Download this template, print it, and gather supplies. You'll need conductive tape and an LED for this project. You can use any conductive tape, but we used tape from our Inventor Booster Pack. 

If you need help with your template, watch this video!

Use a hook up wire in the back header and plug into "KEY OUT". 

Use an alligator clip to connect this header to your KEY OUT tape trace on the template. (The red alligator clip connected to the heart, is connected to KEY OUT on the Makey Makey) Connect the template to EARTH where indicated. (The grey alligator clip on the heart is connected to EARTH.)

Lastly, hook up any key press you would like for the "testing materials"  tape trace that says "key press" (We connected the red alligator clip from any key press to SPACE on the Makey Makey!) Make sure you connect EARTH for the testing materials tape trace too.

Plug your Makey Makey into the computer.Use your finger to make sure the heart will light up when you touch both tape traces! Now you are ready to test materials!

Ohm Resistors 

You will need an ohm resistor in your Makey Makey circuit so you don't blow out the LED. To figure out what ohm resistor you need, you have to use Ohm’s Law. That formula is V = I × R, where V is the voltage, I is the current, and R is the resistance.

Check out this table from Evil Mad Scientist.

Makey Makey output is between 4.5 - 5V, so for a Blue, Green, White, or UV LED, you will want to use a 48 ohm resistor. 

If you are using a Red, Yellow, or Yellow-Green LED, you will want a 36 Ohm resistor.