Sometime in 2014, I attended a Cincinnati Reds baseball game with my daughter. They were giving out free bobblehead dolls as part of a promotion. Probably I would have been unable to convince my daughter to attend a baseball game if it were not for this promotion. Anyway, we both got Aroldis Chapman dolls, and they both broke on the way home. My bobblehead didn't have enough hot glue to keep its head attached to the spring on the inside, and my daughter's Aroldis Chapman's hand fell off.

I had some spare parts lying around, including a Netduino, an RGB LED, a small servo motor, and a Happ arcade button. The disembodied Aroldis head might be a good centerpiece for another microcontroller project.

I put the RGB LED inside the bobblehead and drilled out the eyes so that the LED's glow would shine out eerily from the eye sockets. I hot-glued the RGB LED in place. Next, I drilled a hole through the center of a cylindrical scrap piece of wood and fed the RGB wires down through a hole, and mounted the head to the wood. It looked like a weird chess piece at this point.

I mounted the servo motor in the enclosure (Liquid Nails and Sugru) and attached it to the bobblehead/chess piece.

I ordered some other Happ arcade buttons and learned a bit about how to wire them up.

My original thought was to make the project into a simple program-and-playback interaction. Press the Red button 3 times and the Blue button once, and then play it back. This sounded more fun to me at the time than it does now that I'm typing it out.

Then I thought maybe a Simon-like game would be more fun.
  1. Red Button: Red LED
  2. Blue Button: Blue LED
  3. Green Button: Green LED
  4. White Button: Rotate Head Left
  5. Yellow Button: Rotate Head Right
  6. Black Button: Start new Simon game

If you get the pattern wrong, Aroldis shakes his head back and forth a couple times in disapproval. The "playback" of the pattern gets progressively faster, starting with a delay of 800ms per step, reducing the delay by 10% for each new step added

I'm pretty pleased with the result. The pic shown above does not show the 9v battery wired up to the toggle switch, but that was done later.


Source code is available on github at :

Comments or questions, please email joetcochran AT gmail DOT com