Magnetometer Accelerometer project question

I want to build a small wooden box that I can place an object into. The object will be magnetic (a strong rare earth magnet will be affixed to the inside of the object). The bottom of the box contains an accelermeter/magnetometer sensor package. I would like the box to determine:

  • If the magnetic object was placed inside of the box
  • Orientation of the box
  • If possible, I would like to be able to tell one magnetic object from another (ie, based on the gaussian signiture of the object)
  • If possible, the polar orientation of the object containing the object

There are several accelermeter/magnetometer sensor packages available...any recommendations that would meet my needs?



I think the magnetometer will go out of range.

With a magnet nearby, the magnetometer can no longer detect the earth magnetism.
Detecting the polar orientation of the magnet is no problem. But the magnetometer detects the 'field', so if the magnet is in a slighty different location, the angle of the magnetic field changes.


Thanks for the reply. I don't really care to deteremine the position of the magnet. The number one requirement is whether the magnet is in the box (say dimensions of 10cm by 10cm by 10cm). So if the strength of the magnet overwhelms the sensor's sensitivity it is not an issue as long as the I can tell of the magnet was sensed.

If I could get direction of the pole or a reading of the gaussian value, well that is icing on the cake.


I have an HMC5883 3-axis magnetometer. I have it on a robot. In my shop I have a couple of pretty strong magnetic tool holders. If my robot gets within about 3 feet of the magnets I start to get heading errors, so I don’t see a problem sensing only a few inches away.