I am setting out to build an arduino satellite tracker to literally point out location of visible satellite passes, maybe with a laser pointer, maybe just a stick! I have a simple pan-tilt servo setup more or less working but the hard part is locating the satellites. The math is hideously complex but it's a well understood problem and has been nicely solved for me.
This post from last year http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1266005281 has code that should do exactly the calculations I need but I'm not getting correct results. The google project repository at http://code.google.com/p/qrptracker/ has the library and a nice sample with intended results for comparison. It compiles fine but unfortunately the output doesn't match the predicted result.
AZ:333.40 EL: -47.26 RX: 435293340 TX: 145922233 Sat Lat: 28.58 Sat Lon.: 145.88 RR: 4.58 Should be: AZ:57.07 EL: 4.05 RX 435301728 TX 145919440
I'm hoping the original author spots this or that someone else has tried this and gotten different results so we can compare notes. Alternatively, there's a basic language version of the algorithm written for the BBC microcomputer basic that i could maybe use to bughunt the qrptracker arduino code if anyone has a copy of bbc basic they could let me use.