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.

At the heart of the Zumo 32U4 is an Atmel ATmega32U4 AVR microcontroller, and like our A-Star 32U4 programmable controllers, the Zumo 32U4 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.

Assembled Zumo 32U4 robot, front view.

Assembled Zumo 32U4 robot, side view.

Assembled Zumo 32U4 robot, back view.

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.

The Zumo 32U4 robot is available fully assembled with three different motor options (see the Motors section below for more information on how these different gear ratios perform):

Assembled with 50:1 HP motors — highest speed and lowest torque of the three options
Assembled with 75:1 HP motors — average speed and torque
Assembled with 100:1 HP motors — highest torque and lowest speed

This version of the Zumo 32U4 robot (item #3126) ships fully assembled with a pair of micro metal gearmotors (with extended motor shafts). As described above, two other assembled versions are also available, one with a higher gear ratio that is slower but can deliver more torque and one with a lower gear ratio that is faster but delivers less torque.

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.

Micro Metal Gearmotor	Free-Run Speed @ 6V	Stall Torque @ 6V	Stall Current @ 6V	Top Zumo Speed @ 6V and 500g
50:1 HP or 50:1 HPCB	625 RPM	15 oz·in	1600 mA	40 in/s	(100 cm/s)
75:1 HP or 75:1 HPCB	400 RPM	22 oz·in	1600 mA	25 in/s	(65 cm/s)
100:1 HP or 100:1 HPCB	320 RPM	30 oz·in	1600 mA	20 in/s	(50 cm/s)

Batteries (not included)

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.

Optional accessories

Even more sensors
Connectors (headers, jumper wires, etc) for adding those sensors or other peripherals
Tools (soldering iron, diagonal cutters, pliers, screwdrivers, etc) to help with kit assembly

Comparison with the Zumo robot kit for Arduino (with Zumo Shield)

Our older Zumo robot for Arduino, built with a Zumo Shield, is another Arduino-compatible robotic platform based on the Zumo chassis. The Zumo Shield mounts to the Zumo chassis and features motor drivers and various sensors, but it does not have an integrated microcontroller; rather, it is designed to interface with boards that have a standard Arduino form factor, like an Arduino Uno, Arduino Leonardo, or A-Star 32U4 Prime, and these boards serve as the main controller for the robot.

A Zumo 32U4 robot (left) and a Zumo robot for Arduino with an A-Star 32U4 Prime LV (right).

By contrast, the Zumo 32U4 includes an on-board ATmega32U4 microcontroller (the same one used in the Leonardo and A-Star 32U4 boards), combining the functions of the Zumo Shield and the separate Arduino controller into a single, compact board that is just as easy to program as a standard Arduino or A-Star thanks to its USB interface and preloaded Arduino-compatible bootloader. The Zumo 32U4 retains all the features of the Zumo shield (e.g. dual motor drivers, inertial sensors, and buzzer) while adding many new features, including dual quadrature encoders, proximity sensors, an LCD, and two extra user pushbuttons.

Some of the pin mappings and software libraries differ between the Zumo 32U4 and Zumo robot for Arduino, so programs written for one robot generally need to be modified to work on the other.