This Creepy Mask Gives Alexa a Face
Keith Colton's animatronic project imitates the voice coming from an Echo Dot using an Arduino Nano and an envelope detector.
Alexa devices can be useful as a sort of disembodied voice, but what if you had an actual moving head that mimicked its voice output? That’s the idea behind this animatronic mask made by Keith Colton for last year's Dublin Maker Faire.
The mask takes in sound signals from an Echo Dot via a 3.5mm stereo jack. It passes this to another jack for audio, along with a non-inverting amplifier and envelope detector circuitry, before being sent to an Arduino Nano’s ADC pin. The Nano then takes this signal and converts it into a servo outputs that actuate the mouth. There’s an additional servo for neck movements and a third for the eyes.
Mechanically, the build uses a plain white mask with the bottom mouth portion cut to allow the motor to move it to form words. A mostly wooden frame, plus some bent metal, supports the mask and eyes are linked together by metal wire. A neck servo is attached to the base via its horn, turning the servo itself with the mask.
You can see it speaking in the first video below. The second mostly shows off an array of ultrasonic sensors that were envisioned for tracking, but were never fully implemented. It does, however, contain a clip of the mask "playing cards" at around the 3:00 mark.