Using Real Time Clock (RTC) with Mini Ultra Pro

One of the most important feature of the RTC is the capability to set alarm. This allow the scheduling of a specific process or task when a predefined time and date that has been set earlier is reached. The RTCZero library has included an example of using the alarm feature. Open up the example SimpleRTCAlarm and make the similar changes to the code like in the previous SimpleRTC example.

/*
  Simple RTC Alarm for Arduino Zero and MKR1000

  Demonstrates how to set an RTC alarm for the Arduino Zero and MKR1000

  This example code is in the public domain

  http://arduino.cc/en/Tutorial/SimpleRTCAlarm

  created by Arturo Guadalupi <a.guadalupi@arduino.cc>
  25 Sept 2015
  
  modified
  21 Oct 2015
*/

#include <RTCZero.h>

/* Create an rtc object */
RTCZero rtc;
#define Serial SerialUSB  // ***** Add this line of code *****

/* Change these values to set the current initial time */
const byte seconds = 0;
const byte minutes = 0;
const byte hours = 16;

/* Change these values to set the current initial date */
const byte day = 25;
const byte month = 9;
const byte year = 15;

void setup()
{
  while(!SerialUSB);  // ***** Add this line of code *****
  Serial.begin(9600);

  rtc.begin(); // initialize RTC 24H format

  rtc.setTime(hours, minutes, seconds);
  rtc.setDate(day, month, year);

  rtc.setAlarmTime(16, 0, 10);
  rtc.enableAlarm(rtc.MATCH_HHMMSS);
  
  rtc.attachInterrupt(alarmMatch);
}

void loop()
{

}

void alarmMatch()
{
  Serial.println("Alarm Match!");
}

In this example, the alarm is set 10 seconds after start up. Once the alarm time is reached, you should be able to see the “Alarm Match!” message on the serial monitor.