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Reference

TimeAlarms Library

TimeAlarms, by Michael Margolis, runs functions at specific times. It is means to be used together with the Time library

Download: Included with the Teensyduino Installer
Latest Developments on TimeAlarms

Hardware Requirements

TimeAlarms does not require any special hardware, because it uses the time and date provided by the Time library.

Creating Alarms

Alarms are used to call a function at a specific time of the day.

Alarm.alarmRepeat(hours, minutes, seconds, function);

Create an alarm that will call a function every day at a particular time.

Alarm.alarmRepeat(dayofweek, hours, minutes, seconds, function);

Create an alarm that will call a function every week on a specific day at a particular time.
"dayofweek" can be dowSunday, dowMonday, dowTuesday, dowWednesday, dowThursday, dowFriday, or dowSaturday.

Alarm.alarmOnce(hours, minutes, seconds, function);

Create an alarm that will call a function tomorrow at a particular time.

Alarm.alarmOnce(dayofweek, hours, minutes, seconds, function);

Create an alarm that will call a function once, at specific day and time.

Creating Timers

Timers call a function at regular intervals.

Alarm.timerRepeat(seconds, function);

Create a timer that will call a function every at an interval of "seconds".

Alarm.timerOnce(seconds, function);

Create a timer that will call a function once in "seconds".

Normal Running Usage

Alarm.delay(milliseconds);

Alarms and Timers are only checks and their functions called when you use this delay function. You can pass 0 for minimal delay. This delay should be used instead of the normal Arduino delay(), for timely processing of alarms and timers.

Example Program

You can open this example from File > Examples > TimeAlarms > TimeAlarmExample.

/*
 * TimeAlarmExample.pde
 *
 * This example calls alarm functions at 8:30 am and at 5:45 pm (17:45)
 * and simulates turning lights on at night and off in the morning
 * A weekly timer is set for Saturdays at 8:30:30
 *
 * A timer is called every 15 seconds
 * Another timer is called once only after 10 seconds
 *
 * At startup the time is set to Jan 1 2011  8:29 am
 */
 
#include <Time.h>
#include <TimeAlarms.h>

void setup()
{
  Serial.begin(9600);
  setTime(8,29,0,1,1,11); // set time to Saturday 8:29:00am Jan 1 2011
  // create the alarms 
  Alarm.alarmRepeat(8,30,0, MorningAlarm);  // 8:30am every day
  Alarm.alarmRepeat(17,45,0,EveningAlarm);  // 5:45pm every day 
  Alarm.alarmRepeat(dowSaturday,8,30,30,WeeklyAlarm);  // 8:30:30 every Saturday 

 
  Alarm.timerRepeat(15, Repeats);            // timer for every 15 seconds    
  Alarm.timerOnce(10, OnceOnly);             // called once after 10 seconds 
}

void  loop(){  
  digitalClockDisplay();
  Alarm.delay(1000); // wait one second between clock display
}

// functions to be called when an alarm triggers:
void MorningAlarm(){
  Serial.println("Alarm: - turn lights off");    
}

void EveningAlarm(){
  Serial.println("Alarm: - turn lights on");           
}

void WeeklyAlarm(){
  Serial.println("Alarm: - its Monday Morning");      
}

void ExplicitAlarm(){
  Serial.println("Alarm: - this triggers only at the given date and time");       
}

void Repeats(){
  Serial.println("15 second timer");         
}

void OnceOnly(){
  Serial.println("This timer only triggers once");  
}

void digitalClockDisplay()
{
  // digital clock display of the time
  Serial.print(hour());
  printDigits(minute());
  printDigits(second());
  Serial.println(); 
}

void printDigits(int digits)
{
  Serial.print(":");
  if(digits < 10)
    Serial.print('0');
  Serial.print(digits);
}