Colin O'Flynn
Archive · old wiki · last edited October 2011

Digital Compass Module

Archived from the site that ran here before WordPress, and reproduced as written — links and prices and "coming soon"s included. Nothing on this page is maintained.

This compass module contains the new (cheap) HMC5883L 3-axis magnetic sensor module from Honeywell, and combines it with a 3-axis accelerometer and AVR microcontroller. At the time I wasn’t aware of a cheap chip with the accelerometer/magnetic sensor all in one, the LSM303DLH.

In small quantities this board could be SOLD for about $20, so it’s much cheaper than other tilt compensated compasses. I’ve been slowly working on algorithms to do all the required compensation. Not just tilt compensation, that is easy, but hard and soft iron compensation to calibrate out errors resulting from your environment.

Here is a photo of my test setup: