This is my vivarium where I create, nurture and house my creations. You are invited to browse and enjoy. But watch your fingers. No telling who might have evolved teeth overnight.

This page lists my most recent projects. For a complete list, check the Projects page. OK, they're actually the same for the moment but I hope that that will change with time.

Finally, a disclaimer: I want to warn you that I am not an electrical engineer or even an electronics technician. I am a chemist and a computer programmer. My designs might be stupid, violate guidelines, and be an affront to any self-respecting engineer. I'm a hobbyist and I do this for fun.

Fitzy - Robot Challenge (updated March 28, 2012)

Last year my son and I built some robots. They performed some simple behaviours and I considered the build a success. But the design did suffer from several flaws which I hope to remedy in this year's build. March Break has come and gone but development continues. I hope that this will be a platform for some longer term development.

DIY Fresnel Reflector

Fresnel reflectors consist of concentric mirrored rings. Each ring is tilted inward by a precise angle. Any light falling on the ring from above is reflected toward a central focal point. The angle of the tilt needs to be quite precise and this makes the construction of a Fresnel reflector a bit tricky. In this post I present a program that you can use to generate an easy cutting guide that will guarantee a working Fresnel reflector.

T-Pro SG90 Micro Servo - Autopsy

In the course of troubleshooting my PolyPod project I performed an autopsy on a T-Pro SG90 servo. I was looking for the source of a problem I was having but it turned out to be somewhere else entirely. During the autopsy I mapped out the PCB and discovered that the servo uses the AA51880 servo chip and virtually the reference design. Most interestingly, the PCB has untapped potential to drive larger motors using transistors or MOSFETs.

Building a Better Bipolar Stepper Motor Driver

I've been working on and toward this project for some time and have finally finished. Making physical things move under computer control gives me a special thrill. There's a special enjoyment to be had watching stepper motors spinning about. I've provided full schematics, gerber files and code.

Using a Light-Pipe as a Robotic Sensor

As I work on my polypod robot I'm considering options for sensors. I've always felt that a machine needs to be autonomous for it to really be a robot. That means it has to sense the world and make decisions based on what it detects. I've been trying to come up with an idea for force sensors on the feet so they can tell when they're touching something. I had an idea that a simple DIY light-pipe might work.

Building a Big Daddy Halloween costume - 2011

Last year we built a DALEK. My son won a prize and got his 15 seconds of fame when he was later recognized by another kid as the 'robot' guy. This year we're building a Big Daddy from the game Bioshock. All done, so come see the video and construction process.

Designing a Multi-legged Walking Robot

I've started designing a quaduped walking robot. The design will be flexible enough to allow a hexapod to be built using the same components. I'm designing my own boards so you'll be able to make your own. I'm keeping a diary of the development and will share the design when it's done. So hop on board and come along for the ride.

5V Boost Switching Regulator

Here's a little project I put together for a friend. It's a small switching regulator that takes the output of 1 or 2 AA or AAA batteries and boosts it to 5V. Infact the part can be programed for any output voltage between 1.8V to 5.0V using two resistors. If you leave off the resistors you get a 3.3V output. Sweet.

March Break 2011 - Robot Challenge

R/C robots are fine but I like autonomous robots best. For this March Break I'm hoping to host a "Build You Own Robot" party for my son and his two friends. I've built small robots in the past so I thought I would challenge myself to come up with an easy to build, cheap robot "kit" plus code. I have two and a half weeks.

T-Pro SG90 Micro Servo - Continuous Rotation Modification

I'm designing a small robot kit for my son's March break. I'm using some remarkable 9 gram micro-servos that I found on-line for $2.77 US. The first step is to modify these servos for continuous rotation so I can use them to drive the robot. Lot's of pictures show what you can expect.

Building a DALEK Halloween costume - 2010

My son and I make him a Halloween costume each year. In the past he's been such things as an astronaut, a steampunk robot, a man with a fish eating his head, and in 2009 Boba Fett. This year we tried for our most ambitious costume yet; a DALEK from the popular TV series "Dr Who".

LEDactus - Controlling many LEDs with only a few data lines

Everybody loves flashing lights. Here's a design that uses charlieplexing to control a large number of LED's with only a few data lines.

Fabricating a compact PIC microcontroller board

Here's a PIC board based on the PIC18F1320 that you can use for a multitude of projects. Full schematic, PCB patterns and build instructions. This board is used as the basis of the LEDactus project.