This was a team project for the class Mechatronics & Gadgetry at CMU. 

 

The goal was to build an autonomous mobile robot from scratch on a $150 budget which was capable of navigating a walled maze. For controls and comms, our team used an Arduino Mega for controls and onboard computing and an ESP32 Wi-Fi module connected through serial for wireless logging. Odometry/Actuation was done using quadrature encoders mounted to each of the 2 DC motors with the robot's rear supported by a ball bearing. Distance to walls was measured using 3 HC-304 ultrasonic sensors, giving us depth measurements on the front and spacing/corner detection on the sides using differential sensing. Distance and controlled turn radius are indicated using the 12-LED ring placed on the rear. The red "Stop" wall is detected using a color sensor mounted to the rear side. Due to the high power requirements of a Wi-Fi antenna, LEDs, and DC motors, a 12V LiPo battery and motor shield/step down converter are used to power all systems.  We used a simple 3d printed chassis to house all the electrical components, and 3D printed TPU treads to increase the robot's mobility and precision with dead reckoning.