Build a line-following robot

Build a two-wheel robot that sees a black line with infrared sensors and steers itself along it.

Time2–3 weekends

Parts₹1,630–1,990

Free. Make an account and you come straight back to start it.

Before you start

Tools: Laptop with the Arduino IDE, Screwdriver, Multimeter (continuity/beep mode), Li-ion charger, Soldering iron, only if your motors come without wires, Black electrical tape and white chart paper
Skills: A first robot. Basic wiring; steps 2–5 use code (or Get the code).
Safety: Li-ion cells: protected cells and a proper charger only, and never short them. Protected bare 18650s can be hard to find in Indian shops, so check they fit your holder before you buy.
Prices: Checked 2026-10, with a clone Uno and protected cells; an original Uno adds about ₹1,950; the upper end includes a half-size breadboard (up to ₹200, Arya's estimate 2026-10-17)

Step 1 of 5

Chassis built

Motors, wheels, caster and battery holder are fixed to the chassis, and it rolls freely.

Task 01 of 08

Lay out every part from the kit and match it to the parts list. Keep the small screws in a cup.

Check: Nothing is missing before you start.

You need

2WD acrylic chassis kit (2 BO motors rated 3–6 V, 2 wheels, caster)
Arduino Uno R3
L298N motor driver module
2 × 18650 holder with an on/off switch
2 × protected 18650 Li-ion cells (check they fit your holder: protected cells are a few mm longer) and a Li-ion charger
Screwdriver, M3 screws and spacers, double-sided tape