Beta 12 IMU Faults

[aj-foster]

I recently encountered an issue related to IMU faults that doesn't align with my reading of the changelog.

Here's the update path we took on Systemcore:

• Beta 11: first update we applied, via LHM (full flash), no issues
• Beta 12 prerelease (sorry, I can't remember which prerelease build it was): second update, via LHM (full flash), no issues
• Beta 12 final release: OTA llupdate, introduced IMU faults for the first time
• Beta 12 final release: reinstalled via LHM (full flash), resolved IMU faults

At each step, I did confirm that the update persisted (A/B swapped and had the right version).

By IMU faults, I mean that the IMU fault counter ticked up on every read, and no data was available on the dashboard. Reboots did not solve the issue. This sounds like what was mentioned in the changelog for Beta 12, but as you can see, my experiences didn't match up with the expected version numbers.

Wanted to bring this up in case somehow the method of installation brought different results. Always possible it's a red herring; I have not attempted to flash backwards and replicate it.

tl;dr suspicious that OTA update somehow caused IMU faults when equivalent full flash was fine.

[bhjelstrom]

Hi @aj-foster, given some of the intermediate fw changes throughout the beta 12 releases, there's a situation that would have required a power cycle after updating the OS. Did you try power cycling before doing the full reinstall? We add something to address this sort of thing if it is ever necessary in the future.

I guess the key question for me is: were the "reboots" mentioned software reboots or full power cycles?

Edit: Is there any chance that an incorrect llupdate was applied when doing the prerelease-final release OTA? We check for Systemcore vs limelight models, but we don't check for Systemcore alpha vs Systemcore beta

[aj-foster]

Hi there,

Yes, I did a complete power cycle after each upgrade step (and another to confirm the IMU faults were persistent). Not sure what the recommended cooldown period is, but I kept it off for about 10 seconds.