Failsafe issue - X4RSB Sbus

ArduCopter Copter 3.6
1

Hi
Just about got everything ready for my first flight with Kakute F7 AIO, but I’ve got an annoying problem, I can’t seem to get the failsafe to work. Everything else is ok.

I’ve re-bound the receiver, reset the failsafe both as per FrSky instructions and this video https://www.youtube.com/watch?v=Da1kZUkdy_o

But when I turn off the radio, the values on MP remain as they were.

Anyone else had a similar issue?

Kakute F7 AIO, X4R-SB with Sbus & S.port, 9XRPro running ERsky9x, 'copter latest as of ~31st December

Edit - quick follow up, values don’t change on MP even if I unplug the receiver - so it appears to be a general sbus issue?

2

Is it possible for you to test the receiver w/ a servo, to see if it really holds signal or goes to no pulses?

I am using crossfire, but it is connected to my flight controller as SBUS (so, arducopter thinks it’s sbus)… it works. When I turn off the transmitter, a couple seconds later it failsafes.

3

Unfortunately I don’t have any sbus servos.
I guess I could get the oscilloscope out, never tried it on sbus.

However, it surely should failsafe if the receiver gets disconnected?

4

Ok, this is either me misunderstanding MP, or a bug!

I’ve checked the outputs from the receiver using a logic analyser, and although I don’t have sbus protocol decoded on the analyser it’s clearly dropping to zeroes when I turn off the Tx - however the MP display remains as-is.

Noob question I know, but how do I tell whether it’s a just problem with MP, or whether it will actually be a real issue on the copter?

5

I use a regular Pixhawk but can surmise this should work with your flight controller as well. Actually, after it’s bound, you don’t do what he. Instead, go to your Tx and set the Failsafe to No Pulse. This should make the Rx recognize no pulse when you turn off the Tx; consequently should be sensed by your FC and MP to recognize it’s in failsafe.

Good luck.

6

Thanks everyone, it’s now working fine - and possibly was all along, and I’ve been falling foul of a feature / bug of MP.

On the Failsafe page the values are remaining at the last value when I turn off the receiver, however if I go to the Flight Data page it’s showing ‘No RC receiver’ / failsafe.