⏱ Arduino Programmable Timer Switch

An Arduino-based programmable timer switch that allows users to set hours, minutes, and seconds using push buttons and control a relay output.
The system displays all information on a 16×2 I2C LCD and is suitable for automation and timing-based control applications.

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🔧 Features

• Set timer in hours, minutes, and seconds
• User interface using 16×2 I2C LCD
• Button-based navigation (UP, DOWN, SET, MENU)
• Relay control for external loads
• Real-time countdown display
• Manual stop/reset option

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🧠 How It Works

1. System waits for the user to enter the menu.
2. User sets:
   • Hours
   • Minutes
   • Seconds
3. Once confirmed, the relay turns ON.
4. Countdown begins and is displayed on the LCD.
5. After timer completion, relay turns OFF automatically.
6. Timer can be interrupted or reset anytime using buttons.

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🧰 Hardware Required

Component	Quantity
Arduino (UNO / Nano)	1
16×2 LCD (I2C)	1
Push Buttons	4
Relay Module	1
Jumper Wires	As required
Power Supply	1

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🔌 Pin Configuration

Buttons

Function	Arduino Pin
UP	D2
DOWN	D3
SET	D4
MENU	D5

Output

Component	Arduino Pin
Relay	D8

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📚 Libraries Used

Install the following libraries from Arduino Library Manager:

• LiquidCrystal_I2C
• Wire (default Arduino library)

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⚙️ Setup Instructions

1. Connect all components as per pin configuration
2. Install required libraries
3. Open the .ino file in Arduino IDE
4. Select correct Board and Port
5. Upload the code
6. Power the Arduino and start using the timer

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🔧 Pin Diagram

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🧪 Applications

• Appliance automation
• Timed power control
• Lab experiments
• Learning embedded systems
• DIY electronics projects