Failsafe or RC problem?

Hello there

I’m new here ,build a copy of TBS disco pro. And went out for testing - despite some twitching I have no problem ( somethink like 1.5 hour in air ? ) Then I updated to 3.2

Flew around for few minutes … then suddenly copter felt down like a rock from 30m ! Happily to the soft ground - only one leg broken and maybe battery got some mark.

So I cleaned the dirt and spun the motors for the test - all ok. Than opened the logs.

What I see - (Curr and Voltage not shown , but battery was on 40% and Voltage around 14V under 25A load)
As I was in stabilize mode - RC was lost , failsafe kicked in RTL but throttle went to 0 ??
ERR message said BARO-0 error after that and imediately recovered (response to quick fall ? Because barro shouldnt matter in stabilize and even in RTL it should not turn motors of)

After that I went out and try another run, just few meters above the ground. Tried RTL from LOTIER mode - quad started to climb to desired 20m for RTL. Then I turned off my radio - exact same response. No problem here. After a minute or two same happen just two meters from me - felt down like a rock. Logs exactly same -RTL engaged - ThrIN drop to 0 , ThrOut follow.

Can someone give me an advice ?

Please provide tlogs and/or data flash logs to help troubleshoot your issue.

Sure , here it is. Thank you for your reply !

Sorry about that - I’v attached a picture to my first post but its not there ,So it should be here

Few more tests with OrangeRX lrs - previous was Radiolink AT9 - same issues. I’ll check the wirring ,and will try set up failsafe throttle to non-zero (hover maybe ? ) value - but still, shouldn’t be RTL ignore the throttle input and just fly home ?

Any hint please ? … I’m out of options …

Ok, I’m definitely lost - disabled radio switch to RTL when signal lost and changed to loiter mode, No crash since this.

GPS fix was ok everytime. No glitch detected. RTL tested (TX switched off while in loiter) and works.

I suspect this is a problem with your Radio Failsafe setup, but I am having trouble understanding your descriptions. It’s slightly confusing.

How exactly is your Rx setup to handle failsafe?

I see that FS_THR_ENABLE is set to zero, so you are not using the actual radio failsafe in Arducopter.

Hello ! Thanks for response !
True, I don’t have throttle failsafe set because I can’t set my throttle output lower than actual output of “zero throttle” is - only higher. (to explain : my RX THR output will drop to ~975 which is same as zero throttle - my RX/TX have F/S settings in TX - I can set output of each channel for the signal lost event based on actual HW output)
My actual setup is - All positions to neutral , only mode channel is se to match RTL mode.
(Maybe I’ll try to set my FS THR output by some changes in THR graph and then recalibrating my RC input)

In that case - Should I set FS throttle on my RX/TX to be 50% ? (At least it should not fall from sky :wink: )

Are you sure you can’t get the Throttle Endpoint in your Tx to go below 975? Have you played with the endpoint setting?

So , just to close this case - it was user fault (expected - too hurry , no RTFM ) - throttle failsafe is set and working. Previous problem was caused by bad failsafe settings and misunderstanding to RTL funcionality.