SAADC and S140 - NRF PDK

[pbn4]

My code hit weak handler when I try to modify the examples/peripheral/saadc to run with softdevice s140 on nrf82840 PDK. All I did was adding a BLE Stack initialization before calling saadc_init, saadc_sampling_event_init and saadc_sampling_event_enable. With DEBUG enabled it looks like the code is failing at nrf_drv_timer_init but not information is given through log utility.

Here is the ble_stack_init:

static void ble_stack_init(void)
{
    uint32_t err_code;

    nrf_clock_lf_cfg_t clock_lf_cfg = NRF_CLOCK_LFCLKSRC;

    // Initialize the SoftDevice handler module.
    SOFTDEVICE_HANDLER_INIT(&clock_lf_cfg, NULL);

    ble_enable_params_t ble_enable_params;
    err_code = softdevice_enable_get_default_config(NRF_BLE_CENTRAL_LINK_COUNT,
            NRF_BLE_PERIPHERAL_LINK_COUNT,
            &ble_enable_params);
    APP_ERROR_CHECK(err_code);

    //Check the ram settings against the used number of links
    CHECK_RAM_START_ADDR(NRF_BLE_CENTRAL_LINK_COUNT, NRF_BLE_PERIPHERAL_LINK_COUNT);

    // Enable BLE stack.
    ble_enable_params.gatt_enable_params.att_mtu = NRF_BLE_GATT_MAX_MTU_SIZE;

    err_code = softdevice_enable(&ble_enable_params);
    APP_ERROR_CHECK(err_code);

    // Register with the SoftDevice handler module for BLE events.
    err_code = softdevice_ble_evt_handler_set(ble_evt_dispatch);
    APP_ERROR_CHECK(err_code);

    // Register with the SoftDevice handler module for System events.
    err_code = softdevice_sys_evt_handler_set(sys_evt_dispatch);
    APP_ERROR_CHECK(err_code);
}

and the main function:

int main(void)
{
    ret_code_t err_code;

    err_code = NRF_LOG_INIT(NULL);
    APP_ERROR_CHECK(err_code);

    NRF_LOG_INFO("Initializing BLE stack\r\n");

    ble_stack_init();

    saadc_init();
    saadc_sampling_event_init();
    saadc_sampling_event_enable();

    while (1)
    {
        if (NRF_LOG_PROCESS() == false)
        {
            sd_app_evt_wait();
        }
    }
}

It's most likely something related to interruption priorities or resources taken by SD. I use SDK 12.

EDIT: I also should mention that I like the approach with PPI (Timer -> SAADC), so that timer triggers adc sampling task and in the result I have a continuous sampling with some specified interval (miliseconds).

[Ole Bauck]

Have you changed the timer instance to use another timer than TIMER0?

static const nrf_drv_timer_t m_timer = NRF_DRV_TIMER_INSTANCE(0);

TIMER0 is used by the SoftDevice and cannot be used by the application, see here (SoftDevice S132, but also applies to S140). Using TIMER0 may lead to hardfault or SoftDevice assert. You can use any of the other timers (1 through 4).