April 1998, by Jim Brown
August 2002, page format revised, links update by NCC
July 2004, additional graphics provided by Bob Jordan

Project Summary

The goal of this project is to create a carrier board for an L298 H-Bridge with 1000mf cap, 12 diodes, a terminal block for power and two motors, and a header for interfacing with a microcontroller. The board is based on a simple L298 H-Bridge design by Clay Timmons.Continue reading

LegoBot: HC11 Controlled Autonomous Robot

by David P. Anderson
2 August 2002


The LegoBot is constructed from my sons’ Lego Technics set and has used several different micro-controllers. In the present incarnation its brain is a a Motorola HC11 running in an M.I.T. 6.270 board. This is the same type of controller we’re using on SR04 and Nbot, without the extra expansion board.

For a Lego enthusiast this is not a pure Lego design, as we have incorporated an aircraft plywood spine to strengthen the battery supports, and judicious application of plastic cable ties at various points in the chassis. The inclusion of these structural members has provided a robust platform that has remained rigid and functional for more than three years of use and abuse.Continue reading

Bill and Ron’s Robot Adventure

by Bill Boyers and Ron Brandenburg
21 April 2001

Take two self-employed bikers — one into computers and electronics, the other a machinist, add a machine shop, a Basic Stamp and a trip to Wal-Mart, and this is what you get.

In The Beginning . . .

We originally had no clue as to where we were headed. Rick was working on a robot and asked me to machine some hubs for his wheels. When I was done, I said “what the heck, I’ll build a robot too…” It was downhill from there.

We had a vague idea of where we were headed, so I ordered the motors and battery from Jameco, and paid a visit to Wally World for some scooter wheels. A visit to the local scrap yard yielded a big 0.190″ thick aluminum plate for the chassis.Continue reading

SR04 Mobile Robot

by David P. Anderson
8 March 1998



SR04 is a small mobile robot suitable for exploring human habitats unattended. It is controlled by a Motorola HC6811 microprocessor running in an M.I.T. 6.270 CPU card, similar to the commercially available “Handy Board.” Two 12-volt DC gear-head motors maneuver the robot in a dual-differential drive configuration, balanced by a non-driven tail wheel caster and powered by a 12 volt 2.2 amp-hour sealed lead acid battery. Sensory input is provided by (in order of priority): front bumper switches, IR collision avoidance, stereo sonar ranging, photo detectors, passive IR motion detection, and shaft-encoder odometry.Continue reading