[trust]

OrangeRx receivers - at least 8 or 9 channel with s.bus output - don't seem to be available anymore.
Spektrum offers SRLX2 output - can this work with the SRXL configuration on Librepilot?
Frsky offers S.bus, but it's inverted? Is there an option in configuration to use inverted?
I have both a TX16S and a Futaba T9CHP with a Spektrum module (old DSM2), so I can use pretty much any xmtr format. But I really prefer the serial outputs to feed into the flight controllers. MUCH simpler hookup.

[TheOtherCliff]

A little info about SBus protocol.  The standard SBus protocol is an inverted serial protocol.  There is a configurable hardware inverter built into LP compatible FCs on MainPort.  Inverting is enabled for SBus, so normal serial hardware built into the processor can be used with SBus.

I recall hearing long ago that there are some RC receivers (or FC's?) out there that skip the inverting, but that is non-standard.  Maybe FC's do it to avoid the cost of the extra chip on the FC or maybe the FC was designed without considering SBus.  The FrSky's that I have are all inverted, which is to say that they are "standard SBus".  I have several FrSky Rx's connected to LP FC's with SBus and they work perfectly.

So the question is what anyone means when they say "inverted SBus".  Do they mean the correct, standard way that actually inverts the serial protocol or do they mean doubly inverted which equals uninverted?

I would google the receiver in question and read a review or two or watch some receiver <-> FC setup videos to try to answer that.

Since you have your fingers deep in the code, you should be able to find where that inverter gets enabled or not.  A lot is driven by data structures.  If I wanted to order an SBus receiver and didn't know it's inversion status, I would just get it and make a version of code for it if it differed from normal.

[trust]

Great! Sounds like Frsky is the way to go, since it works already. Any recommended sources? I assume they all are 8 channels or more? With serial its so easy to have as many channels as you want.
Thanks.

[TheOtherCliff]

I just picked up a quad nearby to check and it has a FrSky X8R in it (connected to FC with SBus).  Certainly the X6R would work and would have more than 6 channels available on SBus.  I would bet that any FrSky SBus receiver that you use would work fine.  Some small receivers don't even have the PWM connectors any more.