Object Following Robot with Arduino
π Overview
A car that locks onto a target: the camera spots an object of a specific colour (a red ball, say), works out where it is in the frame, and the Arduino drives the left and right motors so the car keeps facing and following it.
This is a vision plus motion-control project across software and hardware: Python handles recognition and decisions and sends commands to the Arduino over serial - a starter prototype for smart following or patrol robots.
π§° What you need
- Arduino board (Uno/Nano) + L298N motor driver
- Two-motor robot chassis + wheels + battery
- Camera (USB to a computer, or a Raspberry Pi)
- A coloured target object (a red or green ball, for example)
- Python 3 + OpenCV + pyserial
π§ Step by step
Assemble the hardware
Wire up the chassis, motors, and driver board
Write an Arduino sketch to test forward, backward, and turning first
Colour detection
Filter the target colour in the HSV colour space
Use morphological opening and closing to clean the mask and take the largest contour as the target
Locate the target
Measure the offset between the contour centre and the frame centre
The horizontal offset decides steering; the target size decides forward or backward
Serial communication
pyserial on the Python side sends commands to the Arduino
Define a simple protocol: direction plus speed (for example 'F 100')
Arduino execution
Parse the serial commands and drive the motors
Add a timeout: stop automatically when no command arrives
Tune the following behaviour
Go forward only when the target is centred; turn left or right when it is off-centre
Back away when the target gets too close (too large) to hold distance
Integration and wrap-up
Test the colour thresholds under different lighting
Adjust the camera angle and the car's speed
π‘ Tips
- Calibrate HSV thresholds with a colour picker; filtering in raw RGB is very sensitive to lighting
- Add a newline and exception handling to the serial protocol to avoid partial reads
- Tie the motor PWM speed to the steering angle (slow down while turning) for smoother motion