SBUS Output jitter

ArduPlane Plane 3.3
1

After upgrading to Plane 3.3, I enabled SBUS Output and tested on my wing (I use the frsky sbus to servo adaptors), and noticed a lot of servo jitter and uncommanded movement (My ESC’s even armed at one point)

Previous I was using a futaba pwm to sbus adaptor to generate the servo sbus signal without issue. Can anyone else confirm this? On the Frsky adaptors they have leds to indicate signal. The Pixhawk signal seems to have a slower refresh (??). I currently dont have access to a decent enough scope to get shots of the signals, but in looking at the logs there are no commanded movements from any rc_Out channels…

SBUS Input from the frsky x4r is great, no issues on input side…

2

Per Tridge on AP 3.3 release comments, check Telemetry for Rf interference.

I remove the RFD Modem and the jitter still exists. (The modem cables were still attached, but the modem itself was removed)…

I should be able to make a scope capture of the pixhawk VS futaba VS frsky direct sometime tomorrow…

3

checking out the sbus signal from the pixhawk vs the futaba adaptor. The signal from the pixhawk has about half the refresh of the futaba one.

For now I’m going to continue using the futaba adaptor attached to the pwm outputs on the pixhawk.