3pi+ 32U4 OLED Robot - Standard Edition (30:1 MP Motors), Assembled

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Pololu item #: 4975
Brand: Pololu
Status: Active and Preferred 
RoHS 3 compliant


The Pololu 3pi+ 32U4 OLED robot is a complete, high-performance mobile platform based on the Arduino-compatible ATmega32U4 MCU. Its many features include dual quadrature encoders for closed-loop speed or position control, line sensors, front bump sensors, a full IMU (3-axis accelerometer, magnetometer, and gyro), and a graphical OLED display, all packed into a robot that fits in the palm of your hand. This Standard Edition version is assembled with 30:1 MP 6V Micro Metal Gearmotors, which offer a good combination of speed and controllability.

Alternatives available with variations in these parameter(s): version assembled Select variant…

Pictures

3pi+ 32U4 OLED Robot.

3pi+ 32U4 OLED Robot, rear view.

3pi+ 32U4 OLED Robot fits in the palm of a hand.

3pi+ 32U4 OLED Robot features.

3pi+ 32U4 OLED Robot, front view.

3pi+ 32U4 OLED Robot, side view.

3pi+ 32U4 OLED Robot, rear view.

3pi+ 32U4 OLED Robot, top view.

3pi+ 32U4 OLED Robot, top view with OLED display removed.

3pi+ 32U4 OLED Robot, bottom view.

The 3pi+ 32U4 OLED Robot is powered by four AAA batteries (not included).

3pi+ 32U4 OLED Robot, bottom view with battery compartment covers removed.

3pi+ 32U4 OLED Robot, bottom view.

3pi+ 32U4 OLED Robot, bottom view with batteries installed (batteries not included).

3pi+ 32U4 OLED Robot, bottom view showing the insides of the battery compartments.




Overview

The 3pi+ 32U4 OLED is a versatile, high-performance, user-programmable robot that measures just 9.7 cm (3.8″) in diameter. At its heart is an ATmega32U4 AVR microcontroller from Microchip (formerly Atmel), and like our A-Star 32U4 programmable controllers, the 3pi+ 32U4 features a USB interface and ships preloaded with an Arduino-compatible bootloader, so all you need to program it is a USB A to Micro-B cable (not included). 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. For advanced users who want to customize or enhance their robots with additional peripherals, the robot’s power rails, power system controls, and microcontroller’s I/O lines can be accessed via several 0.1″-pitch expansion ports.

3pi+ 32U4 OLED Robot, front view.

3pi+ 32U4 OLED Robot, side view.

3pi+ 32U4 OLED Robot, rear view.

The 3pi+ (or 3𝜋+) 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 left and right bump sensors along the front face of the robot. Three on-board pushbuttons offer a convenient interface for user input, and a 128×64 graphical OLED display, buzzer, and indicator LEDs allow the robot to provide feedback.


The robot also features a unique power system that runs the motors at a constant 8 V independent of the battery charge level, so the speed of the motors does not vary with the battery voltage.

The 3pi+ 32U4 OLED robot is available as a kit or fully assembled with three different motor options:

3pi+ 32U4 OLED Version Products Micro Metal Gearmotor Top Speed Comments
Standard Edition assembled or kit 30:1 MP 6V 1.5 m/s good combination of speed and controllability
Turtle Edition assembled or kit 75:1 LP 6V 0.4 m/s longest battery life, easiest to control, good for swarm robots or introductory robotics courses
Hyper Edition assembled or kit 15:1 HPCB 6V ~4 m/s very fast and difficult to control, easy to damage; only recommended for advanced users

For those who would prefer to use different motors than these versions above, the 3pi+ chassis and 3pi+ 32U4 OLED control board are available separately and can be combined with a pair of motors to make a custom kit.

March 2024 update: We are transitioning the OLED displays from units with blue PCBs to functionally identical versions with black PCBs. Some of the pictures and videos on our website still show the original blue displays.

What else you will need

Assembling the kit version

Details for item #4975

This product is the assembled Standard Edition of the 3pi+ 32U4 Robot.

This is a newer 3pi+ 32U4 OLED Robot with a graphical OLED display. For its original version counterpart with an LCD, see the 3pi+ 32U4 Robot – Standard Edition (30:1 MP Motors), Assembled.

3pi+ 32U4 versions

The original version of the 3pi+ 32U4 includes an 8×2 character LCD, while this newer 3pi+ 32U4 OLED incorporates a graphical OLED display instead. The name “3pi+ 32U4” can generally be used to refer to both the original (LCD) and OLED versions, and the documentation in our updated user’s guide covers both versions.

Our Arduino library for the 3pi+ 32U4 generally allows code written for the LCD version to work on the OLED version with minimal changes (and the reverse is also true as long as your code does not make use of the OLED’s graphical capabilities).

3pi+ 32U4 Robot, top view.

3pi+ 32U4 OLED Robot, top view.

Comparison with the original 3pi

Original Pololu 3pi robot.

The 3pi+ 32U4 OLED offers many major improvements over the original 3pi, including:

The 3pi+ 32U4 uses a different microcontroller with different pin mappings compared to the older 3pi, and some of the software library interfaces are different, so programs written for the original 3pi will not work on the 3pi+ 32U4 without modification.

Dimensions

Size: 97L × 96W × 36H mm
Weight: 100 g1

General specifications

Processor: ATmega32U4 @ 16 MHz
RAM size: 2560 bytes
Program memory size: 32 Kbytes2
External programmer required?: N
Assembled: Y
Version: Standard Edition (30:1 MP Motors)

Identifying markings

PCB dev codes: 3pi03b
Other PCB markings: 0J13485

Notes:

1
Of assembled robot without batteries.
2
Note that 4 KB of the MCU's 32 KB of flash memory is used by the pre-installed USB bootloader. All 32 KB is available when programming via the ISP header rather than the bootloader.

Documentation and other information

File downloads

Recommended links

Frequently-asked questions

No FAQs available.

On the blog