Developers frequently use magnetic sensors in consumer products, such as to provide compass and navigation services in portable devices. In theory these sensors can be read directly to provide direction data. In practice, however, it’s not always that easy to obtain accurate information.
In this article, Mike Stanley explains the scientific theory relating to hard and soft magnetic cores, and how their presence can effect the accuracy of magnetic sensors in embedded systems.
Via the Freescale blog.
affect, not effect