Minion Stuart

Are  you a fan of the Despicable Me movies? Eagerly awaiting the release of the Minions prequel movie this summer? Time to build your own Minion. You know you want to!

There are three versions of these great Minion toys, Stuart, Dave and Tim. I fell in love with the Stuart version as soon as I saw it. When you move the head left-right or back-front, the eye moves and the silicon rubber skin morphs into different expressions accompanied by cool sound effects. Each Minion has its own custom sounds related to the specific character from the movie. These toys are a joy to play with and an open invitation to hack... and so I did.

I initially thought I could just add servos to the existing gimbal mechanism that controls the front-back and left-right movement. Unfortunately there was no room. I had to replace the main mechanism with two standard servos. The eye mechanics were not too hard to integrate to two mini servos. 

I was pretty happy with the eye and eyeylid servo control, as well as the front-back and left-right body control. However, I wanted to go beyond that, so I added two more mini servos to control the arms, which were posable, but not tied into the original mechanism at all. As a result, Stuart looks a bit wider than normal, but still acceptably Minion-like.

An Arduino Nano controls the motion via six servos. I'm especially proud of the eye and eyelid motion, which I feel adds a lot of character. Another digital output is tied to the original sound board via a Vishay SFH615A optoisolator. The board fires a random sound effect. I'd like to eventually replace it with a sound board that will let me play specific clips of Stuart's voice, but this will do for now. 

The video show the initial results. More to come!

I'll attach the code once I've cleaned it up a bit.