HM55B Example Board

Chuck Rice

Since people are talking about the HM55B compass, I thought that I would post the sub-board I am making for my Propeller. I first wired it up using point to point on a round Radio Shack proto-board (not great quality boards, but workable). I liked it, so now I have created an Eagle schematic and board and converted the board to G-code and am working on geting it milled out on My Sherline CNC system. (Attached is a picture of my first try at milling a PCB. No holes yet because I did not have the right drills)

I have attached several pictures and my test code. Since this is test code, there are still lots of debug things in it, but I think it will show how the board works.

One thing that amazed me, even though I expected it was to see how much the compass direction changes when the HM55B is tilted outside of the horizontal plane.

Post Edited (Chuck Rice) : 4/12/2009 12:38:43 AM GMT

Philldapill

Very nice, Chuck. Just curious, what's the response time of the compass when you move it around. A normal compass takes a second or two to re-align with the magnetic field. Is this nearly instant?

Chuck Rice

There may be a little lag, but it is not perceptible. Each LED covers covers 22.5 degrees, so you have to turn it a bit before the next LED lights, but if you move it back and forth on an edge, the light jumps back and forth without perceptible delay.