In this tutorial we are going to make a simple potentiometer using a strip of Bare Paint. This is one of the fundamental ways to use the material as it makes a great variable resistor. The principle of the interaction is to vary the voltage received by the wiper based on its position on the pad of paint. For this tutorial you'll need some Bare Paint, a piece of paper, an Arduino and some jumper wires (or any wire that can connect the Arduino). The potentiometer is one of the fundamental ways to use the material and in the future we'll be doing more tutorials which show you how to use this simple interaction as a cool and flexible interface.

To help you complete this project we've made all the component available to buy in the Arduino Mini-kit. Alternatively you can source them yourself via the links below.

Materials

To purchase the Mini-kit with all the components click here

Bare Paint
Paint Brush
Paper
Arduino  UK: RS Farnell Arduino.cc  US: Jameco Sparkfun 
Jump Wires  UK:  Maplin  US: Sparkfun 
USB Cable  UK:  RS Farnell  US: Jameco Sparkfun

Arduino code below. Copy and paste into a new Arduino sketch, making sure to select the correct board and serial port.

/*
Making a potentiometer with Bare Paint
Attach one wire from +5V to one side of a pad of Bare paint
Attach second wire from Ground to other side of same pad of paint
Wire connected to Analog Pin 0 acts as wiper
*/

int sensorValue = A0; // This is the wiper which moves along the pad of Bare Paint it is connected to Analog Pin 0
int ledPin = 9;//  This is the LED which we will be dimming.  It is connected to pin 9 and ground.

void setup()
{
  Serial.begin(9600);  
}
void loop()
{
sensorValue = analogRead(A0); // Read the value from the wiper 
ledPin= map(sensorValue, 0, 1023, 0, 255); // map the value from the wiper (0-1023) to the range of the LED (0-255) 
analogWrite(9, ledPin); // Change the brightness of the LED based on the remapped values received from the wiper   

Serial.println(sensorValue); // print the values to the serial port
}