The Pololu 3pi robot is a complete, high-performance mobile platform featuring two micro metal gearmotors, five reflectance sensors, an 8×2 character LCD, a buzzer, and three user pushbuttons, all connected to a C-programmable ATmega168 microcontroller. Capable of speeds exceeding 3 feet per second, 3pi is a great first robot for ambitious beginners and a perfect second robot for those looking to move up from non-programmable or slower beginner robots. For instructions on setting up and programming the 3pi, including sample code, contest ideas, and more, see the 3pi User’s Guide.
Our starter kit comes with an Orangutan USB AVR Programmer and USB Cable, which is everything needed to get started programming this versatile and advanced little robot.
The 3pi robot is designed to excel in line-following and maze-solving competitions. It has a small size (9.5 cm/3.7" diameter, 83 g/2.9 oz without batteries) and takes just four AAA cells (not included), while a unique power system runs the motors at a constant 9.25 V independent of the battery charge level. The regulated voltage allows the 3pi to reach speeds up to 100 cm/second while making precise turns and spins that don’t vary with the battery voltage.
The 3pi robot makes a great platform for people with C programming experience to learn robotics, and it is a fun environment for ambitious beginners to learn C programming. At its heart is an Atmel ATmega168 microcontroller running at 20 MHz with 16KB of flash program memory and 1KB data memory, enough space to run complicated programs. An extra 512 bytes of persistent flash memory is provided on the microcontroller for data logging or long-term learning applications. The popular, free GNU C/C++ compiler works perfectly with the 3pi, Atmel’s AVR Studio provides a comfortable development environment, and an extensive set of libraries provided by Pololu makes it a breeze to interface with all of the integrated hardware. The 3pi is also compatible with the popular Arduino development platform. We provide a number of sample programs to show how to use the various 3pi components, as well as how to perform more complex behaviors such as line following and maze solving.
The diagrams below highlight the important features of the 3pi. Click on either picture for an expanded view.
Looking to expand your 3pi Robot? Check out the 3pi Expansion Kit!
3pi expansion kit with cutouts mounted on a 3pi robot.
- Size: 3.7" diameter
- Processor: Tmega168
- Motor driver: TB6612FNG
- Motor channels: 2
- User I/O lines: 21
- Minimum operating voltage: 3v
- Maximum operating voltage: 7v
- Maximum PWM frequency: 80 kHz
- Reverse voltage protection?: Yes
- External programmer required?: Yes
- Digital I/O lines PD0 and PD1 are available; two more analog inputs and one analog/digital pin can be made available by removing jumpers and disabling special features of tde board.
- Designed for use with 4 x AAA NiMH or Alkaline cells. A step-up regulator boosts the motor voltage to 9.25 V.
- A free, open-source suite of development tools for the AVR family of microcontrollers, including the GNU GCC compiler for C/C++.
- AVR Studio
- Atmel’s free AVR integrated development environment (IDE) that works with WinAVR’s free GCC C/C++ compiler.
- ATmega168 documentation
- Atmel’s product page for the ATmega168.
- Pololu Robotics Forum
- Pololu Robotics and Electronics forum—get technical support, share your project, or just drop in to say hi.
- Pololu 3pi Forum Section
- The 3pi discussion section of the Pololu Robotics Forum.
- AVR Freaks
- AVR community with forums, projects, and AVR news.
- Tutorial: AVR Programming on the Mac
- Customer Michael Shimniok has written a guide to programming AVRs (the Orangutan LV-168, specifically) using the Mac.