rtc_alarm.h File Reference

This file provides API to enable real-time clock FreeRTOS signals or alarms. More...

#include <stdint.h>
#include "FreeRTOS.h"
#include "semphr.h"

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Data Structures
struct	alarm_time_t

Enumerations
enum	alarm_freq_t { everySecond = 0, everyMinute = 1, everyHour = 2, everyDay = 3 }

Functions
void	rtc_alarm_create_recurring (alarm_freq_t freq, SemaphoreHandle_t *pAlarm)
alarm_time_t *	rtc_alarm_create (alarm_time_t time, SemaphoreHandle_t *pAlarm)

Detailed Description

This file provides API to enable real-time clock FreeRTOS signals or alarms.

Enumeration Type Documentation

enum alarm_freq_t

Frequency of a recurring alarm

Enumerator
everySecond
everyMinute
everyHour
everyDay

Function Documentation

alarm_time_t* rtc_alarm_create	(	alarm_time_t	time,
		SemaphoreHandle_t *	pAlarm
	)

Enables alarm at the given

Parameters

time

Postcondition

pAlarm semaphore will be given when RTC time matches the given time.

Returns

alarm_time_t that can be used to modify alarm time

alarm_time_t my_time = { 12, 30, 0 }; // Alarm at 12:30 PM
alarm_time_t *my_alarm_time = rtc_alarm_create(my_time, &my_sem);

// Check for alarm trigger :
if (xSemaphoreTask(my_sem, portMAX_DELAY)) {
    // Do something
}

// You can change the time any time :
my_alarm_time->hour = 13

void rtc_alarm_create_recurring	(	alarm_freq_t	freq,
		SemaphoreHandle_t *	pAlarm
	)

Enables a permanent recurring alarm every second, minute, or hour

Parameters

pAlarm	The signal (semaphore) to give when the alarm triggers
freq	The frequency of the alarm

See also

alarm_freq_t

Note

This is different from rtc_alarm_create() because once you enable this recurring alarm, there is no way to disable it or change it later.