Analog Devices is about to start selling a very cool-looking device: a small box that combines three-axis gyros with three-axis accelerometers, along with an embedded processor to massage all that data and deal with calibration and drift issues. Called the ADIS16355
, it will retail for about $300, which isn't cheap, but when you consider what it would cost you in time and money to duplicate that functionality, it seems more than worth it.
Not sure what accelerometers and gyros are good for? They're what's needed to build an Intertial Measurement Unit (IMU), which is the core of a proper autopilot. Tom Pycke has a great series of blog posts that explain all this in lay terms (at least at the beginning--then it gets into math):
If you're contemplating building your own autopilot or taking on one of the open-source ones
, these posts are the right place to begin.