GPS and compass error to be ignored when flying manual

[YO3HCM]

Current Behavior

Dear iNAV team,

I fly my RC plane using RadioMaster nexus-xr in mode manual or angle . I use GPS to see speed mainly and home arrow, and compas just to not get lost, not fancy autonomous navigation for me.

Unfortunately the nexus-xr connectors are not very reliable and during flight the GPS and compas periodically disconnects and reconnects.

The problem is no matter how I set the iNAV the controls disarms midflight and the plane crashes

Desired Behavior

I want to have GPS and compas just for indication purposes even f is unreliable, without disabling my controls

Suggested Solution

ignore HWFLG errors in manual or angle mode.

Who does this impact? Who is this for?

majority of RC Flyers that want to break personal speed records

Additional context

searching the plan in the big corn field is exhausting, not even the beeps works

[Jetrell]

The problem is no matter how I set the iNAV the controls disarms midflight and the plane crashes

@YO3HCM When you say it disarms. Do you mean it can't be rearmed. Because that should be possible. Or do you mean the FC locks-up ?
Do you have a flight log. That would help work out if it is a connector issue, or something else.

When connected. The GPS and Mag aid the attitude and heading reference system.

[YO3HCM]

Hi Jetrell,

Sometimes, the connection to the gps/compass is reestablish mid flight, and the fc arms back automatically. But is random, i could put glue and do some hw rework but on nexus xr is very hard.
I tried to download the black box but after 4h of very slow download i quit.

The behaviour was reproduced home, when on purpose disconnected the GPS/compass. The servo and esc go to a default position, even in Manual mode and rc controls are ignored.

If i disable the GPS/compass everything is ok. But i want to avoid this.

It would be a great feature the option to keep heading computation and servo/esc outpot. Independent for basic modes.

Thank you

[breadoven]

It's not really clear what's happening here. INAV won't disarm because the GPS drops out. Sounds more like a Failsafe which indicates the RC link is being lost. Assuming there is no Failsafe then the controls locking up would indicate a basic Emergency landing, i.e. controls go to fixed positions and the motor cuts out. However, this would only happen if you were using a Nav mode. A log would be most useful. Use Blackbox(MSC) mode from Configurator CLI page to access the log file, it's much faster to download.

[YO3HCM]

I hope it helps: https://www.dropbox.com/scl/fi/32atghjq7hymmzjxxwlug/inav_all.bbl?rlkey=aiav2t82mi1kou47jey2o75ru&st=907m0syx&dl=0

[breadoven]

Looking at the log, e.g. the last log in the log file, it appears the plane is performing an emergency landing due to receiver failsafe. It doesn't disarm and the GPS seems to lose lock sometimes but that doesn't affect anything since Nav modes aren't being used.

You'd be better off changing the Failsafe procedure from land to RTH if you want to avoid crashing which is what will happen with a fixed wing if you do an emergency landing on anything other than a large flat area.

The log shows the receiver type as XB-B-RJ01. Shouldn't the Nexus-XR be using ELRS CRSF ?

[YO3HCM]

First I want to thank you for helping me solve this out.

I flash my nexus-xr from iNAV 9.1.0 but in "firmware flasher" the only board options were: "Nexus" and "Nexusx" , I used the second.
In configuration, the receiver is set on CRSF, and on ground test is working well. I use Radiomaster TX12 , and ELRS 3.6.3 on both TX and RX, I am not a fan on latest versions...

What can cause a receiver failsafe ?

Also how can you see all those details out of the log files ?

I use "INAV Blackbox explorer" and I see only few details

Thank you

[breadoven]

You can get a table of all available log parameters using the View -> Values Table dropdown at the top left of the Blackbox explorer screen (or press keyboard T). I have GPS data available in my version of Blackbox explorer but it's not included in the last available version 7.0.1 (iNavFlight/blackbox-log-viewer#102 never made it into that version). You'd need to use https://github.com/iNavFlight/blackbox-tools instead to see the GPS data.

Also better to use a lower logging rate unless you really need a high rate, the lowest rate is fine for general logging on a fixed wing. Makes the log files smaller.

Not sure about the receiver failsafe. It does seem to coincide with the GPS losing lock so it's something to do with that. It goes from many sats to 0 instantly and the GPS is flagged as unavailable. I take it this is because of a poor connection. This might be affecting the receiver in some way if that's the case. Solution is to fix the GPS connection.

[sensei-hacker]

If you're losing receiver signal and GPS at the same time, you may be flying through a strong RF signal. Look around the area for towers.

In particular, a strategic early warning radar a kilometer away will blow them both out completely. (And you'll piss off the folks running the radar, if you weren't supposed to be flying there). Didn't ask me how I know.