Why my adc handler is never triggered?

[ndarkness]

Hello,

I am making a battery service to report the battery that is sampled by the SAADC, so far I am am able to compile it and debug it, however I see how my saadc_event_handler_interrupt is never triggered. Which means to me that the ADC never samples the battery, further, after some itereations I get an error of the softdevice handler.

The function that is triggered once the timer is time out( each 5s) is like this

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

    NRF_LOG_INFO("Read value from saadc %d\n",0);
    saadc_init(batt_meas_init);
    err_code = nrf_drv_saadc_sample();
    APP_ERROR_CHECK(err_code);
}

where the method saadc_init() contains the handler saadc_event_handler_interrupt

uint32_t saadc_init(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_event_handler_interrupt);
    //RETURN_IF_ERROR(err_code);

#ifndef DK_BOARD
    nrf_saadc_channel_config_t channel_config =
    NRF_DRV_SAADC_DEFAULT_CHANNEL_CONFIG_SE(nrf_drv_saadc_gpio_to_ain(batt_meas_init.adc_pin_no));
#else
    nrf_saadc_channel_config_t channel_config = NRF_DRV_SAADC_DEFAULT_CHANNEL_CONFIG_SE(batt_meas_init.adc_pin_no);
#endif
    /* Burst enabled to oversample the SAADC. */
    channel_config.burst    = NRF_SAADC_BURST_ENABLED;
    channel_config.gain     = ADC_GAIN;
    channel_config.acq_time = NRF_SAADC_ACQTIME_3US;//NRF_SAADC_ACQTIME_40US;

    err_code = nrf_drv_saadc_channel_init(0, &channel_config);
    //RETURN_IF_ERROR(err_code);

    err_code = nrf_drv_saadc_buffer_convert(m_buffer, ADC_BUF_SIZE);
    //RETURN_IF_ERROR(err_code);

    return M_BATT_STATUS_CODE_SUCCESS;
}



    static void saadc_event_handler_interrupt(nrf_drv_saadc_evt_t const * const p_event)
    {
        uint32_t err_code;
        uint16_t voltage;
    
        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)
        {
            err_code = adc_to_batt_voltage(*p_event->data.done.p_buffer, &voltage);
            APP_ERROR_CHECK(err_code);
    
            err_code = app_sched_event_put((void*)&voltage, sizeof(voltage), batt_event_handler_adc);
            APP_ERROR_CHECK(err_code);
        }
    
        nrf_drv_saadc_uninit();
    }

and finally this last one calls batt_event_handler_adc that writes the read battery voltage.

static void batt_event_handler_adc(void * p_event_data, uint16_t size)
{
    uint32_t err_code;
    m_batt_meas_event_t batt_meas_evt;

    memcpy(&batt_meas_evt.voltage_mv, p_event_data, size);
    batt_meas_evt.valid_voltage = true;

    if (batt_meas_evt.voltage_mv <= batt_meas_init.batt_voltage_limit_low)
    {
        batt_meas_evt.type = M_BATT_MEAS_EVENT_LOW;
    }
    else if (batt_meas_evt.voltage_mv >= batt_meas_init.batt_voltage_limit_full)
    {
        batt_meas_evt.type = M_BATT_MEAS_EVENT_FULL;
    }
    else
    {
        batt_meas_evt.type = M_BATT_MEAS_EVENT_DATA;
    }

    uint8_t battery_level_percent;

    batt_voltage_to_percent(batt_meas_evt.voltage_mv, &battery_level_percent);
    batt_meas_evt.level_percent = battery_level_percent;

    if(m_ble_bas_configured)
    {
        err_code = ble_bas_battery_level_update(&m_bas, battery_level_percent);
        if ((err_code != NRF_SUCCESS) &&
            (err_code != NRF_ERROR_INVALID_STATE) &&
            (err_code != BLE_ERROR_NO_TX_PACKETS) &&
            (err_code != BLE_ERROR_GATTS_SYS_ATTR_MISSING))
        {
            APP_ERROR_HANDLER(err_code);
        }
    }
    else
    {
        m_initial_batt_level_percent = battery_level_percent;
    }

    m_evt_handler(&batt_meas_evt);
}

So a call to saadc_event_handler_interrupt never happens, I have set a breakpoint in that line, and I don't see anything happen.

Any suggestion?

Thanks in advance,

[anasimtiaz]

Why do you call the saadc_init() function every time after 5s? Afaik you only need to config ADC initially.

[ndarkness]

ON the example the do so, I think it is because you have to wake up the ADC (in case it is on low power)

[Sigurd]

It seems that you are using saadc example code from the Thingy SDK. As mentioned in this post I recommend using the SAADC code from the ble_app_proximty example, as this code is a bit simpler, is targeted for the nRF52-DK and also simpler to integrate to other SDK examples. We can continue the discussion in that post.