Capacitive Touch Sensors on the Raspberry Pi

Capacitive touch breakout boards are an excellent way to use household objects as inputs on your Raspberry Pi. Any conductive object can act as a switch when connected to sensor boards, including potatoes, apples, spoons and pencil graphite.

The capacitive touch sensors detect when you touch the board's pad or an object connected to the board. Humans carry a small electrical charge. When you touch a capacitive touch sensor it will detect this charge.

With some simple wiring to the Raspberry Pi and a few lines of Python, you've got a fun and easy way to control your projects and games. For example at the end of this guide we'll show you how to control Minecraft: Pi Edition using a apples.

There are three breakout boards that this guide will show you how to use with your Raspberry Pi.

	Momentary The momentary capacitive touch sensor will be active as long as something is touching it. The LED shows whether a touch has been detected. The board has a large touch-pad. The small copper hole near the touch-pad can be used to connect the board to capacitive items such as a drawing made with pencil graphite.
	Toggle The toggle capacitive touch sensor will activate when you press it and deactivate when you press it a second time. The LED will light up to indicate whether your touch has been detected. Like the momentary sensor, this sensor has a large touch-pad. The small copper hole near the touch-pad allows you to use a wire to connect your board to everyday objects, like a spoon, which can then be used as an input.
	5-Pad The 5-Pad capacitive touch sensor offers a total of 5 inputs on one board. It is very similar to the momentary board, but includes more inputs. Unlike the other boards it does not have any pads, instead the pins on the right of the board are used to detect touch. These pins can be connected to wires, which can be attached to everyday objects, like bananas.