You may rightly question the logic behind using apples as switches for your Raspberry Pi, as against the usual hard plastic ones. Well, for one, we live in an analog world and there is much more fun in integrating items of daily use with your computer. For another, it pays to see the look of astonishment on someone’s face when picking an apple from a basket, if the computer were to reprimand him.
The tiny credit card sized single board computer, the ever-popular Raspberry Pi or RBPi can sense inputs with capacitive touch breakout boards. This is the basics of using several household objects as input sensors for the RBPi. You can use any conductive object, not only an apple, such as pencils (the graphite part), spoons and potatoes including any other fruits or vegetables that you may find handy.
Capacitive touch sensors detect the tiny amount of electric charge every human body carries. The breakout boards have a pad that is sensitive to touch. You can extend this pad to any object by attaching a wire, allowing the object to develop a sensitivity to touch. You will of course need to inform the RBPi of your intentions and to do that, put in some effort in programming it. Get help from this website.
With the hardware above and a few lines of Python, you will soon have a new way of controlling your projects and games that is fun and easy at the same time. There are three types of breakout boards that you can experiment with.
The first type is the momentary capacitive touch sensor. This detects as long as something continues to touch it. The sensor has an LED that glows when anyone touches the pad and remains lit until it detects the end of touch. This breakout board has a large touch-pad and a small copper hole near it. You can solder a piece of wire to the hole and extend it to a capacitive item such as a drawing you have made with pencil (graphite).
The second type of breakout board is the toggle type of capacitive touch sensor. The LED on the board comes on as soon as you touch its pad. The LED remains lit up even when you lift your finger off the pad. The LED will go off once you touch the pad again. Therefore, when you solder a piece of wire to the hole near the touch-pad and connect its other end to any conducting item such as a spoon, you can easily detect if someone has touched the spoon at least once.
The third breakout board is the most versatile of the lot. Surprisingly, it does not have any touch-pads, although it is named as a 5-pad capacitive touch sensor. Instead, it has five copper holes, so that you can connect five objects with five pieces of wire. Therefore, if you have five different fruits or vegetables, you can connect them up and the RBPi will help you to chart their individual responsive speeds against touch.
While the two boards will both need a 10K resistor each connected between the object and the board, the 5-pad touch sensor board does not require any resistors, as it has them on-board.
