2V Input Signal
Some position sensors output a 12v signal. To correct this, and avoid damaging the Arduino, a circuit like the one in the diagram can be constructed. The resistor R1 is not always required, but will make sure that any output that is not high is pulled low. Along with this circuit use the pull-up jumper on the Speeduino. This will effectively change a 0v/12v into a 0v/5v signal.