Bill's Bot
Mini Sumo Robot




Body of the robot without the front scoop.
9 volt battery not mounted yet



Front scoop attached



Two GM8 motors to drive the robot.
Donated by Solarbotics at the summer RSA robot games. 
Thank you Solarbotics!



Batteries mounted on the bottom. 9V battery to be mounted on top



9 volt battery holder mounted on top, toward the front.

Power ON/OFF switch and PICKEY program port added.

A strip of phenolic plastic was made into a line sensor. The unit is placed inside the front scoop of the robot and later painted flat black on the surfaces. Side light shields were later added.

Green LEDs illuminate the table top. Reflected light is detected by CDS photoconductive resistors. 
The CDS cells have a peak spectral sensitivity of 515 nanometers, near the color green.

Line sensor from the back. Ribbon wire connects the LEDs and CDS cells



Top View

Microcontroller is a PIC 16F876 20/SP from Microchip



Side View



IR (EMF shielded) sensors mounted behind the front scoop



Front View of IR LED mounted in the center.

IR object sensors to the right and left.



View showing black felt attached for stealthiness.
The felt prevents the opponent's IR from finding the robot.



Robot with special dual battery charger to the right.



Add the extra wide scoops and it becomes "billsbot2" an entry for the 3kg Autonomous Sumo class.



All by myself and no one to play with!

Program highlights and features:

1. Ability to calibrate for black surface and white line and save values in Data Rom.
2. Button to activate a five second countdown.
3. Makes sounds as it moves.
4. Debug output to PC for testing.
5. Red and Green test LEDs.
6. Uses EMF sheilded IRleds at 56kc to detect opponent.
7. Antirefective surfaces for stealth.
8. Recharge jack for both battery systems with total external power for the pic if needed.
9. Program PIC using the PIC-KEY programmer.
10. PIC has 8k of program space plus spare ADC's, I/O and DATA ROM.
11. Warns if a bad calibrate sequence is performed.
12. Regenerative braking with full H-bridge motor control.

Download the Pic Pro Basic program files here (updated 4-5-2004):
Program into a Microchip PIC 16F876 20/SP



You are free to use any of the circuits on my webpages for personal or educational use and not for commercial use.
These designs are experimental and may not fully work for you.  I will not be responsible for any damages to any computer, equipment, mental or bodily injury, or for lost revenue due to the use of these designs.


Schematic Drawing of PIC Controller (PDF) updated 2-21-04

Instructions on operating Billsbot (PDF)

You can E-mail me (Bill Sherman) at