This M&M dispenser includes:
1) A large light up button with 12 Neopixels that can display patterns of color to provide instructions and feedback to the subject
2) A hopper to dispense M&Ms
3) An output jack to connect the M&M dispenser to other research equipment such as an eye tracker or a doomsday device
Thank you for the great design, I printed a copy and stuck an esp8266 in it for wifi control :)
https://www.youtube.com/watch?v=1WX6Xi6UPiY