Anyone ever dissected a compass mirror?

Just wondered what was in it and how the compass itself works (I understand the Earth's magnetic field....yada yada yada)...I'm referring to the compass and its internals.

I have a place thats 1" x 1" that I'd like to put a digital compass/ambient temp guage - and was wondering what was in them before I get one and destroy it....heh heh. 

digital compass modules are usually not cheap in low quanities to buy, last time i looked they where around $60-80

not sure how one would work if pulled out, good luck

You can actually buy them? Where? These are the smaller units as in the mirrors?

Would certainly make more sense than trashing a perfectly good mirror.

well i was just talking about the internal modules like honeywell makes...

or something like this: http://www.junun.org/MarkIII/Info.jsp?item=26#

hmmm its just 2 magnetic sensors, and a microcontroller.... maybe ill make my own...

10 to 1 says I can get a mirror from a Pick n' Pull and have everything for $10.

Building one from components seems a bit complex for me.....maybe in a beer or two (or 5?) it'll make more sense.

If i knew how to build one and knew it would work, I'd give it a shot.

Note....."IF". 

Not Exactly....

The Gentex compass mirror comes in many styles including dimming, compass, temperature and Onstar head.

These mirrors including the ones found on high end GM cars as well as others adjust themselves to the car, the metals in the car and are most accurate.  I took the compass mirror out of my Cadillac before trading it in, replace it with an auto dimm mirror and put it in my Wife's Chevy Van. Works pefectly. The new Cadillac CTS sports model with NAV does not come with the Compass mirror, (something Cadillac is going to change next year), so I purchased an Onstar Compass Temperature mirror taken from a wrecked 2004 Buick, removed the old one, inserted the new one on its post and plugged it in. Then I ran the car in a circle (Factory directions!) three times to callibrate the Compass.... Bingo! Works perfectly.....

BTW, Gentex Corp sells these through Mito Corporation, (can be found on the web), for most cars....