Pi-Arduino-ESP32 Communication System

🤖 A comprehensive robotics communication framework for Raspberry Pi, Arduino Uno, and ESP32 with motor control via L298N driver

📌 Project Overview

This project provides a complete three-tier communication system that enables a Raspberry Pi to control robotic movements through an Arduino microcontroller and ESP32 module. It's perfect for:

🚀 Robotics enthusiasts
🎓 Educational IoT projects
🔬 DIY home automation systems
🛠️ Prototyping motor control solutions

Made for everyone - fully commented code and detailed documentation for all skill levels!

🔧 System Architecture

┌─────────────────────────┐
│   Raspberry Pi 4        │
│  (Master Controller)    │
│  Sends Commands via     │
│  Serial (USB)           │
└────────────┬────────────┘
             │ USB Cable @ 9600 baud
             ▼
┌─────────────────────────┐
│   Arduino Uno           │
│   (Bridge/Relay)        │
│   Receives commands     │
│   Forwards to ESP32     │
└────────────┬────────────┘
             │ Serial TX/RX @ 9600 baud
             │ (SoftwareSerial Pins 2,3)
             ▼
┌─────────────────────────┐
│   ESP32 Module          │
│   (Motor Controller)    │
│   Controls L298N Driver │
└────────────┬────────────┘
             │ GPIO pins 25-33
             ▼
┌─────────────────────────┐
│   L298N Motor Driver    │
│   Powers DC Motors &    │
│   Servo Motors via      │
│   12V external supply   │
└─────────────────────────┘

📂 Files in This Repository

1. raspberry_pi_controller.py 🐍

Purpose: Master controller for the entire system

Connection: USB serial to Arduino Uno
Features:
- Interactive command menu
- Real-time motor control (forward, backward, left, right, stop)
- Serial communication debugging
- User-friendly interface with emoji feedback
- Graceful shutdown with motor stopping

How to use:

python3 raspberry_pi_controller.py

Available Commands:

f - Move FORWARD
b - Move BACKWARD
l - Turn LEFT
r - Turn RIGHT
s - STOP all motors
q - QUIT program

Requirements:

pip install pyserial

2. arduino_bridge.ino 🔧

Purpose: Bridge communication between Raspberry Pi and ESP32

Receives: Commands from Pi via USB Serial (baud: 9600)
Sends: Commands to ESP32 via SoftwareSerial (baud: 9600)
Features:
- Bidirectional serial communication
- Command validation (only accepts f, b, l, r, s)
- Debug messages for monitoring
- Error handling

Wiring (Arduino Uno):

Arduino Pin	Connection	Purpose
USB Port	Raspberry Pi USB	Serial communication
Pin 2 (RX)	ESP32 TX (GPIO 17)	Receive from ESP32
Pin 3 (TX)	ESP32 RX (GPIO 16)	Send to ESP32
GND	ESP32 GND	Common ground

Upload Instructions:

Connect Arduino to PC via USB
Open Arduino IDE
Select Board: Arduino Uno
Select COM Port
Click Upload

3. esp32_motor_controller.ino 🎮

Purpose: Motor control logic - receives commands and drives motors

Receives: Commands from Arduino via UART (baud: 9600)
Controls: L298N motor driver for DC motors
Features:
- PWM speed control (0-255)
- Differential speed for turning
- Real-time motor monitoring
- Comprehensive debug output

Motor Control Pins (ESP32):

GPIO	Purpose	Motor
27	IN1 (Direction)	Motor A Forward
26	IN2 (Direction)	Motor A Backward
25	IN3 (Direction)	Motor B Forward
33	IN4 (Direction)	Motor B Backward
14	ENA (PWM Speed)	Motor A Speed
32	ENB (PWM Speed)	Motor B Speed

Motor Speeds:

Forward/Backward: 200/255 (Full power)
Turning: 150/255 (Reduced power for precise turns)

L298N Motor Driver Connections:

L298N Pin	ESP32 Pin	Purpose
IN1	GPIO 27	Motor A Forward Control
IN2	GPIO 26	Motor A Backward Control
IN3	GPIO 25	Motor B Forward Control
IN4	GPIO 33	Motor B Backward Control
ENA	GPIO 14	Motor A Speed (PWM)
ENB	GPIO 32	Motor B Speed (PWM)
GND	GND	Common Ground
+12V	12V Battery	Motor Power Supply
OUT1/OUT2	Motor A	DC Motor Connection
OUT3/OUT4	Motor B	DC Motor Connection

🛠️ Hardware Requirements

Essential Components:

🍓 Raspberry Pi 4 (with power supply)
🔴 Arduino Uno (with USB cable)
📱 ESP32 Development Board
🔌 L298N Dual Motor Driver Module
⚙️ 2x DC Motors (or equivalent)
🔋 12V Battery (for motor power)
🧵 Breadboard and jumper wires
🔌 USB cables (Pi power, Arduino programming)

Optional Components:

📦 Servo motors for robotic arms
🎚️ Potentiometer for speed adjustment
💡 LED indicators for motor status
🔊 Buzzer for audio feedback

