Synchronous Serial Communication (Python & Arduino)

This project demonstrates a synchronous communication handshake between a computer (running Python) and an Arduino microcontroller. The Python script sends a command, and the Arduino processes it and returns a response.

📂 Project Structure

• synchronous.py: The Python script that acts as the "Master". It sends input commands and waits for a reply.
• synchronous.ino: The Arduino firmware that acts as the "Slave". It listens for commands and echoes a status back.

🛠 Prerequisites

Hardware

• Arduino Board (Uno, Nano, Mega, etc.)
• USB Cable

Software

• Python 3.x
• Arduino IDE

Python Libraries

You need the pyserial library to access the USB ports.

pip install pyserial

⚙️ Configuration

1. Arduino Setup

1. Open synchronous.ino in the Arduino IDE.
2. Connect your Arduino to the computer.
3. Select your Board and Port in Tools > Board and Tools > Port.
4. Upload the code.
5. Important: Note the Port name (e.g., COM6 or /dev/ttyUSB0) shown in the IDE.

2. Python Setup

1. Open synchronous.py in your code editor.
2. Locate the configuration section at the top:

   # Configuration
   ARDUINO_PORT = "COM6"  # <-- Change this to your Port
   BAUD_RATE = 9600

3. Update ARDUINO_PORT to match the port you found in the Arduino IDE.

🚀 How to Run

1. Close the Arduino IDE Serial Monitor.
   • Note: The serial port can only be used by one program at a time. If the IDE is connected, Python cannot connect.
2. Run the Python script via terminal:

   python synchronous.py

3. Wait for the initialization message:

   Connected to COM6 at 9600 baud.
   Waiting for Arduino to reset...
   Ready to send commands.
   

4. Type a command (e.g., "Hello") and press Enter.

🐛 Troubleshooting

Error	Solution
SerialException: Access is denied	Another program (like Cura or Arduino Serial Monitor) is using the port. Close them.
No response from Arduino	Check if the BAUD_RATE in Python (9600) matches Serial.begin(9600) in the Arduino code.
Garbage characters (?)	Baud rate mismatch. Ensure both are set to 9600.

📄 License

This project is open-source. Feel free to modify it for your own needs.

Author: Rubens Braz.