This was a simple tuning flight in the yard.
I've had this quad trigger failsafes in the past, but I chalked it up to poor antenna mounting. This time it is mounted well (I think), it was only about 10 ft away about head high when the issue happened.
It was an uncommanded yaw for about a second (top circle in graph). I brought it down immeadiatly after.
Reviewing the logs i show throttle hit the failsafe value immeadiatly after the uncommanded input. It never trigger the failsafe (Maybe it was too brief).
Could this be anything but a bad Rx or Tx? See pics for how antenna is mounted. It is an FrSky X8R with Taranis+ transmitter.
log attached.
My current plan is to just replace the Rx, but I'm a little new so i wanted to post in case I'm missing something
Y shape is antenna. Rx is mounted on the lower plate under the pixhawk.
Replies
06/01/1980 - 000598: Mode Changed to Stabilize
06/01/1980 - 000598: Mode Initialised at 0 0 Alt: 0 Spd:0
26/06/2016 03:59:49 - 000617: Take Off
26/06/2016 03:59:49 - 000617: Mode Time Changed to 26/06/2016 03:59:49
26/06/2016 03:59:50 - 000721: Simple Mode is Disabled
26/06/2016 03:59:50 - 000721: APM Information: RC Pre-Arm checks have been completed.
26/06/2016 03:59:50 - 000721: APM Information: All Pre-Arm checks have been completed.
26/06/2016 03:59:50 - 000721: APM Information: USB is NOT Connected.
26/06/2016 03:59:50 - 000721: APM Information: System Time has been set from the GPS.
26/06/2016 03:59:50 - 000721: APM Information: Home is NOT Set
26/06/2016 03:59:52 - 001016: Super Simple Mode is On
26/06/2016 03:59:52 - 001016: APM Information: Home is Locked
26/06/2016 03:59:53 - 001315: Auto Mode is waiting for Throttle.
26/06/2016 04:00:42 - 015711: SET_HOME
26/06/2016 04:01:23 - 027700: LAND_COMPLETE_MAYBE
26/06/2016 04:01:24 - 027936: Landed
Odd that it shows Super Simple Mode on in the logs.
I'll talk with Kev to see if this is a problem with the Log Analyser app.
It's an issue with the app as I just checked my last log on my T960 and I have never enabled super simple and it also shows it enabled.
I would do a range test before doing anything else. Also check for nicks or cracks in the paddle antenna wires.
Your TX has a range test feature. I'd suggest using it.
Also check that your not getting any brownouts to your RX. Check the servo cable for any lose connections.
I almost always add at least a 1000uf 16v cap to my RX's [plugged into any open +/- leads on the RX] to help avoid any spikes or brownouts.
Logs don't show any real bad issues on a cursory look see. But I'd turn off super simple mode until you get everything worked out.
I too thought brownout, Craig I do the same trick with cap, but also add a low junction voltage shottky diode to free the rx and cap from getting pulled down by the load, effectively decoupling it. Interference is always possible in the pea soup 2.4g band, a leaky microwave or any of the myriad sources of interference available there, FHSS, or any frequency agile system is still fallible. I've had lots of strange things happen with most of my RC gear, including the hard discovery of a ground link beam traversing the far end of my property at around 250 feet, it is a death trap with my 2.4 gear, instant loss of control, not always with failsafe, I have had maxed throttle, loss of some functions and not others, and total failsafe, I now mainly use dragonlink, or with the 2.4 aircraft, never fly where I know it to be, after locating the towers.
Range test checks out fine and I've flown it over .5 km away. Range definitely isn't the issue. I've remounted the receiver since the first fail safe so I don't think it's loose wires.
Logs show the pixhawk voltage steady and I was just in a hover when the issue happened.
I've never used simple or super simple mode.
I've replaced the receiver and I think I'm going to enable telemetry logging on the Taranis in case the issue happens again, but i'm really hoping the Rx was the problem