The Pololu Zumo 32U4 robot is a versatile tracked robot based on the Arduino-compatible ATmega32U4 MCU, and this kit contains most of the parts you need to build one—all you need to add are a pair of micro metal gearmotors and four AA batteries. It includes integrated dual motor drivers, an LCD, quadrature encoders, line sensors, side and front proximity sensors, and a full IMU. The assembled robot is less than 10 cm × 10 cm—small enough to qualify for Mini Sumo. This product is a kit; assembly (including soldering) is required.
This robot required the extended shaft Micro Metal Gear Motors to make use of the encoders.