Pressure Sensor

Instructions: This outputs the data from the onboard absolute pressure sensor, scaled so that it reads in meters. Move the board up and down by a few feet and see if you can see a correlation in the movement of the displayed data. Don't expect it to be exactly right, just that it moves in broadly the same direction as you're moving the board.

Typical data:

http://ardupilot-mega.googlecode.com/svn/ArduPilotMegaImages/pressuretest.png

Troubleshooting: Translating from pressure to altitude is tricky, given that it is affected by humidty, temperature and wind. Don't worry too much about the absolute numbers; just focus on whether the change correlates more or less with the vertical movement of the board.