📋 Complete Wiring Diagram

Power Distribution:

┌─ 5V/3A PSU ──┬──> Raspberry Pi
│              └──> Arduino 5V (optional)
│
└─ 12V Battery ──> L298N GND + 12V

Serial Communication Chain:

Raspberry Pi ──[USB]──> Arduino Uno ──[Serial]──> ESP32
  /dev/ttyACM0         Pins 2,3              GPIO 16,17
   (9600 baud)         SoftwareSerial        UART0
                        (9600 baud)

Motor Connections:

ESP32 GPIOs (27,26,25,33,14,32) ──> L298N (IN1,IN2,IN3,IN4,ENA,ENB)
                                     ↓
                                  Motors (via OUT pins)

🚀 Quick Start Guide

Step 1: Prepare Hardware

Connect all components according to the wiring diagrams above
Ensure all grounds are connected
Test USB connections

Step 2: Upload Arduino Code

Open Arduino IDE
Load arduino_bridge.ino
Upload to Arduino Uno

Step 3: Upload ESP32 Code

Install ESP32 board in Arduino IDE
Load esp32_motor_controller.ino
Upload to ESP32

Step 4: Run Raspberry Pi Controller

Install Python dependencies: pip install pyserial
Run: python3 raspberry_pi_controller.py
Use interactive menu to control motors

💡 How It Works

Command Flow:

1. User enters command in Pi interface (e.g., 'f' for forward)
   ↓
2. Pi sends character 'f' via USB serial to Arduino
   ↓
3. Arduino receives 'f', validates it, forwards to ESP32
   ↓
4. ESP32 receives 'f', executes moveForward() function
   ↓
5. Motor pins (IN1,IN2,IN3,IN4) set to forward direction
   ↓
6. PWM pins (ENA, ENB) set to motor speed (200/255)
   ↓
7. L298N driver receives signals and powers motors
   ↓
8. Motors rotate and robot moves forward! 🚗

Speed Control Logic:

Forward/Backward:

Both motors: 200/255 speed
Result: Straight movement

Left Turn:

Left motor: 150/255 speed (slower)
Right motor: 200/255 speed (normal)
Result: Rotates left

Right Turn:

Left motor: 200/255 speed (normal)
Right motor: 150/255 speed (slower)
Result: Rotates right

🔍 Debugging Tips

Issue: Arduino not connecting

Solution: Check USB cable, run ls /dev/tty* on Pi
Default port: /dev/ttyACM0 or /dev/ttyUSB0

Issue: Motors not moving

Solution: Check L298N power connections (12V battery)
Verify GPIO pin connections match code
Test motor connections directly with battery

Issue: Serial communication errors

Solution: Ensure all baud rates are 9600
Check GND connections between all devices
Verify UART pins (Arduino 2,3 and ESP32 RX/TX)

Debug Mode:

Uncomment debug lines in code to see serial output:

Serial.println("Debug: Motor A speed = " + String(speed));

📚 Code Comments

All code files include:

📝 Section headers with clear descriptions
💬 Inline comments explaining complex logic
📋 Function documentation with parameters
🔗 Wiring reference diagrams
⚠️ Important warnings and notes

Perfect for learning and customization!

🎯 Common Modifications

Increase Motor Speed:

#define MOTOR_FORWARD_SPEED 255  // Maximum (was 200)

Adjust Turning Speed:

#define MOTOR_TURN_SPEED 100     // Tighter turns (was 150)

Change Baud Rate (all three files):

Serial.begin(115200);  // Faster communication (was 9600)

Add Servo Support:

#include <Servo.h>
Servo servo1;
servo1.attach(GPIO_PIN);
servo1.write(90);  // Set position

📖 Additional Resources

🤝 Contributing

Contributions are welcome! Feel free to:

🐛 Report bugs via Issues
💡 Suggest improvements
🔧 Submit pull requests
📝 Improve documentation

📄 License

This project is open-source and available for educational and personal use.

❓ FAQ

Q: Can I use different microcontrollers? A: Yes! Modify pin definitions to match your hardware.

Q: How many motors can I control? A: L298N supports 2 motors. Add more modules for additional motors.

Q: Can I add wireless control? A: Yes! Replace USB with Bluetooth/WiFi modules.

Q: Is this safe for beginners? A: Yes! All code is heavily commented and step-by-step guides provided.

🎉 Getting Started

⭐ Star this repository
🍴 Fork to your account
📥 Clone to your local machine
📖 Follow the Quick Start Guide
🚀 Build amazing robots!

Happy Building! 🤖✨

Name		Name	Last commit message	Last commit date
Latest commit History 8 Commits
README.md		README.md
Samaira(Chatbot).py		Samaira(Chatbot).py
arduino_bridge.ino		arduino_bridge.ino
esp32_motor_controller.ino		esp32_motor_controller.ino
raspberry_pi_controller.py		raspberry_pi_controller.py

Max23012010/pi-arduino-esp32-communication

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