Turn almost anything into a keyboard or mouse! MaKey MaKey allows you to turn everyday objects into touchpads and combine them with the internet. It's a simple system for beginners and experts doing art, engineering, and everything in between.
Note: This is a BareBones MaKey MaKey — the PCB by itself. You will need to provide your own alligator clips and a mini-USB cable at the very least (some Male-Male jumper wires are recommended too). If you don't have those parts already lying around, get one of these turnkey kits instead: MaKey MaKey Standard Kit or MaKey MaKey Deluxe Kit (the Deluxe Kit has 14 alligator clips instead of seven, and includes a roll of copper tape).
The MaKey MaKey printed circuit board has an ATmega32U4 microcontroller running Arduino Leonardo firmware. It uses the Human Interface Device (HID) protocol to communicate with your computer, and it can send keypresses, mouse clicks, and mouse movements via USB. Digital output pins are available for controlling electronics directly as well. For sensing closed switches on the digital input pins, high-resistance switching makes it so you can close a switch even through materials like your skin, leaves, and Play-Doh. Any material that can conduct even a tiny bit of electricity will work: most foods, plants, pencil graphite, coins, aluminum foil, animals, etc.
The board uses a pull-up resistor of 10-50 MΩ. This technique attracts noise on the input, so a moving window averager is used to lowpass the noise in software, saving money on hardware filtering.
Default inputs — no programming required There are six inputs on the front of the board which can be attached to objects via alligator clipping, soldering to the pads, or any other method you can think of. These inputs by default provide arrow keys, space bar and left-click signals (see top picture). There are another 12 inputs on the back which you can access with jumper wires via the female headers (see lower picture). These inputs by default provide keyboard W, A, S, D, F, & G signals, and mouse up, down, left, right, left-click, & right-click signals.
If you wish to use a different set of keys, or otherwise change the behavior of your MaKey MaKey, you can simply reprogram it using the Arduino environment. By cutting a trace on the back of the board, you can disconnect the large pull-up resistors if you want to, which may be necessary for a small minority of Arduino projects.
The back side of the board also has a female header providing 5V digital output options allowing you to connect MaKey MaKey to things like relays, motors, or other electronics projects instead of to a PC.
Arduino Compatibility You can use your MaKey MaKey board in "Arduino mode" at any time. This would allow you to spin motors, turn on LEDs, or anything else that an Arduino can do. If you want to learn to use Arduino or other electronics, but want to start without any programming or breadboarding, MaKey MaKey is a good starting point. There's no need to understand Arduino in order to use MaKey MaKey.
Videos of MaKey MaKey Usage
MaKey MaKey Resources