Arduino Relay On/Off Timer with DS3231 RTC

This Arduino-based relay timer uses a DS3231 RTC module to control a relay module according to preset on/off times. It features an LCD display for time visualization and user input via push buttons to modify settings. The EEPROM stores relay on/off schedules for persistence across power cycles.

Features

• Uses a DS3231 RTC module for accurate timekeeping.
• Controls a relay module for scheduled switching.
• LCD display (LiquidCrystal) to show the current time and relay status.
• 4 push buttons (+, -, Set, Mode) to adjust the relay on/off schedule.
• Stores up to 10 relay on/off times in EEPROM.
• Designed for store signboard lighting control to save power by turning off at unnecessary hours.
• Implemented in a real-world store to automate lighting control.

Hardware Requirements

• Arduino board (e.g., Arduino Uno, Nano, etc.)
• DS3231 RTC module
• Relay module
• 16x2 LCD display
• 4 push buttons (+, -, Set, Mode)
• EEPROM (built-in Arduino memory used)
• Power supply suitable for your relay and load
• Connecting wires

Code Overview

The main functionalities include:

• Reading real-time clock (RTC) data from the DS3231.
• Displaying the time and configs on the LCD screen.
• Adjusting relay on/off times using push buttons.
• Storing and retrieving relay schedules from EEPROM.
• Turning the relay on and off automatically based on stored schedules.

Code Snippet

How to Use

1. Connect all components togethor
2. Upload the timer.ino code to the Arduino board.
3. Set up relay on/off times using the push buttons.
4. The system will automatically turn the relay on and off at the configured times.
5. The EEPROM stores schedules, so they remain saved even after power loss.
6. The LCD displays the current time and config settings for relay timing.

Applications

• Store signboard lighting automation to save power.
• Industrial equipment scheduling.
• Home automation projects.

License

This project is licensed under the MIT License - see the LICENSE file for details.