What it is
A remote-controlled car built on top of an Arduino Uno. It takes input from a 2.4 GHz receiver, mixes the channels, and drives two motors through an H-bridge. Steering is differential — faster on one side than the other. Not elegant, but it works and it's mine.
Why I built it
I'd done smaller experiments — blinking LEDs, reading sensors, that sort of thing — and I wanted a project that would actually move. Something physical. Something with enough moving parts to force me to understand how they connect. An RC car was the smallest complete system I could think of that still felt like a real machine.
What's inside
- Arduino Uno as the brain, reading the RX channels on digital pins.
- nRF24L01 module handling the 2.4 GHz link to a matching transmitter.
- L298N H-bridge for direction + PWM speed control on both motors.
- LiPo 2S battery through a buck converter for the logic rail.
- A chassis I built, broke, and rebuilt twice.
What I learned
PWM noise is real. The first prototype had the motors coupled to the logic rail through a shared ground, and the receiver would glitch every time the motors spiked. Separating the power domains fixed it — obvious in hindsight, not obvious when it was 2am and the car was driving itself into walls.
I also learned that "just add a capacitor" is the oldest cliché in electronics for a reason. A 100μF across the motor leads quieted things down enormously.
What I'd do differently
Go to a proper motor driver next time — the L298N is fine for learning, but it's lossy and it gets warm. A MOSFET-based driver would be cleaner and let the battery last longer. Also: design the chassis before ordering parts, not after. Ask me how I know.