Arduino - SleepRTCAlarm

Sleep RTC Alarm

This example demonstrate how to use the RTC library methods in order to wake up from the standby mode.

Hardware Required


Only your Arduino Board is needed for this example.

ArduinoZero bb

image developed using Fritzing. For more circuit examples, see the Fritzing project page



  Sleep RTC Alarm for Arduino Zero

  Demonstrates the use an alarm to wake up an Arduino zero from Standby mode

  This example code is in the public domain

  created by Arturo Guadalupi

  17 Nov 2015


  01 Mar 2016


  If you use this sketch with a MKR1000 you will see no output on the serial monitor.

  This happens because the USB clock is stopped so it the USB connection is stopped too.

  **To see again the USB port you have to double tap on the reset button!**


#include <RTCZero.h>

/* Create an rtc object */

RTCZero rtc;

/* Change these values to set the current initial time */

const byte seconds = 0;

const byte minutes = 00;

const byte hours = 17;

/* Change these values to set the current initial date */

const byte day = 17;

const byte month = 11;

const byte year = 15;

void setup()


  digitalWrite(LED_BUILTIN, LOW);


  rtc.setTime(hours, minutes, seconds);

  rtc.setDate(day, month, year);

  rtc.setAlarmTime(17, 00, 10);




void loop()

  rtc.standbyMode();    // Sleep until next alarm match

void alarmMatch()

  digitalWrite(LED_BUILTIN, HIGH);