Arduino LED Traffic Light

Description

This repository contains two versions of a basic traffic light project that simulates a traffic light using red, yellow, and green LEDs connected to an Arduino:

• Arduino IDE version: Uses the Arduino framework and libraries for easy development.
• Embedded C version: Written in pure C, using AVR registers and timers directly for precise timing and control of the LEDs.

Hardware Requirements

• Arduino Uno or compatible board
• Red, Yellow, and Green LEDs
• Resistors (220Ω)
• Breadboard and Jumper Wires

Files in the Repository

Arduino Version

• Path: arduino/traffic_light/traffic_light.ino
• Description: This is the original Arduino IDE project that simulates a traffic light. It controls the red, yellow, and green LEDs connected to pins 9, 10, and 11, using Arduino libraries.

Embedded C Version

• Path: src/
• Description: This version uses AVR libraries and timers in pure C for the same traffic light functionality. No Arduino-specific libraries are used.
  • src/main.c: Main logic file for the traffic light system.
  • src/traffic_light/traffic_light.c and traffic_light.h: Contains the traffic light control logic.
  • src/timer.h: Provides delay functionality using the _delay_ms function from AVR libraries.

How to Use

Arduino IDE Version

1. Connect the red, yellow, and green LEDs to digital pins 9, 10, and 11 on the Arduino, with each LED connected in series with a resistor to ground.
2. Open the arduino/traffic_light/traffic_light.ino file in the Arduino IDE.
3. Select the correct board and port from the Tools menu.
4. Upload the code to your Arduino board.
5. Observe the LEDs cycling through red, yellow, and green to simulate a traffic light.

Embedded C Version (Pure C)

Prerequisites

• GNU AVR Toolchain: Ensure avr-gcc, avr-libc, and avrdude are installed.
• Make: For building the project using the Makefile.

Compilation and Upload Steps

1. Connect the red, yellow, and green LEDs to digital pins 9, 10, and 11 on the Arduino, with each LED connected in series with a resistor to ground.

2. Clone or download the repository and navigate to the root directory.

3. Modify the Makefile: Open the Makefile and update the AVRDUDE_PORT line to use the correct port for your system.

   • For macOS, the port may look like /dev/cu.usbserial-xxxx.
   • For Linux, it could be /dev/ttyUSB0 or /dev/ttyACM0.
   • For Windows, it might be COMx (where x is the COM port number).

   Example:

   AVRDUDE_PORT = /dev/ttyUSB0  # Update this to match your system

4. Run the following commands to compile and upload the program:

   make clean        # Clean any previous build files
   make              # Compile the project and generate the .hex file
   make upload       # Upload the compiled .hex file to your Arduino board

5. Once uploaded, the traffic light simulation will run on your Arduino, with the LEDs cycling through red, yellow, and green automatically.

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Project Demo

Click the image above to watch the project demo video on YouTube.