Build a Line-Following Robot: From Idea to Working Bot

A line-following robot detects a dark line on a light surface (or vice versa) and steers to stay on track.

Hardware

• Microcontroller (Arduino/Nano)
• IR array sensors (3–5)
• 2x DC gear motors, wheels, caster
• Motor driver, battery pack

Software

// Pseudocode
read_sensors();
error = target - measured_line_position;
output = Kp*error + Ki*sum(error) + Kd*d(error)/dt;
set_motor_speeds(base + output, base - output);

Tune PID gains gradually. Start with Kp, then add Kd to reduce overshoot, and finally Ki to remove steady-state error.