Hi,

I have an APM1 and an APM2, with ArduPlane 2.33 on them. Communicate fine with Mission Planner. Well sometimes the "connection" breaks down and I can't reconnect but that is another story..

Now I want to play with my own mission tool, and have that communicate with the APMs.

I have logged a little data from the APM2 serial stream, excerpt shown here in hex dump (and more is attached):

00000300: 0302 7861 5524 0101 2204 2760 dc83 ee55  ..xaU$..".'`...U
00000310: 3325 0101 fe01 4465 6d6f 2053 6572 766f  3%....Demo Servo
00000320: 7321 93d5 5503 2601 0101 0302 db91 5527  s!..U.&.......U'
00000330: 0101 2204 2760 dcfd 3655 3328 0101 fe01  ..".'`..6U3(....
00000340: 0a0a 2052 6561 6479 2074 6f20 464c 592e  .. Ready to FLY.
00000350: c564 5529 0101 2202 0404 2760 dcdc c455  .dU).."...'`...U
00000360: 042a 0101 9812 7820 ca19 5502 2b01 012a  .*....x ..U.+..*
00000370: cf8b 5525 2c01 0120 f806 3001 4309 461c  ..U%,.. ..0.C.F.
00000380: 3c63 5655 652d 0101 d855 122e 0101 4902  <cVUe-...U....I.
00000390: 1728 f47a 5510 2f01 0125 0384 04b0 04b0  .(.zU./..%......
000003a0: 04b0 bf55 1130 0101 2303 8404 b004 b004  ...U.0..#.......
000003b0: b004 b004 b004 b004 b001 5355 2031 0101  ..........SU 1..
000003c0: 1ef8 3c64 401c c82d ba1f e190 ba49 bd30  ..<d@..-.....I.0
000003d0: 396f 1cd3 4655 1432 0101 4a40 351e b801  9o..FU.2..J@5...
000003e0: 8e55 1c33 0101 a33a f7ca d1bb 17b9 46f0  .U.3...:......F.
000003f0: be3f bb56 f098 5e55 0334 0101 a565 8c55  .?.V..^U.4...e.U
00000400: 1035 0101 2503 8404 b004 b004 b069 e455  .5..%........i.U
00000410: 1136 0101 2303 8404 b004 b004 b004 b004  .6..#...........
00000420: b004 b004 b001 3bbc 5520 3701 011e f9d1  ......;.U 7.....
00000430: d83a 603a 14bc 9c80 b5bf aaa6 163c 19ce  .:`:.........<..
00000440: 25be 39e4 b93a b756 57f2 f155 1438 0101  %.9..:.VW..U.8..
00000450: 4a40 28f6 018d 5510 3901 0125 0384 04b0  J@(...U.9..%....
00000460: 04b0 04b0 d44b 5511 3a01 0123 0384 04b0  .....KU.:..#....
00000470: 04b0 04b0 04b0 04b0 04b0 04b0 01fa d255  ...............U

Now I wonder what message format is really used after all?

It can't be Mavlink 1.0 on the format described here:

http://forums.ni.com/t5/LabVIEW/Interfacing-Ardupilotmega-with-Labv...

because I see wildly varying system and component IDs and invalid message IDs, and the CRC never matches. I have used a home made Java program to try decode this data and the program works fine with binary data generated by the Pixhawk Python code generator code, for MavLink1.0 with the extra-field-hash-CRC thing enabled. Field reordering is not an issue; I am not even that far yet.

It can't be the ArdupilotMega binary protocol either, because I never see 0x3444.

What format is this data...?

Kind regards

Soren