Correct OmnibusNanov6 build

[andyp1per]

This adds the OmnibusNanov6 HAL subtype to the list of boards to avoid compilation warnings

[andyp1per]

Need @1wick to confirm that the DMA change is necessary

[1wick]

I got busy w/ work, and tomorrow am home alone w/ my 4 year old, so probably won't be able to do any testing.. Maybe Sunday.
I have had several flights using the ESC Telemetry based notch w/ the official 4.0rc2 release, and have had no problems at all. So w/ this release, the noDMA mod doesn't seem necessary.

But, I'll put your firmware w/ the FFT back on it and do the same things I was doing a few days ago to see if I get all those prearm errors again. And then either way, I'll put the noDMA version on it and take a few flights and report back.

[1wick]

OK,
The issue is repeatable w/ even the default 4.0rc2. And even on a new FC w/ nothing installed, fresh of the bag.

Calibrate level, and I get 0x8000 error and cannot arm. 3.6 doesn't cause the error.
The no DMA version made no difference.

Doing a 'soft reboot' doesn't fix it.. that's when I start getting the 0x4000 errors as well. (by soft reboot I mean in MP, Actions, preflight_reboot_shutdown, DO Action)

It's ok after a complete power off.

[tridge]

the cal level error is easily fixed, and I've opened a PR for it here: #13043
The one I'd really like to reproduce is the SPI timeout. My omnibusnanov6 has now arrived but I don't see the SPI timeout. If anyone can give me exact instructions for reproducing that from a bare board it would be appreciated

[andyp1per]

@tridge I've not been able to reproduce. I guess we can see if the cal level fix makes the other one go away?

[tridge]

@andyp1per they should be unrelated. I'd really like to find the SPI issue ...

[1wick]

@tridge, For me, I got the SPI timeout if I hot reboot after doing a level calibration. That's the only time I got it.
So, calibrate level. It causes error. I thought a quick reboot would fix it, so I tried rebooting from in MP, actions, preflight_reboot_shutdown, then I got the SPI error.

[andyp1per]

@tridge, this simply adds the board id now so is completely safe

[peterbarker]

Closes #13678

[tridge]

please instead remove this line:
https://github.com/peterbarker/ardupilot/blob/master/libraries/AP_HAL_ChibiOS/hwdef/OmnibusNanoV6/hwdef.dat#L99

[andyp1per]

@tridge @peterbarker done.