Porting Project from SDK12.2 to SDK14.1, SAADC issue

[rms]

I had the following setup, two app_timers triggering blocking SAADC reads in the callback functions

app_timer 1000ms triggering 1 Blocking SAADC read (For battery service, default Bluetooth SIG battery service)

ret_code_t err_code;
nrf_saadc_value_t  data_buffer = 0;

nrf_saadc_channel_config_t  channel_config1 =
    NRF_DRV_SAADC_DEFAULT_CHANNEL_CONFIG_SE(NRF_SAADC_INPUT_AIN4);

err_code = nrf_drv_saadc_init(NULL,battery_level_adc_event_handler );
APP_ERROR_CHECK(err_code);

err_code = nrf_drv_saadc_channel_init(SAADC_CHANNEL_BAS, &channel_config1);
APP_ERROR_CHECK(err_code);

err_code = nrf_drv_saadc_sample_convert(SAADC_CHANNEL_BAS, &data_buffer);
APP_ERROR_CHECK(err_code);

nrf_drv_saadc_channel_uninit(SAADC_CHANNEL_BAS);
nrf_drv_saadc_uninit();

//static nrf_saadc_value_t prev_data_buffer = 500;
float battery_in_percent = 0.0;

if(data_buffer > 145)
{
	battery_in_percent = slope * (data_buffer-147);
	if(battery_in_percent > 100)
	{
		battery_in_percent = 100;
	}
	NRF_LOG_RAW_INFO("Battery in percent %d\n", (uint8_t)battery_in_percent);
	//prev_data_buffer = data_buffer;
}
else
{
	battery_in_percent = 0;
}

err_code = ble_bas_battery_level_update(m_bas, (uint8_t)battery_in_percent);           //Send the battery level over BLE

if ((err_code != NRF_SUCCESS) &&
    (err_code != NRF_ERROR_INVALID_STATE) &&
    (err_code != NRF_ERROR_RESOURCES) &&
    (err_code != BLE_ERROR_GATTS_SYS_ATTR_MISSING)
   )
{
    NRF_LOG_ERROR("Battery Service Error: %u\n", err_code);
	APP_ERROR_HANDLER(err_code);                                               //Assert on error
}

app_timer 1000ms triggering 5 Blocking SAADC reads (custom service characteristic), 5 IR sensor connected to multiplexer connected to AIN5, write_linear_array() selects which pin on the multiplexer is being used

    ret_code_t err_code;
enable_linear_array();

nrf_saadc_channel_config_t	channel_config =
	NRF_DRV_SAADC_DEFAULT_CHANNEL_CONFIG_SE(NRF_SAADC_INPUT_AIN5);

err_code = nrf_drv_saadc_init(NULL, saadc_callback);
APP_ERROR_CHECK(err_code);

err_code = nrf_drv_saadc_channel_init(SAADC_CHANNEL, &channel_config);
APP_ERROR_CHECK(err_code);

config_linear_array_out();
uint8_t sample_counter = 0;
nrf_saadc_value_t  data_buffer=0 ;
uint8_t readINflags = 0;

/* Sample 1 */
write_linear_array(sample_counter);
err_code = nrf_drv_saadc_sample_convert(0, &data_buffer);
APP_ERROR_CHECK(err_code);
if(err_code)
	return err_code;

if(data_buffer > IR_SENSOR_THRESHOLD){
	readINflags |= 0b00000001;
}

/* Sample 2*/
sample_counter++;
write_linear_array(sample_counter);
err_code = nrf_drv_saadc_sample_convert(0, &data_buffer);
APP_ERROR_CHECK(err_code);

if(data_buffer > IR_SENSOR_THRESHOLD){
	readINflags |= 0b00000010;
}

/* Sample 3 */
sample_counter++;
write_linear_array(sample_counter);
err_code = nrf_drv_saadc_sample_convert(0, &data_buffer);
APP_ERROR_CHECK(err_code);

if(data_buffer > IR_SENSOR_THRESHOLD){
	readINflags |= 0b00000100;
}

/* Sample 4 */
sample_counter++;
write_linear_array(sample_counter);

err_code = nrf_drv_saadc_sample_convert(0, &data_buffer);
APP_ERROR_CHECK(err_code);

if(data_buffer > IR_SENSOR_THRESHOLD){
	readINflags |= 0b00001000;
}

/* Sample 5 */
sample_counter++;
write_linear_array(sample_counter);

err_code = nrf_drv_saadc_sample_convert(0, &data_buffer);
APP_ERROR_CHECK(err_code);

if(data_buffer > IR_SENSOR_THRESHOLD){
	readINflags |= 0b00010000;
}

disable_linear_array();
nrf_drv_saadc_channel_uninit(SAADC_CHANNEL);
nrf_drv_saadc_uninit();

The battery measurement app_timer is always running, the other one is on demand (if notify happens on custom characteristic) Both characteristics have read and notify properties. For the custom characteristic a read will the code above directly outside the app_timer.

These worked fine with SDK12.2 and SDK13, however recently I started porting the project to SDK14.1 and the following is happening. When debugging there are no errors and I can read the characteristics fine via BLE or occasionally I get an unknown fault at 0x000128A0 or 0x00014CCC. When compiled with -O3 and not in debug, it runs for a while then goes into a reset loop (keeps resetting) after running for a while or after trying to read the custom characteristic.

With app_timers still running and the SAADC portions completely commented out [and the SAADC disabled as module] I have no issues.

[Jørgen Holmefjord]

Are you pausing the always-running timer when you do the on-demand sampling of the SAADC, or make sure that the other timer handler does not try to initialize the SAADC when it is already initialized by the other? If the chip restarts, it have ended up in the error handler, where the default recovery is to reset the chip. If you enable NRF_LOG and defined the preprocessor symbol DEBUG, the error handler in SDK 14.1 should print the error code and info about that caused the function, if you are not able to reproduce it while debugging.