This wonderful device was created for an independent research project I did one semester. I built a magnetometer array to evaluate the effectiveness of using it for quick IED detection in cars. Funding was through the Dept. of Energy, and I had to give a presentation to some guy from the army when I was done with it.

The “tube” consisted of 2 Picaxe-18X microcontrollers and three 3-axis SPI Magnetometers purchased from


This is a close-up of the 3-axis MicroMag Magnetometer module.


The circuit boards all wired together, each spaced about 8 inches apart


Here you can see the finished “tube” hooked up to a laptop with recording software.

But what you can you do with it?

It’s designed to be swept over an area at a fixed speed. The “tube” samples the overall magnitude of the magnetic field at three different spots at a sampling rate of a few hz, and reports it back to the laptop over a 9600 baud serial link. This data can be used to detect disturbances in the earth’s magnetic field (ostensibly like those created by jury-rigged artillery shells containing a lot of iron).

If you’re really interested…

The Presentation I gave when I finished the project

Source code for master 18X uC

Source code for slave 18X uC

The master node controls 2 magnetometers and communicates directly with the laptop, while the slave node controls 1 magnetometer and communicates back with the master. A 2nd magnetometer could be added to the slave pretty easily for higher resolution.