RE: Can't set up timer in couner mode with ppi

DonalHE — Fri, 18 Nov 2016 16:04:43 GMT

Thank you for sharing your solution!

RE: Can't set up timer in couner mode with ppi

Vladimir — Thu, 18 Aug 2016 13:34:00 GMT

Thank's for link. I solved that problem using drivers:

Initialisation:

	nrf_drv_timer_t timer1 = NRF_DRV_TIMER_INSTANCE(2);

	nrf_ppi_channel_t ppi_channel1;

	uint32_t capture_frenq(){
		uint32_t frenq_ = nrf_drv_timer_capture(
					&timer1,
					NRF_TIMER_CC_CHANNEL0
			);
			
		timer1.p_reg->TASKS_CLEAR = 1;
		timer1.p_reg->TASKS_START = 1;
		return frenq_;
	}

	// Void handler
	void timer_void_handler(nrf_timer_event_t event_type, void * p_context){}

	void pin_event_void_handler(nrf_drv_gpiote_pin_t pin, nrf_gpiote_polarity_t action){}


	//Counter only
	void counter_init(void)
	{	
		
		nrf_drv_timer_config_t conf;
		   conf.mode = TIMER_MODE_MODE_Counter;
		   conf.bit_width = TIMER_BITMODE_BITMODE_16Bit;
		   conf.p_context = &timer1;
		   
		APP_ERROR_CHECK(
				   nrf_drv_timer_init(
						   &timer1,
						   &conf,
						   timer_void_handler
		   ));
		   
		nrf_drv_timer_enable(&timer1);
	}

	void gpiote_init(nrf_drv_gpiote_pin_t frenq_counter_pin){
		nrf_drv_gpiote_init();
		
		nrf_drv_gpiote_in_config_t config = GPIOTE_CONFIG_IN_SENSE_HITOLO(true);
		config.pull = NRF_GPIO_PIN_PULLUP;
		
		nrf_drv_gpiote_in_init(frenq_counter_pin, &config, pin_event_void_handler);
		nrf_drv_gpiote_in_event_enable(frenq_counter_pin, true);
	}


	void ppi_init(nrf_drv_gpiote_pin_t frenq_counter_pin){
		uint32_t err_code = NRF_SUCCESS;

		err_code = nrf_drv_ppi_init();
		APP_ERROR_CHECK(err_code);

		err_code = nrf_drv_ppi_channel_alloc(&ppi_channel1);
		APP_ERROR_CHECK(err_code);
		err_code = nrf_drv_ppi_channel_assign(ppi_channel1,
							nrf_drv_gpiote_in_event_addr_get(frenq_counter_pin),
							nrf_drv_timer_task_address_get(&timer1, NRF_TIMER_TASK_COUNT));
		APP_ERROR_CHECK(err_code);
		
		nrf_drv_ppi_channel_enable(ppi_channel1);
	}


	void speedometer_init(nrf_drv_gpiote_pin_t pin){
		counter_init();
		gpiote_init(pin);
		ppi_init(pin);
	}

Application timer for frequency capturing:

void timers_init(void)
{
	uint32_t err_code;
	APP_TIMER_INIT(APP_TIMER_PRESCALER, APP_TIMER_OP_QUEUE_SIZE, false);
	
	err_code = app_timer_create(&speed_timer_id,
								APP_TIMER_MODE_REPEATED,
								speed_meas_handler);
	APP_ERROR_CHECK(err_code);

}

void speed_meas_handler(void * p_context){
	freq_ = capture_freq();
	
}

RE: Can't set up timer in couner mode with ppi

Susheel Nuguru — Wed, 10 Aug 2016 10:41:57 GMT

I haven't tried it using drivers but here is the post that did this without using drivers. Note that TIMER1 and PPI next to it used to stop the TIMER2 after 1 second. In your case you just need to configure GPIOTE->PPI->TIMER2 in counter mode. @adriand has updated the thread with his code.