Trigger saadc sample task with ppi on a ble rscs profile

Question

Hi everyone, 
 Maybe my problem has already been solved in another discussion, if so, I haven't found it yet ! 
 
 I'm programming on a external board using nrf52832. 
 I'm developping a program based on the ble_app_rscs_ example of the SDK 14.2. 
 
 I'm trying to add saadc triggered by ppi as in the example of the SDK (peripheral -> saadc) 
 
 Here is my problem, where I try to trigger the saadc with ppi, the application get stucked and do not advertise. 
 But when I trigger the saadc manualy with nrf_drv_saadc_sample(), and remove those two lines : 
 saadc_sampling_event_init();
saadc_sampling_event_enable(); 
 it works just fine ! 
 So the problem comes from those two functions. 
 
 Here is my main function : 
 /**@brief Function for application main entry.
 */
int main(void)
{
 bool erase_bonds;

 //led init
 nrf_gpio_cfg_output(12);
 nrf_gpio_cfg_output(15);
 nrf_gpio_cfg_output(17);
 
 nrf_gpio_pin_set(12); //Green led ON
 nrf_gpio_pin_set(15); //Blue led OFF
 nrf_gpio_pin_set(17); //Red led OFF

 
 // Initialize.
 log_init();
 timers_init();
 buttons_leds_init(&erase_bonds);
 ble_stack_init();
 gap_params_init();
 gatt_init();
 advertising_init();
 services_init();
 sensor_simulator_init();
 conn_params_init();
 peer_manager_init();

 //Initialize the TWI connection
 twi_init();
 fn_configure_LIS2DH_accelero();

 //Initialize the SAADC
 saadc_init();
 saadc_sampling_event_init();
 saadc_sampling_event_enable(); 

 // Start execution.
 NRF_LOG_INFO("Running Speed and Cadence example started.");
 application_timers_start();

 advertising_start(erase_bonds);

 // Enter main loop.
 for (;;)
 {
 if (NRF_LOG_PROCESS() == false)
 {
 power_manage();
 }
 }
} 
 
 I use the same saadc functions as in the nordic saadc example : 
 //SAADC
void timer_handler(nrf_timer_event_t event_type, void * p_context)
{
 
}

void saadc_sampling_event_init(void)
{
 ret_code_t err_code;

 err_code = nrf_drv_ppi_init();
 APP_ERROR_CHECK(err_code);

 nrf_drv_timer_config_t timer_cfg = NRF_DRV_TIMER_DEFAULT_CONFIG;
 timer_cfg.bit_width = NRF_TIMER_BIT_WIDTH_32;
 err_code = nrf_drv_timer_init(&m_timer, &timer_cfg, timer_handler);
 APP_ERROR_CHECK(err_code);

 /* setup m_timer for compare event every 400ms */
 uint32_t ticks = nrf_drv_timer_ms_to_ticks(&m_timer, 40);	//Oliver : Sampling rate = 2,5Hz
 nrf_drv_timer_extended_compare(&m_timer,
 NRF_TIMER_CC_CHANNEL0,
 ticks,
 NRF_TIMER_SHORT_COMPARE0_CLEAR_MASK,
 false);
 nrf_drv_timer_enable(&m_timer);

 uint32_t timer_compare_event_addr = nrf_drv_timer_compare_event_address_get(&m_timer,
 NRF_TIMER_CC_CHANNEL0);
 uint32_t saadc_sample_task_addr = nrf_drv_saadc_sample_task_get();

 /* setup ppi channel so that timer compare event is triggering sample task in SAADC */
 err_code = nrf_drv_ppi_channel_alloc(&m_ppi_channel);
 APP_ERROR_CHECK(err_code);

 err_code = nrf_drv_ppi_channel_assign(m_ppi_channel,
 timer_compare_event_addr,
 saadc_sample_task_addr);
 APP_ERROR_CHECK(err_code);
}


void saadc_sampling_event_enable(void)
{
 ret_code_t err_code = nrf_drv_ppi_channel_enable(m_ppi_channel);

 APP_ERROR_CHECK(err_code);
}


void saadc_callback(nrf_drv_saadc_evt_t const * p_event)
{
 if (p_event->type == NRF_DRV_SAADC_EVT_DONE)
 {
 ret_code_t err_code;

 err_code = nrf_drv_saadc_buffer_convert(p_event->data.done.p_buffer, SAMPLES_IN_BUFFER);
 APP_ERROR_CHECK(err_code);
 
 
 my_saadc_value = p_event->data.done.p_buffer[0];
 }
}

void saadc_init(void)
{
 ret_code_t err_code;
 nrf_saadc_channel_config_t channel_config =
 NRF_DRV_SAADC_DEFAULT_CHANNEL_CONFIG_SE(NRF_SAADC_INPUT_AIN7); //NRF_SAADC_INPUT_AIN3); //FB NRF_SAADC_INPUT_AIN0);
 
 channel_config.gain = NRF_SAADC_GAIN2; //FB change gain from 1/6 (default) to 2

 err_code = nrf_drv_saadc_init(NULL, saadc_callback);
 APP_ERROR_CHECK(err_code);

 err_code = nrf_drv_saadc_channel_init(0, &channel_config);
 APP_ERROR_CHECK(err_code);

 err_code = nrf_drv_saadc_buffer_convert(m_buffer_pool[0], SAMPLES_IN_BUFFER);
 APP_ERROR_CHECK(err_code);

 err_code = nrf_drv_saadc_buffer_convert(m_buffer_pool[1], SAMPLES_IN_BUFFER);
 APP_ERROR_CHECK(err_code);

} 
 
 And I've included as in the saadc example : 
 //SAADC
#define SAMPLES_IN_BUFFER 1
volatile uint8_t state = 1;

static const nrf_drv_timer_t m_timer = NRF_DRV_TIMER_INSTANCE(1);
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;
nrf_saadc_value_t my_saadc_value = 0; 
 
 I've modified the sdk_config.h file in order to enable the saadc, the nrf_drv_timer1 and the ppi function. 
 
 So i don't understand wher the problem is, I suspect it to be in the ppi... 
 
 Can someone help me to solve the problem ? 
 
 Thank you, 
 Regards, 
 Olivier