The final project for the Critical Making course is wearable technology. So this is a tutorial on a simple capacitive touch sensor.
A big resistor 1M-10M
Step 1. Download the Capacitive Touch library from the Arduino web site
Step 2. Install the library on your computer.
Step 3. Cut a piece of tin foil, about 5cm square is enough.
Step 4. Cover the centre of the tin foil with tape. Don’t go all the way to edge. You’ll need some bare tin foil to connect it to the Arduino.
Step 5. Wire up the Arduino according to the diagram below.
Step 6. Copy the following program to your Arduino editor and run it.
Step 7. Watch how the readings change in the serial monitor. Type in a number to use as a threshhold between two states (touched and not touched.)
Step 8. Profit!