S ScienceFairProjects.info
Hard⏱ time3 hr$ cost28

Obstacle-Avoiding Robot

An Arduino car reads distance with ultrasonic sound and steers itself away from walls.

Start building ↓
fig — working model Result first

The build

Step 01

Build the chassis

Mount motors, wheels and the Arduino on the frame.

Step 02

Wire the driver

Connect motors to the L298N and control pins to the Arduino.

Step 03

Mount the sensor

Fix the ultrasonic sensor facing forward.

Step 04

Flash & roll

Upload code: drive forward, and turn when something is too close.

Working Principle

The robot runs a sense–decide–act loop: it pings distance, and when an obstacle is within a set range it stops and turns toward open space.

The science behind it

A closer look

The HC-SR04 times an echo to measure distance (distance = speed of sound × time ÷ 2); the code closes a simple feedback loop.

Take it further

Variables to test

  • 1 Lower the turn threshold — braver or crashier?
  • 2 Add a second sensor — smoother navigation?

More Robotics