The Zumo 32U4 is a highly integrated, user-programmable and customizable tracked robot. It measures less than 10 cm on each side and weighs approximately 275 g with batteries (170 g without), so it is both small enough and light enough to qualify for Mini-Sumo competitions, but its versatility makes it capable of much more than just robot sumo battles.
It includes integrated dual motor drivers, an LCD, quadrature encoders, line sensors, side and front proximity sensors, and a full IMU.

At the heart of the Zumo 32U4 is an Atmel ATmega32U4 AVR microcontroller, features a USB interface and ships preloaded with an Arduino-compatible bootloader. A software add-on is available that makes it easy to program the robot from the Arduino environment, and we have Arduino libraries and example sketches to help get you started. A USB A to Micro-B cable (not included) is required for programming. For advanced users who want to customize or enhance their robots with additional peripherals, the robot’s power rails and microcontroller’s I/O lines can be accessed via 0.1″-spaced through-holes along the sides and front of the main board.

The Zumo 32U4 features two H-bridge motor drivers and a variety of integrated sensors, including a pair of quadrature encoders for closed-loop motor control, a complete inertial measurement unit (3-axis accelerometer, gyro, and magnetometer), five downward-facing reflectance sensors for line-following or edge-detection, and front- and side-facing proximity sensors for obstacle detection and ranging. Three on-board pushbuttons offer a convenient interface for user input, and an LCD, buzzer, and indicator LEDs allow the robot to provide feedback.

With the exception of motors, batteries, and a USB A to Micro-B cable, this kit contains everything necessary to build and operate a Zumo 32U4 robot:

-Zumo chassis kit
-Zumo 32U4 main board
-Zumo 32U4 front sensor array
-stainless steel Zumo 32U4 blade
-8×2 character LCD
-two magnetic encoder discs (the encoder sensors are integrated into the main board)
-IR LEDs (proximity sensor emitters; the detectors are integrated into the front sensor array)
-through-hole buzzer
-assorted hardware and connectors

Motors

The Zumo chassis uses two micro metal gearmotors, one for each tread. The ideal motors for your robot depend on your desired torque, speed, and current draw, so motors are not included with the kit version of the chassis. We generally recommend using high-power (HP or HPCB, which have long-life carbon brushes) versions of our micro metal gearmotors since the tracks require a decent amount of torque to move effectively; higher gear ratios of the non-HP motors might work if you want lower current draw, but they will be slower and offer less control. Specifically, we primarily recommend the 50:1, 75:1, or 100:1 HP (or HPCB) motors for use with this chassis, and these are the versions we include in our assembled Zumo 32U4 robot. Additionally, be sure to get a version with extended motor shafts if you want to be able to use the Zumo 32U4’s encoders.

You can use the following table to compare these three gear ratios in more detail. The first four columns are specifications of the motors themselves, while the last column is the measured top speed of a Zumo chassis loaded to a weight of 500 g and driven with these motors. Note that the specifications are for 6V operation, which is approximately the voltage you would get with four alkaline batteries; four NiMH AA cells will typically provide less than 5V.

Batteries

The Zumo 32U4 robot runs off of four AA batteries. It works with both alkaline and NiMH batteries, though we recommend using rechargeable AA NiMH cells.

Other resources

On the Pololu product page (on bellow link):

https://www.pololu.com/product/3124

you will find more informations, pictures, resources and programming examples.