How to measure your true heading with a HMC5883L magnetometer

The HMC5883L magnetometer communicates over an i2c bus, and will run off between 3 to 5 volts. So you’ll only need four wires to hook it up to an Arduino ProMicro. RAW is wired to 5V (assuming your input supply is 5 volts), pin 3 to SCL, pin 2 to SDA and GND goes to GND.

This is a companion discussion topic for the original entry at