Crazyflie Brushless stuck M2&M3 Leds on

[matejkarasek]

Hi,

My Crazyflie Brushless is stuck with the blue M2 and M3 leds on. No other lends are on/blinking.
I can put it into bootloader and update firmware via cfclient and Crazyradio (I have verified I am flashing the correct platform - cf21bl), but it remains stuck in this state, no matter what firmware version I upload. Upon st

This happened when I was installing a flowdeck, it may be I once connected it in a wrong orientation, which triggered this, but not sure...

Any ideas how to unbrick it are welcome...

Thanks,
Matej

[ArisMorgens]

Hello @matejkarasek!

This is odd. Attaching a Flow Deck in the wrong direction should not have this consequences on the platform. Could you narrow down the issue to see if it could be a faulty deck?
I would recommend flashing the firmware again without any deck attached, and testing with different Flow decks if you have others available. Please, keep us updated on the progress.

[matejkarasek]

Hi Aris,

thanks for your reply.
There are no decks connected to the brushless. I can put it into bootloader and update the firmware via cflient and Crazyradio without issues.
But when I power it up, the motors beep shortly (not the full startup sounds), both blue leads stay on, but nothing else happens (no red led blinking), it remains stuck in this state.

[matejkarasek]

So I noticed there is a similar issue reported with the Bolt 1.1, our Brushless behaves exactly like in the video posted there:
https://github.com/orgs/bitcraze/discussions/2058#discussioncomment-15074644

[matejkarasek]

Thanks for your answers!

I do not see an obvious short anywhere...

Assuming it is the broken EEPROM, is there a way to reflash it?
I found these cflib examples, but I cannot connect even via usb (uri usb://0)...
https://github.com/bitcraze/crazyflie-lib-python/tree/master/examples/memory

[matejkarasek]

There might be a short happening somewhere. If you study the blue M3 LED (STM32 power led) carefully for a while, do you notice it flickering at some point. That could we a short triggering a reboot.

If I power the Bolt from a battery, M3 remains solid. But if I connect it to the PC via the USB, M3 will sometimes flicker...

[tobbeanton]

I'm still trying to understand the issue and to me it looks like a hardware issue. The EEPROM is half broken somehow. If I replace it with a new one it starts to work, but at the same time it does respond when checking it with a I2C analyser. It is a issue that puzzles me...

[tobbeanton]

After more digging both a broken EEPROM (or missing) as well as a corrupt can cause this error. In this PR it should hopefully be fixed. Try it out and let me know the result.

[matejkarasek]

Hi Tobias, I confirm the PR worked, flashing the updated firmware fixed it and the brushless now boots up normally. So I suppose the EEPROM got corrupted somehow in my case.
Thanks for the quick fix!