The flexibility and affordability of Raspberry Pi make it an excellent choice for robotics enthusiasts. In this guide, we’ll walk you through the process of building a basic robot using a Raspberry Pi. By the end of this tutorial, you’ll have the foundational skills to develop more advanced robotics projects.

Components Required

To build your first Raspberry Pi-powered robot, you’ll need the following components:

  • Raspberry Pi (Model 3B+ or 4 recommended)
  • Motor driver (L298N recommended)
  • Chassis with two DC motors and wheels
  • Battery pack
  • Jumper wires
  • Ultrasonic Sensor (HC-SR04)

Step 1: Setting Up the Raspberry Pi

Start by setting up your Raspberry Pi with the Raspberry Pi OS. You can refer to the official Raspberry Pi documentation for detailed installation instructions. Ensure you have network access and SSH enabled.

Step 2: Installing Python Libraries

Robot programming in Raspberry Pi often requires special libraries. Open a terminal and install the required libraries using pip:

sudo apt update
sudo apt install python3-pip
pip3 install RPi.GPIO
pip3 install adafruit-circuitpython-hcsr04

Step 3: Connecting the Motor Driver

The L298N motor driver is used to control the direction and speed of the motors. Connect your Raspberry Pi GPIO pins to the motor driver as follows:

  • IN1 to GPIO17
  • IN2 to GPIO18
  • IN3 to GPIO27
  • IN4 to GPIO22

Step 4: Wiring the Ultrasonic Sensor

The ultrasonic sensor helps the robot detect obstacles. Connect your HC-SR04 sensor to the Raspberry Pi:

  • VCC to 5V
  • TRIG to GPIO23
  • ECHO to GPIO24
  • GND to Ground

Step 5: Writing the Basic Robot Code

Here’s a simple Python script that moves the robot forward until it detects an obstacle, then stops:

import RPi.GPIO as GPIO
import time
from adafruit_hcsr04 import HCSR04

# Setup
GPIO.setmode(GPIO.BCM)
GPIO.setup(17, GPIO.OUT)
GPIO.setup(18, GPIO.OUT)
GPIO.setup(27, GPIO.OUT)
GPIO.setup(22, GPIO.OUT)

sonar = HCSR04(trigger_pin=23, echo_pin=24)

# Function to move the robot

def move_forward():
    GPIO.output(17, True)
    GPIO.output(18, False)
    GPIO.output(27, True)
    GPIO.output(22, False)

# Function to stop the robot

def stop_robot():
    GPIO.output(17, False)
    GPIO.output(18, False)
    GPIO.output(27, False)
    GPIO.output(22, False)

try:
    while True:
        distance = sonar.distance
        print(f"Distance: {distance:.1f} cm")
        if distance < 30:  # stop if obstacle is within 30 cm
            stop_robot()
        else:
            move_forward()
        time.sleep(0.1)
except KeyboardInterrupt:
    GPIO.cleanup()

Step 6: Running Your Robot

Save your code as simple_robot.py and ensure all your hardware connections are secure. In your terminal, execute the script:

python3 simple_robot.py

Your robot should now move forward and stop when it detects an object within 30 cm. Feel free to tweak the code to adjust speeds, incorporate different movements, or add new sensors for more functionality.

Conclusion

Congrats on building your own basic robot with Raspberry Pi! This project introduces you to the basic principles of robotics and microcontroller programming. With Raspberry Pi, the sky’s the limit, so keep experimenting with new components and ideas.