Factory reset/bootloader reset failures

[jmlich]

Yesterday, I noticed some strange behavior from the Recorder app. It simply froze when I tried to start it. My guess is that it was trying to load several hours of recorded data from the previous session or something similar.

Today, I tried to update the apps using Chrome and https://banglejs.com/apps/. During the update, the watch froze. I was able to enter the recovery menu, but attempting to restore the factory image failed with an error message (see the attached photo). After the failed recovery attempt, the watch would no longer boot.

I then tried flashing the bootloader again. The error message from that attempt is shown in the next attached photo. After that, the watch started booting again, and I was able to install some apps.

Since then, I've noticed that the smartwatch has frozen a few more times. The clock on the watch face stops updating, and holding the button to force a reboot fixes the issue.

Just now, I reflashed the firmware over the air using https://banglejs.com/apps/?id=fwupdate. I haven't had a chance to see whether it fixes the issue yet. I'm wondering whether it's recommended to reflash it via USB instead. I'm not even sure whether USB flashing is possible on my device. Before all of this happened, I was running firmware version 2v29.

[gfwilliams]

Hi! 2v29 firmware is basically the latest and should be fine.

What you seem to be encountering is possibly an un-cleared area of flash memory on the watch (which could have been corruption caused a long time ago by a much older firmware). You might be hitting it now just because enough memory has been used.

I'd suggest doing a backup via https://banglejs.com/apps just in case, and then either go to settings->utils (or the recovery menu) and choose 'compact' - that will attempt to move everything earlier in flash memory and erase the rest, which might fix it. If that fails, you can try 'restore' via the app loader and give it the backed up data (which deletes all of flash and re-uploads all the files)

[jmlich]

Thanks! I've had the Bangle.js only since around February 2026, so I don't think it has ever run any really old firmware. If I remember correctly, it came with 2v28, and I updated it to 2v29, so I don't think the watch has ever had any ancient firmware installed.

I'll try the backup and the compact/restore steps and see if that helps.

[jmlich]

I tried to backup, reflash, restore, and compact the storage, but unfortunately it didn't help.

I am still experiencing OS freezes. A few times I noticed that the device did not turn off the backlight (for more than 5 minutes). Only a reboot helped. Sometimes I noticed the frozen state because the displayed time was already a few minutes behind. The RTC seems to be working correctly, since the clock is accurate again after reboot.

I am storing heart rate data every 10 minutes. The screenshot below and the database query show that this happened 8 times during the last 3 days:

sqlite3 ~/.local/share/harbour-amazfish/harbour-amazfish/amazfish.kexi "SELECT * FROM (SELECT timestamp_dt, heartrate, (timestamp - LAG(timestamp) OVER (ORDER BY timestamp)) AS lag_seconds FROM mi_band_activity WHERE heartrate > 0 AND timestamp > strftime('%s', 'now', '-3 days')) WHERE lag_seconds > 600 ORDER BY timestamp_dt;"
2026-07-05T14:40:00|81|4200
2026-07-05T18:30:00|114|2400
2026-07-06T13:00:00|110|7800
2026-07-06T21:30:00|74|1200
2026-07-07T13:20:00|83|3600
2026-07-07T14:40:00|103|4800
2026-07-07T16:40:00|101|1200
2026-07-07T18:20:00|85|1800

It looks like the freezes are causing gaps in the heart rate recording. Do you have any advice on how I could debug this issue further? The device isn’t sending any messages with information over UART (journalctl --user -u harbour-amazfish | grep handleRxJson). I have enabled logging and hope that I will get some useful information.

[gfwilliams]

Sorry - I was sure I'd responded to this last week. Actually 2v28 did have some issues with pairing data storage, but as long as you're using a normal firmware build (not the IFLASH or NOFLASH beta builds) that should be ok.

I tried to backup, reflash, restore, and compact the storage, but unfortunately it didn't help.

Did you get any error messages when you tried it? Particularly when doing the compact? And are you still seeing the FW addr errors?

It's possible that when there was the original flash write error, some of the apps code files got corrupted, and now even though it's ok, some of the code is broken. You could try Reinstall Apps in More... of the App Loader - this will just reinstall the apps code files, but should leave any settings you had alone.

I am storing heart rate data every 10 minutes.

What happens if you look at the health data via the floppy disk icon next to the health app on the app loader? https://banglejs.com/apps/?id=health

That will get the stored HRM data off of the Bangle, whereas I assume Amazfish only gets it when it's connected to the Bangle.

Otherwise I don't think a bunch of people actually use Amazfish, so I wouldn't totally rule out that it might be due to your connection to that. You could try disconnecting the Bangle from Amazfish and see if it still appears to misbehave?

[jmlich]

I reinstalled all the apps as well. I haven't seen the FW addr error since the first factory reset.

I also downloaded the health data via the web app:
Bangle.js Health 2026-7.ods
I highlighted the gaps in the data.

Amazfish synchronizes activity data by sending {"t":"actfetch", "ts": timestamp} and parsing the {"t":"act", ...} responses. I think the data in the ODS document looks the same. Additionally, the battery level indicates when the watch was charging.

I have now disabled Bluetooth on my phone, and I'll observe whether the watch still freezes without any interaction with Amazfish.

[enaon]

Sometimes I noticed the frozen state because the displayed time was already a few minutes behind. The RTC seems to be working correctly, since the clock is accurate again after reboot.

the Bangle does not have an RTC chip, so maybe Espruino was not really frozen, maybe an app is the problem.

[jmlich]

Thanks for hints. I can confirm, the Amazfish is causing freezing. I am working on fix.

[gfwilliams]

Great! Do you know what exactly is causing it yet? It's possible that it's requesting health data for a long time period when it connects, and it is that which is hanging the Bangle as it outputs a ton of previously-saved data?