Directional antennas

Paul, my neighbour, built a small gadget which I thought impressive enough to blog about.  It's based on an arduino and a fluxgate electronic compass.  The aim is to keep a payload, e.g. a directional antenna (wifi or TV antenna for example) facing in a constant direction, even on a swinging boat.

The base is fixed to the boat, the payload sits on top, and the gadget sits in the middle, reading from the compass and driving a small motor to keep the payload facing in the same direction.

Here are some front, top and side photos:

The arduino board is mounted on top of the gadget, it's a standard type of arduino board, the entire thing is powered through a USB adapter.

Mounted under the arduino board is the fluxgate compass.  I guess you could feed in NMEA data from an existing on board fluxgate but the one mounted here is so tiny it forms part of the unit.

Here's a video of the thing in operation: