M2 and M3 Flashing blue with a solid light.

[noahra]

I have worked with my CF-drone for quite a while. Each time I plug in a battery, the rotors spin one after another as a short sound sequence chimes. But today, suddenly, that stopped happening. Instead M2 and M3 are lit up with a solid blue color and I can't connect to it with cfclient anymore. I tried disconnecting the battery etc but that didn't do anything. Anyway, then I held the power button for a couple of seconds and now M2 and M3 are instead blinking (bootloader mode). But I still cannot connect to it via cfclient: see the image:

[knmcguire]

that is indeed weird! But it seems that it still can go into bootloader mode so that is good.

Could you try a coldboot recovery flashing? You can check the instructions here: https://www.bitcraze.io/documentation/repository/crazyflie-clients-python/master/userguides/recovery-mode/

[tobbeanton]

No, not easily when the system doesn't boot but e.g. connecting a debugger it can be checked. Have you tried the cold-boot recovery?

[Guitarwang01]

yes, I tried to flash the latest release for several times. At the same time, I also read the discussion: https://github.com/orgs/bitcraze/discussions/172 and tried DFU update but it remains not working.
The drone is able to connect to the client through crazyradio, and there is no heat generated while connecting to the battery, so I think probably it is no a hardware problem. But I also followed the tutorial of DFU and the responce in terminal seems normal. It is very strange.

[Guitarwang01]

By the way, i also want to describe the performance of LEDs:
M2 and M3 lid solid light when the problem occured;
after I tried cold-boot recovery, M3 was out and only M2 lid a soild light;
after I tried the DFU update, M3 was back.
At the same time, M4 performs well whenever the crazyflie connects to the crazyradio, and M1 is always out.

[tobbeanton]

You say it can connect to the cfclient. Can you post the console tab output after connecting to it? Does e.g. the propeller test in the console tab work? What is it that doesn't work? Could it be that the M1 led is broken?

[Guitarwang01]

Oh, I'm sorry that I didn't express that correctly. It cannot connect to client under flight control site, it can only connect to bootloader when the drone is under bootloader mode. The output of client stays on "connecting to radio://0/80/2M ..." and "found 0 devices". The nomal propeller test doesn't work when I turn it on. So I think maybe the drone initializing program didn't run properly.

[knmcguire]

Alright let's start again as it is a bit unclear to us what is going wrong.

• So M2 and M3 were solid when you first started. M2 and M3 being solid is normal for a crazyflie but I assume M1 was not flashing at that point. And no cfclient connection
• Cold boot didn't work. M3 was off which means that the stm flash failed.
• With the DFU update, M3 is back

M2 stands for the NRF chip so if you don't reflash that nothing will happen there.
M3 stands for the STM, which holds the crazyflie firmware + bootloader (that enables over air flashing), so if that is off or not responding, there is something wrong there.

So when you say that you did a DFU update, did you update the firmware or the bootloader. There are some very important differences between the two and if you have flashed the stm firmware over the bootloader that will break everything.

[tobbeanton]

M2 and M3 both blink right and the loading bar of flashing firmware is normal.

So flashing over the radio does work? I don't see why a cold boot flash would not work then.

[Guitarwang01]

I want to make sure that does flashing over radio means the same as cold boot flash? I've tried several times and it doen't work.

[knmcguire]

Flashing over radio is a bit broad: Either a warm boot (where you are already connect to the cfclient and initate flash without pressing the button for a long time) or a cold boot (where you manually put the crazyflie in bootloader mode with a long press). Over air flashing just means that you are not using a cable or programmer to flash the crazyflie, only the crazyradio.

But sorry, my wording was different that might have confused @tobbeanton. @Guitarwang01 are able to do over air flashing with cold boot, but the firmware side of the stm is still not responding as it should upon restart. probably freezes due to an unknown reason.

[Guitarwang01]

There is a good news that another teammate tried flashing a previous edition flamware on his PC and it worked again! We also tried several editions and found only some of them works. The latest edition also doesn't work. That seems very strange. We are also not sure which section goes wrong duing our operation. But whatever, it works now! Thank you for your very patient explaination!

[knmcguire]

Ah no worries! and happy you found it!

But that it happened with the latest firmware is a bit worrysome.. we are just in the process of release testing.... perhaps you just had one that happened to be faulty? Could you check perhaps the commit hash (like with git log)?

[Guitarwang01]

Sorry for my late reply. We tried flash the zip from release instead of from a downloaded file, and I am not sure how to check the hash. Can you tell me something about that?

[knmcguire]

ahhh oke, no the commit hash is just if you build and flash from the github source repository. Which version of the release zip file did you use that worked out?

[Guitarwang01]

We tried many versions and I can't remember precisely. I'm sure that firmware-cf2-2023.7 doesn't work well all the time. I remember we tried this version at very first when we just start this project and it worked very well until the problem occured. We finally flashed the first version firmware-cf2-2019.02.1 and it was back again. And my teammate is sure that the versions of 2019, 2020 and 2021 works well.