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.

[Susheel Nuguru]

Yes, I ran your code just now and found the problem.

The problem is that you are not initializing timer priority so it is set with default priority of 0 which is not allowed by softdevice.

Initialize your timer3 like below

nrf_drv_timer_config_t timer_cfg = NRF_DRV_TIMER_DEFAULT_CONFIG;

err_code = nrf_drv_timer_init(&m_timer, &timer_cfg, timer_handler);
APP_ERROR_CHECK(err_code);

And you then the timer3 intterupt will be with priority 6 which is allowed by softdevice.

[dchaudet]

Thanks a lot! It was my problem. Now, I've few tasks with adc in IRQ + BLE! Have a good day!