I started this robot-project as a preparation to the Melixis safety trophey. But when Melixis changed the rules significant, this goal was abandoned (which turned out to be a good deciscion - there has never been a Melixis match with the new rules). For the second open RobotMC club championship, I substitued the hitachi microcontroller by an Arm processor, added a wide frame and some sensors. This enabled the robot to compete in "blikken" and win the first place :-)
Mechanics
M-Bot is a robot with a differential drive. It's frame is made of aluminium. The wheels are mounted on 6mm bolts, which fit in two ball-bearings in the frame. The wheels are driven via gears (20T and 30T) by two gearhead motors. The top speed with the current gear ratio is 55 cm/s, but by swapping the two gears, it can be upgraded to 82 cm/s.Sensors
- two Hamamatsu P5587 IR Photoreflector to track motor speed
- two Devantech SRF08 High Performance Ultrasonic Range Finder
- five Sharp Distance measuring sensors
- One sharp IS471F Proximity Detector
Microcontroller
The main controller of M-Bot is an ARM processor from EmbeddedArtists.com- The console, with an lcd display, a numeric keyboard, Lego remote control receiver. This board also hosts the ARM processor board.
The motorcontroller - a PICMicro 16F876 which controls two discrete H-bridges for the motors. The base controller (PICMicro 16F877) which measures the speed of the motors and reads - Two Devantech Ultrasonic range finders
Software
The PICMicro controller is programmed in C. The slave controllers are programmed in JAL. 
botom view – On the bottom the 16F876 controller with the two h-bridges and power connectors is shown. In the middle, the two motors and external gears are visible. The frame has to be extended to give room for a proper battery compartiment at the top...
odometer – A small wire is soldered on the asix of the motor and a black-and-white paper is glued to this wire. The P5587 is soldered on the sides of two small PCBs and positioned with an m3*20 bolt and a few nuts.
Links:
My Robots