BL602 goes offline randomly

[CommanderRedYT]

Describe the bug
I have had this happen a couple of times. My BL602-powered LED Controller randomly disconnects from the wifi (when I connect it in the Cube IDE there are plenty of wifi deauth errors) and never comes online again. Also, it fails to open a hotspot.

The only solution I ever found was to reflash the firmware. Somehow, that always worked. (Power cycling never worked)

Firmware:

• Version: Happened to all versions I tried released in past ~2 years
• Device?
• Chip/model: BL602
• Device config?

To Reproduce
Steps to reproduce the behavior:

1. Install the firmware
2. Wait between couple days and multiple months (very random)
3. The device will disconnect forever during the night when you are in your bed and nothing with the wifi happens

Additional context
What confuses me is that it does not even try to open a hotspot. Also, tried it with my wifi being in WPA2 only, WPA2+3, turning off 5GHz with same ssid etc., but nothing ever helped. Basically at this point I have soldered on some pins so I can easily plug in my flasher and reflash it when needed...

[openshwprojects]

Hey, is it with MQTT connection on or without it?

But come to think about it... I haven't seen a crash that required a reflash yet. Maybe you would be able to take a flash capture (read) before and after the crash? So we can tell what's corrupt?

[CommanderRedYT]

I have enabled MQTT and it should be connected to my MQTT server. But it also vanishes from the network (cannot access its webpage anymore).

I can try taking a flash capture when it occurs again, but this could be weeks or months in the future. It is very unpredictable when it happens, only that it happens when I actually need it to work.

[jekader]

Just to discard the option of connection issues due to interference: is it just as unstable if you place it like 1m from the router? I've got my bl602 disconnecting a few time per day as it's far from the router but it reboots on watchdog and then is able to access MQTT.

[CommanderRedYT]

Right now it is basically directly under a unifi u6+, before that it was directly to a devolo magic home adapter. So basically should always have perfect connectivity.

[jekader]

Hmm, interesting. I've been using bl602 with mqtt for almost 2 years on openbeken and never had similar symptoms especially since re-flashing fixes it for you.

Next time before you do so - as recommended, please do a full flash dump (even better - take a flash dump now while it works, then compare with the broken version) and also try grabbing the logs of the board in the failed state as they might also reveal something.

As the flash contents seemingly get corrupted, there's something changing them: the firmware image, solar flares flipping bits or just a defective flash on the device, who knows... A flash dump could reveal the pattern hopefully and help identify the reason.

[CommanderRedYT]

As far as I can remember, the logs look just like when it's not broken. It just throws wifi errors. But then again, I do not get why reflashing instantly helps, but power-cycling with even a long off time of multiple minutes does not help.