One of the recent projects at Swansea Hackspace has been using an Arduino and GRBL to control a milling machine, which can be controlled using key presses to move the machine head to its starting position. It would be nice to have some physical controls that can be used for this purpose, which can be done using some recycled materials and a Makey Makey.
Step 1: Prepare some materials
Thin metal sheeting can be (carefully) obtained by dissecting an empty drinks can.
Other materials you will need include:
Step 2: Prepare controls
Carefully mark up and cut control surfaces from the metal sheet.
Scissors and a Stanley knife seemed to work well
Step 3: Check that the Makey Makey can detect key presses
Connect your newly formed controls to the Makey Makey using the crocodile clips supplied with the kit, connecting yourself to the earth/ground bar of the Makey Makey.
Plug the Makey Makey into your computer and check that the appropriate LEDs on the device light up when you touch the control surface. Your computer should also respond to you pressing the surface.
It might be necessary to scrape away some of the coating from the surface of the metal pieces in order to get a reliable connection.
Step 4: Mount controls into a sturdy IP rated housing...
...or go back to the recycling bin the can came from and acquire some cardboard and secure the controls to it using double sided tape.
It might be easier to mount the controls to the cardboard by securing small pieces of wire to each control and passing those wires through a hole in the cardboard.
Step 5: Connect everything to the MaKey MaKey and test!
If you need to remap the inputs on the Makey Makey to generate different key presses, go to the online remapping tool
Older Makey Makey devices can be remapped using the Arduino IDE.