Re: BMMCC PWM Specs
Posted: Sat May 14, 2016 3:31 pm
Hi Kim
I'll do more tests on this and you may be correct - that it seemed to be really picky about the values could possibly be related to the fact my sketch is perhaps a bit all over the place in terms of the frame timing - I just tried to get it to work without worrying too much about how various part of the code that process input commands might have effected sending a very regular frame timing (or - maybe I lucked out and it is pretty much in spec and I'm overestimating the code execution overhead)
I found I had to put the 2 frames that did the UP/DOWN right after each other and I used a very guessed at delay of 6ms in-between (based on the supposed spec being a frame every 14ms or so and trying to guess how long the actual frame write took at 100k baud)
certainly last night it only stated working reliably when I did use those exact values on UP especially, but I'll see if I can get it to respond reliably to a wider range
the library I linked to seems designed for a controller that sits in-between a normal sbus receiver and whatever its controlling so it can also read a signal and pass that through, etc - you would probably want to keep a lot more of it intact than I did if running with real sbus gear in the mix
I'll do more tests on this and you may be correct - that it seemed to be really picky about the values could possibly be related to the fact my sketch is perhaps a bit all over the place in terms of the frame timing - I just tried to get it to work without worrying too much about how various part of the code that process input commands might have effected sending a very regular frame timing (or - maybe I lucked out and it is pretty much in spec and I'm overestimating the code execution overhead)
I found I had to put the 2 frames that did the UP/DOWN right after each other and I used a very guessed at delay of 6ms in-between (based on the supposed spec being a frame every 14ms or so and trying to guess how long the actual frame write took at 100k baud)
certainly last night it only stated working reliably when I did use those exact values on UP especially, but I'll see if I can get it to respond reliably to a wider range
the library I linked to seems designed for a controller that sits in-between a normal sbus receiver and whatever its controlling so it can also read a signal and pass that through, etc - you would probably want to keep a lot more of it intact than I did if running with real sbus gear in the mix