Pixhawks and S-Bus (Futaba R7008SB) Connections

It’s my understanding that Pixhawks with APM 3.12 and beyond supports the S-Bus protocol.

  1. Do you just plug the S-bus output right into the RC-in connector of the Pixhawk?

and here’s the bigger question…

  1. I have several Pixhawks that are using R7008SB’s and PPM encoders. I’m in no burning rush to eliminate the PPM encoders, as they work fine right now. But they do represent a future point of failure, so at some point it makes sense to take them out.

Is everything nailed-down with the S-Bus and Pixhawk? Is everything settled or should I wait a few more revisions? This isn’t a time-sensitive issue, but at some point I’d like to make the switchover – just not before everything is settled-down.

  1. Yes, right into the RC pins; it sorts out whether it is PPM or s-bus signal
  2. I have had complete success with s-bus receivers being plugged straight in with a 6208SB receiver. I have never seen anything strange with RCin in all my flashlogs.

I would also like to see others results before I strap mine to a much larger, more expensive unit.

Thank you. That’s where I stand right now.

It makes sense to eliminate another potential point of failure, but I don’t want to be an alpha tester for new S-Bus code. I may wait till 3.2 releases, then remove my PPM encoders.

I tried it with a tabletop Pixhawk setup (the one I use for testing code) and it appeared to work just fine off the latest GitHub sync.

And here’s a little twist… I synced my R7008SB with all 18 channels. I wonder if it’s placing all 18 channels on the S-Bus. Sounds like something I should look for in the source.

My PX4 doesn’t reconize the sbus2 signal coming out from my R7008SB, and neither the sbus1 signal coming out from channel 8 pin in mode B or D. Only the sbus1 from my R6208SB works.

I guess it’s just the issue with PX4?

[quote=“gsenroc”]My PX4 doesn’t reconize the sbus2 signal coming out from my R7008SB, and neither the sbus1 signal coming out from channel 8 pin in mode B or D. Only the sbus1 from my R6208SB works.

I guess it’s just the issue with PX4?[/quote]

It would make sense that the SBUS2 signal doesn’t work – I believe SBUS2 is a different protocol (but I could be wrong).

Out of curiosity, I tried to put my R7008SB in Mode D just to see what it would do, and it didn’t work.

I can’t imagine why mode B didn’t work though.

[quote=“bcdebusk”]
It would make sense that the SBUS2 signal doesn’t work – I believe SBUS2 is a different protocol (but I could be wrong). [/quote]

You are correct sir, the Pixhawk currently does not accept S.Bus2 signals since they are in a different protocol that the code does not accept.
Sorry for that.

Hi there,

I am also trying to get 14 SBUS channels on pixhawk through the 6208SB. HAs anyone got this to work right?

Thanks