Note: The HMC5843 magnetometer has been discontinued, please go here for the new part.This is a 3-axis digital compass board based on the Honeywell's HMC5843. Communication with the HMC5843 is achieved through an I2C interface. The board has an I2C translator and 3.3V power regulator that make it compatible with 3.3V and 5V applications using a solder jumper. This magnetometer can be used on the ArduPilotMega IMU Shield, the UAV DevBoard, ArduIMU+ or any microcontroller. By adding this accessory to your APM set up, you will give your vehicle and extra sense direction! This revision reduces the overall size of the board while keeping all of its previous features!