It's small, fast, and very well designed line-following/maze solving robot. And a great deal!
When we first saw pictures of the 3pi robot, we thought "Ah, another minibot...sigh...".
Then we saw the video!
This robot is definitely raises the bar for the competition in the preassembled robot marketplace! It's FAST. It's WELL DESIGNED. And most importantly, it's a great value.
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). What's really cool is that Pololu has incorporated a well-designed power system that runs the motors at a constant 9.25V, no matter what condition the batteries are (up to the point where the batteries are dead!). This regulated voltage for the motors makes them run very consistently, letting the 3pi robot zoom up to 100 cm/second (3.3' per second!) and maintain the ability to make precise turns.
The brains of the 3pi robot is the very popular Atmel ATmega328, which is compatible with the open-source Arduino / Freeduino SB project. Because of this, you can program your 3pi using the open-source GNU C language, or even use the open-source Arduino development system. Both are very powerful, very popular, and free!
You'll need a hardware programmer of some sort to connect your 3pi robot to your computer. Any AVR programmer compatible with AVRDude or AVRISP will work. We suggest any of the following:
Atmel's own STK500, AVR-ISP, or Dragon ISP programmers
In short, it's a kick-butt line-following, little robot, well worth your investigation! (Check out this video!)