When you touch the Bare Paint on either side of the gap you connect the circuit through your skin – don't worry, the current is so low you will not be able notice it. The 555 timer senses voltage change at pin 6 and pin 2, depending on which button you press and flips the output state at pin 3 - turning the LED ON or OFF. By the end of this tutorial you will have painted two touch buttons, with Bare Paint or a Bare Pen, that connect to a touch sensitive ON/OFF 555 timer circuit. Once you have got this simple circuit going you are free to get even more creative in using the paint to make different graphical touch buttons. Please send your electro-art works to us to put up on the community site!
Step 1: Components
LM555 Integrated Circuit
Paper Clip Wires
Step 2: Materials
1. A jar of Bare Paint, paint brush and paper, or use a Bare Pen
2. A 330 Ohm resistor, two +-2.7 Mega Ohm resistors (make sure it is sufficiently large for greater sensitivity), one 10nF capacitor (0.01uF = 10nF = 10 000pF) and a LED
3. Some wire to make your paperclip wire connectors (see Connecting to Bare Paint for how to)
4. Solder-less breadboard and some jump wires
5. Some paper or other non-conductive material to apply the Bare Paint
6. A 9V Battery and a battery clip with wires.
Step 3: Painting the On/Off Touch Buttons
Second, paint your decided button graphic onto your surface with Bare Paint and a paintbrush. I have done this on paper and used a thin piece of masking tape to ensure a clean thin break at my touch points. Below is my finished pair of touch buttons after being left to dry for several minutes. I have made sure that the lines come close to the edge of the paper so that they can be reached by a paperclip.