In this lesson, we have seven projects in one. We learn how to use the DS1307 Real-Time Clock (RTC) module to build a clock using Arduino.

This is project 5: Unlimited Alarm with Relay. This code is designed to have unlimited alarms so you can control multiple devices at different times. We defined an output pin for each alarm to turn it ON or OFF. Each alarm can have a title to identify it, and it will be printed on the serial monitor.