Mini Sumo Bot - “Pot Pi”

This is my first attempt to build a robot. I designed it to participate in the Mini Sumo (500g) division competitions.

For this project, I designed a custom PCB using the ExpressPCB Mini Board service. I used their software – below you can download my Schematic and PCB files. $51 for 3 boards, you can't beat that!

His first taste of action will be at the Chibotica/iHobby Expo competition on October 24-25, 2009. I hope to post some videos of the carnage.

Hardware involved:

For the brains on this board, I'm using a PIC 16F876A microprocessor. It's a great chip with 2 PWM outputs, and a number of analog inputs so it was perfect for this project.

I wrote the code in C, using the Hi-Tech PICC Lite compiler.

To power this guy, I'm using a 25C 11.1v 1500mAh LiPo battery pack. I ordered it from Go_Market on eBay. Yeah, it's probably overkill but didn't want to risk running out of juice in the middle of a match.

The chassis is simply a cheap aluminum project enclosure that I picked up from Radio Shack. After much hammering, bending, drilling and cursing, I ended up with a housing for all my components.

I'm using the Solarbotics GM9 motors and matching wheels.

To control the motors, I use the ST L298N Dual Full-Bridge Motor Driver. This is a great chip allowing for PWM control, delivering up to 2A per channel.

For sight, I gave my bot 3 Sharp GP2D12 IR Rangers. These devices return an analog signal back to the PIC based on the distance an object is away, with a range of 10-80cm.

Files:

Here is the source code for the PIC processor.

Here are the ExpressPCB Schematic and PCB files.

Some action shots: