FreeRTOS with BLE and ADC (nrf52)

[dchaudet]

Hi,

I'm looking for an example which combines FreeRTOS, BLE and ADC on nrf52 board(10040). I'm able to have FreeRTOS with BLE, FreeRTOS with ADC but not everything together.

I have a conflict in using timer. FreeRTOS clock is launch via nrf_drv_clock_init(). BLE uses app_timer functionnalities. And ADC needs a timer for ppi configuration. I don't understand how the differents timers can coexist. On the differents example I found in github, there is no config with all these constants defined :

#define CLOCK_ENABLED  //Used for FreeRTOS clock
#define TIMER_ENABLED   //Used to enabled Timer 0
#define TIMER3_ENABLED //Timer used for adc (via ppi)

Is anyone has an example. It could help me to understand my misunderstanding of the way it works.

[dchaudet]

Thanks for the quick answer. I agree, I can't use TIMER0 + RTC0 if I use BLE. My bad! I updated my post. I defined TIMER3. This is what I did for now :

 - Initialize clock at the beginning of my program (before using any peripheral).
 - Initialize the saadc module with ppi :

static const nrf_drv_timer_t   m_timer = NRF_DRV_TIMER_INSTANCE(3);

ret_code_t err_code;
err_code = nrf_drv_ppi_init();
APP_ERROR_CHECK(err_code);

err_code = nrf_drv_timer_init(&m_timer, NULL, 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, 1000);
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_event_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_event_addr);
APP_ERROR_CHECK(err_code);

error_code = nrf_drv_saadc_init(NULL, adc_handler);

When I don't initialize adc, ble works fine. I don't understand in which part, adc configuration does conflicts. Is there a problem on my way to initialize ppi?