Nrf52 issue with RTC event running GPIOTE Task

[labi]

Hi,

I'm trying to simply toggle a pin with GPIOTE out toggle task from RTC2 CC0 event. Wrote up the following code and checked the registers in system viewer. Everything seems to check out but still not seeing the pin toggle. Any Ideas what I'm missing here? LFCLK is running @ 32.768kHz, app is modified from ble_app_hrs example.

static nrf_ppi_channel_t            m_ppi_channel;
static const nrf_drv_rtc_t          m_rtc = NRF_DRV_RTC_INSTANCE(2);

static void rtc_handler(nrf_drv_rtc_int_type_t int_type)
{
}

static void rtc_config(void)
{
	uint32_t err_code;

	//Initialize RTC instance
	err_code = nrf_drv_rtc_init(&m_rtc, NULL, rtc_handler);
	APP_ERROR_CHECK(err_code);

	/// Trigger CC0 at 500 ms
	err_code = nrf_drv_rtc_cc_set(&m_rtc, 0 , 16383, false);
	APP_ERROR_CHECK(err_code);

	/// Configure gpiote channel to toggle output
	nrf_drv_gpiote_out_config_t db_config = GPIOTE_CONFIG_OUT_TASK_TOGGLE(true);
	err_code = nrf_drv_gpiote_out_init(DEBUG_TOGGLE, &db_config);
	APP_ERROR_CHECK(err_code);
	nrf_drv_gpiote_out_task_enable(DEBUG_TOGGLE);
 
	/// Wire RTC2 CC0 event to gpiote toggle task
	err_code = nrf_drv_ppi_channel_alloc(&m_ppi_channel);
	APP_ERROR_CHECK(err_code);

	uint32_t rtc_cc_event_addr = nrf_drv_rtc_event_address_get(&m_rtc, NRF_RTC_EVENT_COMPARE_0);
	uint32_t gpiote_task_addr = nrf_drv_gpiote_out_task_addr_get(DEBUG_TOGGLE);    
	err_code = nrf_drv_ppi_channel_assign(m_ppi_channel, rtc_cc_event_addr, gpiote_task_addr);
	APP_ERROR_CHECK(err_code);
 
	err_code = nrf_drv_ppi_channel_enable(m_ppi_channel);
	APP_ERROR_CHECK(err_code);
	
	//Power on RTC instance
	nrf_drv_rtc_enable(&m_rtc);
}    

[Ole Bauck]

I see that the documentation says that the p_config parameter can be NULL to use the default config, but in the nrf_drv_rtc_init(..) function it does not seem to check if this is NULL and use the default config in that case. I will mark this as a bug internally.

Can you check if the code works if you use nrf_drv_rtc_config_t config = NRF_DRV_RTC_DEFAULT_CONFIG and pass this as the p_config parameter instead?

[labi]

I tried your workaround, but that didn't work either. In nrf_drv_rtc_init() I see that its checking for the NULL parameter in SDK11 (see below). Perhaps you were looking at a different version of nrf_drv_rtc?

ret_code_t nrf_drv_rtc_init(nrf_drv_rtc_t const * const p_instance,
                        nrf_drv_rtc_config_t const * p_config,
                        nrf_drv_rtc_handler_t handler)
{
if (handler)
{
    m_handlers[p_instance->instance_id] = handler;
}
else
{
    return NRF_ERROR_INVALID_PARAM;
}

if (p_config == NULL)
{
    p_config = &m_default_config[p_instance->instance_id];
}

[Ole Bauck]

I was looking at SDK 12 and 13, I see that in SDK 11 it checks if the p_config is NULL.

[Ole Bauck]

Is the frequency on the timer 32768 KHz?:

#define RTC2_CONFIG_FREQUENCY    32768

I just tested your code and it works. You know that the pin will only toggle once (before the timer overflows)?