_timeout_handler

Question

I have just started coding in Timers in nrf51822. Here i am not clear with the Timer part. Can anybody explain me how to use timer with use of Event Scheduler. Here in app_timer_create() function i am not clear with app_timer_timeout_handler_t timeout_handle . Want some explanation in timeout_handler how to use it and where to use it and why to use it.

Kosidinma · Accepted Answer

Basically, the timeout handler contains the code to be executed with the associated timer. So a timer set to run once every second will run the timeout handler code once every second.
Here is some example code showing relevant parts for a timer going off every second. As for the scheduler, the Nan-36 documentation states: 
 
 The SDK contains a scheduler module
which provides a mechanism for moving
the handling of events and interrupts
from the interrupt handlers to main
context. This ensures that all
interrupt handlers execute quickly. 
 
 I've only been using this chip for a short while but I hope this helps :) 
 #define ADC_SAMPLING_INTERVAL APP_TIMER_TICKS(1000, APP_TIMER_PRESCALER) /**< Sampling rate for the ADC. Once per second */

#define SCHED_MAX_EVENT_DATA_SIZE sizeof(app_timer_event_t) /**< Maximum size of scheduler events. Note that scheduler BLE stack events do not contain any data, as the events are being pulled from the stack in the event handler. */
#define SCHED_QUEUE_SIZE 10 /**< Maximum number of events in the scheduler queue. */

static app_timer_id_t m_adc_sampling_timer_id; /**<set ADC timer id */

static void adc_sampling_timeout_handler(void * p_context)
{
 adc_1();
}

/**@brief Function for the Timer initialization.
 *
 * @details Initializes the timer module.
 */
static void timers_init(void)
{
 uint32_t err_code;
 // Initialize timer module, making it use the scheduler
 APP_TIMER_INIT(APP_TIMER_PRESCALER, APP_TIMER_MAX_TIMERS, APP_TIMER_OP_QUEUE_SIZE, true);
	err_code = app_timer_create(&m_adc_sampling_timer_id, APP_TIMER_MODE_REPEATED, adc_sampling_timeout_handler);
 APP_ERROR_CHECK(err_code);
}

/**@brief Function for starting timers.
*/
static void timers_start(void)
{
	uint32_t err_code;
	//ADC timer start
	err_code = app_timer_start(m_adc_sampling_timer_id, ADC_SAMPLING_INTERVAL, NULL);
 APP_ERROR_CHECK(err_code);
}

int main(void)
{
 // Initialize
 leds_init();
 timers_init();
 ble_stack_init();
 bond_manager_init();
 scheduler_init(); 
 gap_params_init();
 services_init();
 advertising_init();
 sensor_sim_init();
 conn_params_init();
 sec_params_init();
 // Start execution
 timers_start();
 advertising_start();

 // Enter main loop
 for (;;)
 { 
 app_sched_execute();
 power_manage();
 }
}

_timeout_handler

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