📟 Arduino Counter System with EEPROM, LCD, and Relay Control

This project is a digital counting system using an Arduino, equipped with:

• LCD display for live count and limit
• EEPROM storage for saving settings
• Relay for triggering external devices when a set limit is reached
• Buzzer feedback (enable/disable)
• Multiple buttons for user interaction
• Sensor input (e.g., IR beam break, magnetic switch, etc.)

---

🖼️ System Diagram

Diagram showing the wiring and connections of the Arduino Counter System.

---

🔧 Hardware Components

Component	Description
Arduino (Uno/Nano)	Main microcontroller
LCD (I2C 16x2)	Display count and limit
Relay module	Control external load
Buzzer	Optional audible feedback
Push Buttons (x4)	Start/Stop, Reset, Limit +/-
Digital Sensor	Any digital sensor (e.g., IR)

---

🛠️ Pin Configuration

Function	Arduino Pin
Sensor Input	D5
Relay Output	D12
Buzzer Output	D3
Start Button	D6
Reset Button	D7
Increase Limit	D8
Decrease Limit	D9

---

🧠 Functional Overview

✅ Features

• Count Events: Count each time a digital sensor is triggered (active LOW).

• Start/Stop Toggle: Toggle counting with the Start button.

• Set Limit: Adjust limit using Increase/Decrease buttons.

• Reset Options:

  • Short Press Reset: Resets current counter only.
  • Long Press (≥1 sec): Resets both counter and limit.

• EEPROM Storage:

  • Counter value
  • Counter limit
  • Buzzer enable state

• Relay: Turns OFF when the counter reaches the limit.

• Buzzer: Feedback for button presses and events (can be disabled).

---

📖 EEPROM Memory Map

Address	Variable	Size
0-1	counterLimit	2B
2-3	counter	2B
4	buzzerEnabled	1B

---

🖥️ Serial Monitor Commands

Command	Description
b	Toggle buzzer ON/OFF

---

🧪 Example Behavior

1. Start the system – press Start button.

2. Trigger the sensor – each event increments the count.

3. Once count == limit – relay turns OFF, buzzer beeps thrice.

4. Press Reset:

   • Short: Resets counter.
   • Long (≥1s): Resets counter + limit.

5. EEPROM ensures all values are preserved on power loss.

---

📋 Setup Instructions

1. Wire up the components per the pin map.
2. Upload the code to your Arduino.
3. Open the Serial Monitor (9600 baud) for debug info or toggling buzzer.
4. Use the buttons to interact with the system.

---

⚠️ Notes

• Buttons are assumed to be active LOW with INPUT_PULLUP.
• Buzzer and relay are digital outputs.
• Sensor must give LOW when triggered.
• You can expand this system for automation, production counting, or security applications.

---