+- XPS Technical Support Forum (https://www.xtremepowersystems.net/forum)
+-- Forum: XPS Products (https://www.xtremepowersystems.net/forum/forumdisplay.php?fid=1)
+--- Forum: X10+ (https://www.xtremepowersystems.net/forum/forumdisplay.php?fid=3)
+---- Forum: Setup and usage (https://www.xtremepowersystems.net/forum/forumdisplay.php?fid=9)
+---- Thread: X10 SBUS input gives steady flickering (/showthread.php?tid=53)
RE: X10 SBUS input gives steady flickering - flyingw - 06-16-2025
Ok, so the only combination I could get to work using SBUS to the X10+ is a Futaba S-FHSS transmitter talking to a Futaba receiver that is outputting SBUS to the X10+. I reckon a Futaba FASST transmitter/receiver would also work but I don't have that equipment.
It must follow that the Futaba transmitter and receiver respect the proper SBUS protocol, frame rate and timing, and consequently the X10+ remains happy talking SBUS. The Taranis on the other hand uses a frame rate for its XJT-D16 output to the XPS-J1 module that is not SBUS compatible. Also, when the Taranis outputs PPM to the XPS-J1 module it uses a 22.5ms frame rate and that also results in a non-standard SBUS frame rate at the X10+, making it blink.
For years I used a Taranis talking SBUS directly to a DragonLink transmitter module which in turn talked to a DragonLink receiver. The DragonLink receiver output SBUS to a Pixhawk flight controller. It is possible that with the Taranis talking SBUS (not XJT-D16) directly to the DragonLink transmitter module, the SBUS protocol was correct and intact by the time it went out of the DragonLink receiver and into the Pixhawk. (I could not find any place in ArduPlane that logs errors on the SBUS connection into the Pixhawk - there may have been some but the servos worked without notchiness even in manual flight mode and I flew successfully with the system.)
In conclusion:
- I will use Xtreme protocol for XPS Nano and RFU receivers to talk to the X10+
- I could also use a Futaba transmitter and Futaba receiver that outputs SBUS to an X10+ as well
- I cannot use the Taranis and XPS-J1 transmitter module in a setup that requires an SBUS output out of a Nano or RFU
RE: X10 SBUS input gives steady flickering - XPS - 06-16-2025
"- I cannot use the Taranis and XPS-J1 transmitter module in a setup that requires an SBUS output out of a Nano or RFU "
Correct - it works, but frames are dropped, so it should not be used. This is the fault of the Taranis itself as it doesn't output the correct frame rate for the SBUS protocol.
RE: X10 SBUS input gives steady flickering - flyingw - 06-16-2025
Stated another way: The Taranis communicates with the XPS-J1 transmitter module using either PPM or XJT-D16, and neither of these protocols use a frame rate suitable for SBUS.
RE: X10 SBUS input gives steady flickering - XPS - 06-17-2025
Yes!
RE: X10 SBUS input gives steady flickering - flyingw - 08-13-2025
Jim,
The only way to talk to an RFU is with an XPS transmitter module. An XPS transmitter module can only use PPM or XJT-D16 to talk to a transmitter body.
Neither PPM nor XJT-D16 use frame rates compatible with SBUS's 14ms.
How did you test your RFUs with their output set to SBUS into an X10+?
Thanks,
Paul
RE: X10 SBUS input gives steady flickering - XPS - 08-13-2025
With transmitters that output the proper frame rate that is required for the SBUS protocol. You can adjust frame rates with JETI, Multiplex, and other brands.
RE: X10 SBUS input gives steady flickering - flyingw - 08-14-2025
Ok, that helps me.
Armed with this new idea (for me) I set up a model in the Taranis using PPM with 4 channels and a 14ms frame rate (4ch x 2.2ms + 4.7ms). I configured the RFU and the X10+v2 to communicate using SBUS. It worked! The RFU bound to the XPS transmitter module and the X10+v2 had a solid green light, and servos plugged into channels 1 through 4 on the X10+v2 operated smoothly.
Then I tried the same PPM 4-channel and 14ms configuration in the Taranis with a DragonLink transmitter module. The SBUS output from the DragonLink receiver to the X10+v2 seemed to work a little better this time as the X10's green led was showing random less frequent single blinks about twice per second - not a steady 10x per second blinking like when I fed the DragonLink transmitter module directly from the Taranis with SBUS. The servos worked relatively smoothly, but there was still some notchiness and I think that some control data was being lost.
So thanks to your advice I got the RFU to pass good SBUS on to the X10+v2 (and presumably other devices) provided the XPS transmitter module is fed with an appropriate frame rate.
With DragonLink I tried multiple settings including SBUS and PPM and varying the number of channels but I could not get it to deliver a good SBUS signal to the X10+v2. DragonLink is no longer supported so I'll probably never know how to work with their SBUS implementation.
RE: X10 SBUS input gives steady flickering - XPS - 08-14-2025
A lot of these 433MHz radios do not have consistent frame rates.
RE: X10 SBUS input gives steady flickering - flyingw - 08-24-2025
(08-14-2025, 01:23 PM)XPS Wrote: A lot of these 433MHz radios do not have consistent frame rates.
Out of curiosity, I ordered this $14 generic SBUS to PWM converter device from Amazon. In the photo below it is to the right of the X10+v2.
I used a Futaba S-FHSS transmitter signal to talk to a Futaba R2000SBM (SBUS) receiver, which in turn acted as relay to output SBUS to a DragonLink transmitter module.
On the receiver end a DragonLink Nano Rx output SBUS to the generic SBUS-PWM converter. Interestingly, both analog and digital servos worked smoothly, without notchiness.
Now I'm confused. This $14 device appears to be happy with the DragonLink SBUS signal where the X10 is not happy with it. (God only knows what is going on in the device.) I do not trust it to fly, but I will set it up in a car for ground testing. I haven't tested failsafe yet.
I believe that DragonLink uses 12 channels - maybe that's something that the X10 sees as it expects 16 channels, consistent with the SBUS standard. Maybe this device ignores that?
RE: X10 SBUS input gives steady flickering - XPS - 09-04-2025
Sure, the same thing could be done with the X10+ if you make the output frame rate what SBUS needs no matter what the input is, but this requires skipping frames because the frames are not synchronized, resulting in losing frame data which adds latency.
Futaba SBUS is always 18 channels of data. 16 channels of proportional control and two switch states.
Take a look at the PWM outputs on a scope, especially channel to channel and also referenced to the input signal.
The X10+ requires the SBUS protocol to be used as specified by Futaba. Anything else should technically not work at all. I should probably change the X10+ coding so that when a non-standard SBUS signal comes in (wrong frame rate) that it doesn't allow it to work at all.