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Old Oct 13, 2011, 06:13 AM
dave1993 is offline
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RC beginner
New York
Joined Oct 2008
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Originally Posted by simonk View Post
The 48/88 isn't really a huge difference, so maybe that, too, if any are in production. I'd rather focus on existing boards
actually except for pinout the m88 family is radically different. far more hardware features. 2x more pwm is of particular interest to us. also incompatible from binary standpoint due to completely new io and ram map. c/ardu guys may not notice because these details are hidden from them.

i agree about staying with m8 controllers due to availability (The Chip That Wouldn't Die!!). i've seen a few 8051 boards but personally not run into an m88 yet.

Originally Posted by simonk View Post
The only reason we're talking about this is because quax DID start from scratch
i was under the impression his flea was based on a previous homegrown design. i had copies of a schematic and source but dont recall the fellows name or if he was still alive. not sure because it was couple years ago. in any case quax spoke english and was still around.

Originally Posted by simonk View Post
Current sense by Rds[on] of a FET, really? Do you have any reference for this? It would be possible, I guess, but I'm not sure what would be used for the other side of the comparator in this case.
IIRC there were a few attempts in one of the huge DIY threads. again. it was a long time ago. has to be the same comparator circuit as bemf?

i have a few stolen images (some from ref design kits and couple inhouse leaks) and two of them i was told had protection via Ron. one was emax variant. i was directed to two particular bytes that set limits and sure enough it did change the stall shutdown point. it seemed too small to be bemf timeout. did not have source and never really got into the software end myself so cant say for sure.

it would be the only way to do current sense since there is no resistor in the cheapies.

Originally Posted by simonk View Post
All of the FET frying that I did do was a while ago when I was first working on this tree, and seemed to happen at weird times like when splashing into puddles, not when landing upsidedown at full throttle, which I did try a few times.
i notice this too. my only two burnouts occurred when esc got soaked landing in wet grass (i only fly pre-dawn). never during a crash. rx also get wet and quit. drying in the sun always brings them back though.

BTW thanks for putting so much effort into this project. i intend to give it a try when i get a chance.
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