Build a Bluetooth RC car

Build a two-wheel robot car you drive from an Android phone over Bluetooth, with a safety stop that halts it when the phone goes quiet.

Time1–2 weekends

Parts₹1,650–1,750

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

Before you start

Tools: Laptop with the Arduino IDE, An Android phone (an HC-05 can't connect to an iPhone), Screwdriver, Soldering iron, only if your motors come without wires
Skills: A first robot with wireless control. Basic wiring and a three-resistor divider on a breadboard; steps 2–5 use code (or Get the code). Built the line follower? Steps 1–2 are the same chassis and motor wiring.
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. Test new code with the wheels off the table: a car that won't stop is the main risk here, which is why the code stops it when the phone goes quiet.
Prices: Checked 2026-10, with a clone Uno, protected cells, a Li-ion charger and a small breadboard; an original Uno adds about ₹1,950

Step 1 of 5

Chassis built

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

Task 01 of 07

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
Small solderless breadboard (400 points)
Screwdriver, M3 screws and spacers, double-sided tape