The Cowtown Computer Congress

Early in October, I found a spooky life size robotic butler at a yard sale, and I couldn’t help myself. The robot has servos to move the head, the eyes, the chest (breathing), and a speaker mounted in the chest. Out of the box, the robot would say things and move its head and eyes when someone walks by, but I don’t like keeping things working as they do out of the box.

Me with Gustav right after I took him out of the box (and gave him my hat)

Immediately after I got home, I cut the wires running from the base of the robot where the microcontroller and motion sensor are to the body of the robot where all the servos are. After some discussion with CCCKC members, I decided the first hack for this would be to hook the eyes and the head to a remote control. To do this, I bought a $15 remote control car from RadioShack and clipped the wires. A little soldering, and I now had a remote control for the robot’s head and eyes.

There was still the chest servo that I wanted to hook up, but the car’s radio only had 2 channels and I was already using them both. The chest servo was originally activated during a “sleep mode” in which the robot would start snoring. Since snoring isn’t very scary, I decided to just have this servo move in and out on its own. This required the design of a circuit. Since I have next to no experience designing circuits, this cheap hack requires 3 separate battery packs, but hey, it works.

Here is the circuit that makes Gustav's chest move in and out

This circuit is a 555 timer hooked up to a DPDT relay via a transistor. The result is the servo moves in one direction for about 4 seconds, and then switches and moves the other direction for 4 seconds. As I said, it’s a cheap hack, but it works.

I ended up lending the robot to a not-for-profit haunted house in North Kansas City, and it was a huge hit. I plan on putting this robot in the hackerspace for anyone to hack, so ideas are welcome in the comments.