why does this occur?

Thanks

PS: I am using SDK12.2 with s132v3

void saadc_handler_interrupt(nrf_drv_saadc_evt_t const * const p_event)
{
    uint32_t err_code;
    uint16_t voltage_mV;
    nrf_saadc_value_t adc_result;
    uint16_t tmp_voltage;
    float    adc_gain;

    NRF_LOG_INFO("SAADC interruption\n");

    if (p_event->type == NRF_DRV_SAADC_EVT_CALIBRATEDONE)
    {
        m_adc_cal_in_progress = false;
    }
    else if (p_event->type == NRF_DRV_SAADC_EVT_DONE)
    {
        adc_result = (float) p_event->data.done.p_buffer[0];
        err_code = nrf_drv_saadc_buffer_convert(p_event->data.done.p_buffer, 1);
        APP_ERROR_CHECK(err_code);

        err_code = adc_gain_enum_to_real_gain(ADC_GAIN, &adc_gain);
        APP_ERROR_CHECK(err_code);


        // calling the function that converts the adc reading adc_result into a voltage in mV
        err_code = adc_to_batt_voltage(adc_result, &voltage_mV);
        APP_ERROR_CHECK(err_code);
        
        NRF_LOG_INFO("Read value from saadc %d [mV]\n",voltage_mV);
        //calling the function that will send the battery voltage reading to the BLE stack
        batt_event_handler_adc(voltage_mV);
        
    }
    
    //TODO: disble saadc when not used
//    NRF_LOG_INFO("Disabling SAADC...\n");
//    nrf_drv_saadc_uninit();

}

static uint32_t saadc_calibrate( nrf_drv_saadc_config_t saadc_config)
{
    uint32_t err_code;

    m_adc_cal_in_progress = true;
    err_code = nrf_drv_saadc_calibrate_offset();
    APP_ERROR_CHECK(err_code);

    while(m_adc_cal_in_progress)
    {
        /* Wait for SAADC calibration to finish. */
    }

    return M_BATT_STATUS_CODE_SUCCESS;
}

static uint32_t saadc_start(batt_meas_param_t batt_meas_init)
{
    uint32_t err_code;

   
    nrf_drv_saadc_config_t saadc_config = NRF_DRV_SAADC_DEFAULT_CONFIG;

    err_code = nrf_drv_saadc_init(&saadc_config, saadc_handler_interrupt);
    APP_ERROR_CHECK(err_code);

    // we calibrate the SAADC before configuring it
    err_code = saadc_calibrate(saadc_config);
    APP_ERROR_CHECK(err_code);


    nrf_saadc_channel_config_t channel_config = NRF_DRV_SAADC_DEFAULT_CHANNEL_CONFIG_SE(batt_meas_init.adc_pin_no);

    channel_config.burst    = NRF_SAADC_BURST_ENABLED;
    channel_config.gain     = ADC_GAIN;
    //channel_config.acq_time = NRF_SAADC_ACQTIME_3US;

    err_code = nrf_drv_saadc_channel_init(0, &channel_config);
    APP_ERROR_CHECK(err_code);
    err_code = nrf_drv_saadc_buffer_convert(m_buffer, ADC_BUF_SIZE);
    APP_ERROR_CHECK(err_code);

     return M_BATT_STATUS_CODE_SUCCESS;
}


void battery_level_update(void)
{
    uint32_t err_code;
    uint8_t  battery_level;

    nrf_saadc_event_t  saadc_event;
    nrf_saadc_event_check(saadc_event);
    
    NRF_LOG_INFO("Battery Level update interruption\r\n");

    err_code = saadc_start(batt_meas_init);
    APP_ERROR_CHECK(err_code);

    err_code = nrf_drv_saadc_sample();
    APP_ERROR_CHECK(err_code);
    

}

[Jørgen Holmefjord]

Can you try updating the SAADC driver to the one included in SDK 13.0.0 or above? There was some issues with the driver in SDK 12.x.0. You should be able to copy the files nrf_drv_saadc.c/.h directly from SDK 13.0.0 to SDK 12.2.0.