Andrew Tridgell  recommended that I look at pixfalcon as a smaller pixhawk for some

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@Andrew_Tridgell recommended that I look at pixfalcon as a smaller pixhawk for some of my RC planes, so I got one for a bixler 2 build.
I have mixed feelings about it. It looks like good hardware in a small form factor, and I can live with the few limitations like missing I/O ports, but the choice of yet another set of incompatible plugs is just silly, not even using the same ordering for the 3 wires in I2C is beyond silly, and not providing ground and VCC on 7 of the 8 servo cables, is not a good idea if you expect people to use it in planes.

Sadly, those shortcomings combined (not counting some other ones detailed in the blog post, like wires so thin for the analog video on the OSD board that no enough current could reach my camera), make this board quite a pain in the ass to use to be honest (I spent probably 2 days finding and working all those issues, most were unnecessary and none of which are an issue with a real pixhawk).
Virtually all these problems are easily fixable, so I’m hopeful a pixfalcon v2 will fix this, but for my next plane build, I’ll likely buy a different small pixhawk clone, that said the pixracer probably won’t be an improvement there as far as cables are concerned, so are there others I could/should look at?

Here’s my blog post on a bixler2 rebuild with a pixfalcon and Brotronics PowerTowerRX with backup lipo and buzzer:
http://marc.merlins.org/perso/rc/post_2016-07-11_Bixler2-conversion-to-Pixfalcon-with-Micro-HKPilot-Telemetry-Radio-_-OSD-and-Brotronics-PowerTowerRX.html

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I thought I’d recommended a PixRacer actually. The lack of ground on the PixFalcon servo ports is indeed very annoying, although I thought they had fixed that (I received a test one with that fixed)

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@Andrew_Tridgell you told me about both pixracer and pixfalcon, but pixracer was lacking the 8 PWM servo ports which I do use, if I recall correctly.
I’ll have to look at the pixracer more closely though, maybe I can connect 8 to 12 servos to it in some way anyway.

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ahh, I’d forgotten you need more than 6 PWMs

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Yeah, crow flaps is 7 channels, then
a) video switcher output
b) pan/tilt servo #1
c) pan/tilt servo #2
d) turn off FPV and cameras via relay
So that’s 11 channels right now although I use a few directly off openlrs receiver.
But maybe I can look into a PPM to PWM hub or SBUS to PWM converter for channels past 6, as I’d feel weird having one flap on the pixracer and the other one on my RC receiver.
Either way, I will give pixracer a look considering that wiring on pixfalcon was such a pity.

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Has anybody tried using SBUS servos on Pixracer?

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For what it’s worth, I also have those extra channels internal to AP:

  • geofence
  • mode switch
  • RSSI as PWM
    So I actually run into the 12 channel limit via PPM which seems to be a current bug of ardupilot on pixhawk (if I use SUMD instead, I get 16 channels from my openlrs receiver instead of just 12).
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@Mark_Whitehorn I have not, but I have lots of existing servos and replacing them with expensive SBUS servos is not really something I’m interested in.

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@Andrew_Tridgell what do you think of the pixhawk lite? http://www.rcgroups.com/forums/showthread.php?t=2418029 it looks interesting, although I’m not about to buy something from goodluckbuy again, but I’m hopeful you can get one from elsewhere?
http://diydrones.com/forum/topics/pixhawk-lite-vs-px4mini-vs-pixfalcon