Pololu Zumo 32U4 Robot Kit (No Motors) [discontinued]

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.

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This version of the Zumo 32U4 robot is a kit; assembly (including soldering) is required. Motors and batteries are sold separately. A USB A to Micro-B cable (not included) is required for programming.

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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 ATmega32U4 AVR microcontroller from Microchip (formerly Atmel), 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.

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.

Kit Contents

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 (this includes two magnetic encoder discs that work with encoder sensors integrated into the main board and a through-hole buzzer)
• Zumo 32U4 Front Sensor Array
• Stainless steel Zumo 32U4 Blade and plastic IR LED holder
• 8×2 character LCD

See the Zumo 32U4 robot user’s guide for detailed assembly instructions.

Resources

• User guide
• Pinout diagram
• Schematic
• 3D Model (Assembled)
• 3D Model
• Dimension Diagram (mainboard)
• Drill guide (mainboard)
• Datasheet for the Sharp GP2S60 compact reflective photointerrupter
• Vishay TSSP77038 IR receiver module datasheet
• Zumo 32U4 Arduino library
• Zumo32U4 library documentation
• ATmega32U4 documentation
• Using the L3GD20 gyroscope in control systems
• Texas Instruments DRV8837/DRV8838 motor driver datasheet
• TPS2113A datasheet

Motor Recommendations (not included)

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 (motors are included with the assembled versions of the Zumo 32U4 robot). 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.

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

Battery Recommendations (not included)

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

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.

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.