Pololu 3pi Robot

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 or ATmega328 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.

Overview:

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 or ATmega328P microcontroller running at 20 MHz. ATmega168-based 3pi robots feature 16 KB of flash program memory and 1 KB RAM, and 512 bytes of persistent EEPROM memory; ATmega328-based 3pi robots feature 32 KB of flash program memory, 2 KB RAM, and 1 KB of persistent EEPROM memory. 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.

Dimensions:

Size: 3.7" diameter
General specifications:
Processor: ATmega168/328P
Motor driver: TB6612FNG
Motor channels: 2
User I/O lines: 21
Minimum operating voltage: 3 V2
Maximum operating voltage: 7 V2
Maximum PWM frequency: 80 kHz
Reverse voltage protection?: Y
External programmer required?: Y

Notes:

· 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 the board.
· Designed for use with 4 x AAA NiMH or Alkaline cells. A step-up regulator boosts the motor voltage to 9.25 V.

Required Accessories:

An external AVR ISP programmer, such as our USB AVR programmer is required to program the 3pi. We offer a combination deal that includes a 3pi robot, USB AVR programmer, and USB cable.
The 3pi is powered by 4 AAA batteries, which are not included. We recommend rechargeable NiMH cells, which may be purchased from Pololu or at a local store carrying electronics.

A Video Introduction to the 3pi:

To see for yourself what the 3pi is like, please take a look at the video below, which introduces its basic features and operation.


More Pictures and Videos of the 3pi Robot:

The following video shows a 3pi prototype autonomously solving a line maze. It first runs through the maze executing a search algorithm, keeping track of which way it is turning at intersections and discarding paths that lead to dead ends. Once it finds the end, which is marked by a solid black circle, it determines from memory the best path from start to finish and on subsequent runs aggressively drives that shortest path. This is just one example of what the 3pi is capable of.


This unedited video shows six 3pi prototypes simultaneously participating in a line-following exhibition at a local robotics competition. The robots were all programmed independently. Last one remaining on the line wins!