This section gives some basic electronics and robotics information along with helpful links. I also detail a lot of my projects. For most of them I've included schematics. I use ExpressSCH for drawing them and ExpressPCB for designing circuit boards. They are a free package from expresspcb.com. You can download for free and get your boards professionally manufactured for very reasonable prices. Of course, with the final layout you can also etch your own boards at home if you choose.
December 17, 2009
Monsters vs. Aliens
My friend, Phil, approached me one day and said that his daughter's dance team was working on a project that he thought I might be able to help with. They needed to build a robot from "Monsters vs. Aliens" that had a large eye that would pan left and right and an iris that could change from blue to red with a switch. As chance would have it, I had recently been learning about servos and controlling them with circuits built around a 555 or 556 timer chip. This would be perfect for panning the eye which we built from an eight inch diameter styrofoam ball
The iris presented a little more of a problem. I decided to wire a series of eight red/blue LED's in a circle. Switching them would be no problem, but even running off of a 9 volt battery, there wasn't enough voltage to keep them bright. After doing a little research, I found a schematic for a charge pump. This circuit uses a specific chip and several capacitors to bring the input voltage up from 9 volts to 33 volts. It worked perfectly. Here are some pictures and video clips.
This is the schematic for the servo controller. The 556 chip functions as two 555 chips which control the degrees of rotation and time between movements.
Here's the board I wired to control the eye movement. The three pins in the top left hook to the servo and the two on the right connect to the battery.
This is the schematic for the charge pump.
The charge pump bumps the voltage from 9V to 33V.
Here's the servo control board mounted inside the framework of the monster.
This picture shows how the iris control board was mounted directly to the eye.
The board with the LED's for the iris was mounted on the front side of the styrofoam eye.
The eye with the blue LED's activated.
The eye changes to red when a switch is flipped.
This video shows the eye turning before the front was added.
The front has now been added and a plastic difusing lens will eventually cover the opening.
Other Projects
My second microcontroller project - June 18, 2011An audio controlled servo - June 1, 2011
My first microcontroller project - May 17, 2011
I built a motion controlled cat fountain - March 24, 2011
A basic line-following robot - March 11, 2009
