Kindly Morrow
Arduino 4WD Robot Car Kit Bluetooth Tracking Obstacle Avoid
Build a four-wheel-drive robot that follows lines, dodges obstacles, and takes commands from your phone. All the sensors are onboard and talk to each other. You write the logic.
The L298N motor driver gives you independent PWM control over each wheel pair, so differential steering is straightforward to implement in code. Four IR sensors handle line tracking and edge detection simultaneously, while the HC-SR04 measures distances up to 4 meters via timed ultrasonic pulses. The HC-06 Bluetooth module shows up as a serial port on your phone, which makes it easy to send commands or stream sensor data during testing. Needs an Arduino Uno (not included).
Things to build with this
- Use the four IR sensors in a differential array to program a PID line-following algorithm, tuning proportional and derivative constants to keep the car centered on a tape track at varying speeds
- Combine the HC-SR04 echo timing with the L298N PWM output to program a wall-following mode where the car maintains a fixed distance from a surface by adjusting motor speed in a feedback loop
- Send structured command packets over the HC-06 serial link from a Python script on your laptop to log real-time IR and ultrasonic sensor values to a CSV, then replay the data to simulate and tune autonomous behavior without running the motors
Key Features
- L298N dual H-bridge motor driver: independent PWM speed and direction control for each wheel pair
- HC-SR04 ultrasonic sensor: obstacle detection from 2cm to 400cm using echo timing
- 4x IR sensors: configurable for line tracking, edge detection, or ground contrast reading
- HC-06 Bluetooth module: serial UART bridge at 9600 baud, pairs with any Android Bluetooth terminal app
- 4WD chassis: all four wheels driven, better traction than 2WD for uneven surfaces
- Arduino IDE compatible: standard libraries (NewPing, AFMotor, SoftwareSerial) all work out of the box
- Complete hardware kit: motors, sensors, wiring, and chassis included. Arduino Uno sold separately
Frequently Asked Questions
What do I need to buy separately to get this running?
An Arduino Uno and four AA batteries (or a 9V battery pack for the motors). Everything else, chassis, motors, sensors, wiring, motor driver, is in the kit.
Can all three modes (line following, obstacle avoidance, Bluetooth control) run at the same time?
Yes, but you have to write the logic for how they interact. A common pattern is to check the ultrasonic sensor first, override the line-following output if something is detected, and still accept Bluetooth commands to switch modes entirely.
What Bluetooth app works with the HC-06?
Any Android app that supports Bluetooth SPP (Serial Port Profile) works. Arduino Bluetooth Controller and Bluetooth Terminal are common free options. The HC-06 does not support iOS due to Apple's BLE-only restriction.
Is this suitable for someone who has never programmed before?
It works best if you have at least seen some Arduino code. The kit does not include step-by-step tutorials, but example sketches for each sensor are widely available and the libraries are well-documented. Expect to spend a few evenings wiring, uploading, and debugging.
Why we stock this
Curated by Kindly Morrow. We test and vet every product before it hits the store. If we wouldn't use it in our own builds, we don't sell it.
Things to build with this
Fun projects to try once you get your hands on it.
AI-controlled robot arm that sorts your desk
Connect it to Claude, point a camera at your desk, and let it pick up pens and put them back in the holder. Gloriously unnecessary.
Line-following robot for your hallway
Tape a black line from your office to the kitchen. The robot follows it carrying your coffee mug. Will your cat attack it? Probably.
Gesture-controlled car
Strap an accelerometer to your hand and steer the robot car by tilting. Makes you feel like a Jedi. Kids will never give it back.
Security patrol bot
Program a route through your house. Add a camera. Stream to your phone. Your dog will be confused, but your house will be watched.
