saadc_init fails with NRFX_ASSERT generated from err_code = nrf_drv_saadc_channel_init(0, &channel_config)

[EricDelangis]

I am using SDK 15.3, SES 4.3 and SD 130.  I've added the saadc example code into my code which is comprised of the ble_central, nordic UART and saadc.

I've changed the timer instance from 0 to 1 and 2 because of the softdevice:

static const nrf_drv_timer_t m_timer = NRF_DRV_TIMER_INSTANCE(1);

#define SAMPLES_IN_BUFFER 5
volatile uint8_t state = 1;

static const nrf_drv_timer_t m_timer = NRF_DRV_TIMER_INSTANCE(1); // Eric - changed from 0 to 1 since 0 is used by SD
static nrf_saadc_value_t m_buffer_pool[2][SAMPLES_IN_BUFFER];
static nrf_ppi_channel_t m_ppi_channel;
static uint32_t m_adc_evt_counter;

//  APP_TIMER_DEF(saadc_timer);   // Eric - added this line. Code doesn't seem matter.
void saadc_timer_handler(nrf_timer_event_t event_type, void *p_context) {
  saadc_callback();
  printf("saadc timer timed out");
}

I thought that the app_timers used timer instance 1 and they are working fine. I've also tried timer instance 2 but it didn't solve anything.  

Please tell me what I am missing here.

[Jørgen Holmefjord]

Hi,

How did you declare channel_config? If you get an assert on line 10 of the code snippet you posted, the analog input is not set correctly in the config struct.

Best regards,
Jørgen

[Jørgen Holmefjord]

The SAADC does not take a GPIO pin number as input, you need to use one of the pins in the nrf_saadc_input_t enum. In your case, that should be NRF_SAADC_INPUT_AIN6.