Should I expect a crash at some point?
Nervously I took the Spy 750 Y6 up for the first time in over 3 weeks (had a warm spell of 25F today).
In stab it flies great, then switching to poshold it seemed fine, but did the twitchy thing again for a few seconds here and there, then seemed to smooth out (subjective). I brought it down and hovered nearby where it stayed rock steady for a minute or so and landed.
So, what does it mean when INAVerr goes to 255 and stays there? From what I understand it is the FC not receiving data from the GPS properly. Apparently this copter has done it from day one since transplanting the PIxhawk and running on AC3.2 and 3.2.1, with the 3DR GPS and the current CSGShop Neo-M8N. These errors did not exist on the Y6B with 3.1.5 and the 3DR GPS.
Any help is appreciated.
Replies
@tshado,
The Inav errors mean that inertial nav has not received a GPS update within 0.3 seconds. So that probably means that the GPS is running too slowly (i.e 3hz or less) or messages are being missed. I've never used one of these GPSs so I'm really not sure what exact technical issue is that's causing the missed messages.
It's hard to say how badly this will effect inertial nav's position and velocity estimates but it will have a negative effect I think.
One of my post and Randy's answer about INAVERR was deleted (I asked why) on the thread
http://diydrones.com/forum/topics/gps-issues-do-i-need-a-gps-ground...
For all of you to be aware , please read below Randy's answering to the INAVERR problem and my following answers
So if you agree, as this Thread opened by DG is generic to INAVERR, perhaps we could continue here
Let me know, thx
Several threads here on DIYDrones and RCGroups have been opened to discuss about the explanation and what represent these INAVERR errors in performance monitoring in logs
This problem was reported end of January
Still no answers from 3DR/Dev guys, to tell us something about this INAVERR in logs
A ticket was opened in Github about that
I know that they are probably busy, but could be great if somebody could tell if this INAVERR error if indicating a problem or is not
I found a post from Randy who in last November was thinking INAVERR at 255 was not a "very good thing"
http://diydrones.com/xn/detail/705844:Comment:1482305
Marcus,
Thanks for the info. Your copter missed one GPS message and went 0.07seconds without a fresh GPS update (you can see the 400ms jump in the GPS time between lines 2593 and 2606). You were in Loiter mode but it was so short lived it didn't upset the navigation at all. If it was -rc6 you would have seen a very slight twitch. If that INAVErr was 255 meaning it had maxed out the recording of errors I'd be more concerned. For now, this is consistent with what I'm also seeing which is that we're getting occasional missed messages which we still need to get to the bottom of but in low numbers it's not dangerous.
MarkM,
That's interesting. A dedicated M8N thread was created. Copy your post over there if you wouldn't mind.
http://diydrones.com/forum/topics/gps-issues-do-i-need-a-gps-ground...
Compress it (or not) and upload to Dropbox, Google Drive, Mediafire etc. then share it. If you don't want to, no problem, but the more people bringing this to the dev's attention, the more likely it will be addressed. Either it is a problem or it is not. To me there's no middle ground here.
I can't speak for everyone, but having confidence in the software/firmware is most important. If there are conflicts with hardware, it needs to be figured out or at least acknowledged.
It's under PM (Power Management)
RE: Hans
I see what you're mean. It should be updating at 200ms (5hz) but is skipping a beat. All I want to know is if the value of 255 (however that is derived) can cause the copter to malfunction. And if it can, why. That's it in a nutshell. What does the value of 255 represent?
AKcopter,
If you post your log, I'd like to run it through Excel.
According to the following reference, Pixhawk recognizes the Neo-M8N and automatically sets the parameters. All the user needs to is reset the GPS to default first using U-Center.
http://www.rcgroups.com/forums/showthread.php?t=2353323
Here's the raw data in Excel for INVerr
Here is the data as seen in MP. It's missing the time values, but I wanted to get this posted while I remember.......going to try another quick flight before it gets dark.
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