LED Blinking with Serial Communication

Description

This repository contains two versions of a basic project that blinks an LED connected to pin 8 and sends "Hello, World!" over the serial port every second:

• 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 accurate timing and serial communication.

Project Setup

Hardware Requirements

• Arduino board
• LED and 220Ω resistor
• 2 Jumper wires
• Breadboard

Files in the Repository

Arduino Version

• Path: arduino/hello_world/hello_world.ino
• Description: This is the original Arduino IDE project. It blinks an LED connected to pin 8 and sends "Hello, World!" over the serial port every second using Arduino libraries.

Embedded C Version

• Path: src/
• Description: This version uses AVR libraries and timers in pure C for the same functionality. No Arduino-specific libraries are used.
  • src/main.c: Main logic file.
  • src/usart/usart.c and usart.h: Handles serial communication using USART.
  • src/timer/timer.c and timer.h: Handles Timer1 for LED blinking.
  • src/delay/delay.c and delay.h: Provides accurate delay using Timer0.

How to Use

Arduino IDE Version

1. Connect the LED and resistor in series between pin 8 and ground.
2. Open the arduino/sketch/hello_world.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. Open the Serial Monitor at 9600 baud to see the "Hello, World!" message.

Embedded C Version (Pure C)

Prerequisites

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

Compilation and Upload Steps

1. Connect the LED and resistor in series between pin 8 and 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. Open your serial terminal or the Arduino IDE Serial Monitor at 9600 baud to see the "Hello, World!" message being printed every second.