3pi+ 32U4 Robot - Turtle Edition (75:1 LP Motors), Assembled
The Pololu 3pi+ 32U4 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, and a full IMU (3-axis accelerometer, magnetometer, and gyro), all packed into a robot that fits in the palm of your hand. This Turtle Edition version is assembled with 75:1 LP 6V Micro Metal Gearmotors, which allow for longer battery life than the other editions. The maximum robot speed is approximately 0.4 m/s, making it well suited for applications where slow, controlled speed is important, such as coordinated swarm robots and introductory robotics courses.
Alternatives available with variations in these parameter(s): version assembled
|Description||Specs (4)||Pictures (15)||Resources (12)||FAQs (0)||On the blog (2)|
New version available! We have released an updated 3pi+ 32U4 OLED Robot that includes an OLED display with better graphical capabilities than the LCD used by this original 3pi+ 32U4 robot. The OLED version is available with the same three motor options:
- Standard Edition (assembled or kit)
- Turtle Edition (assembled or kit)
- Hyper Edition (assembled or kit)
We recommend the newer 3pi+ 32U4 OLED over this original version, which will only be available by special order once our existing stock runs out.
The 3pi+ 32U4 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.
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 an LCD, 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 robot is available as a kit or fully assembled with three different motor options:
|3pi+ 32U4 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 control board are available separately and can be combined with a pair of motors to make a custom kit.
What else you will need
- four AAA batteries: the 3pi+ robot works with both alkaline and NiMH batteries, though we recommend rechargeable NiMH cells
- a USB A to Micro-B cable to connect the robot to your computer for programming and debugging
Assembling the kit version
Details for item #3738
This an original 3pi+ 32U4 Robot with an LCD. We recommend the newer 3pi+ 32U4 OLED instead, which includes a graphical OLED display; the updated version of this item is the 3pi+ 32U4 OLED Robot – Turtle Edition (75:1 LP Motors), Assembled.
This product is the assembled Turtle Edition of the 3pi+ 32U4 Robot.
3pi+ 32U4 versions
This original version of the 3pi+ 32U4 includes an 8×2 character LCD, while the 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).
Comparison with the original 3pi
Original Pololu 3pi robot.
The 3pi+ 32U4 offers many major improvements over the original 3pi, including:
- ATmega32U4 microcontroller with Arduino-compatible bootloader can be programmed directly through a USB connection
- Quadrature encoders on both motors for closed-loop position and speed control
- Full 9-axis IMU (three-axis gyro, accelerometer, and compass)
- Bottom-loading battery holders keep batteries accessible even if additional levels are added
- Full wrap-around bumper to protect electronics from collisions
- Two bump sensors on the front
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.