Part3:DIGITAL LPG METER PROJECT: Measuring and caculating

-which wires do we use on the LPG Switch?
-what values do we measure on those wires (empty and full tank)

The Arduino can be used for all kinds of projects. It's perfect for in car use because of its wide power input range. The car (or other vehicle) has 12volts. The arduino can be used on this voltage without any customization. It's an ideal platform for you project.