Connection issues after flashing

[TFMvdBroek]

So I've flashed the v3.5 custom firmware for the Xiaomi Mijia thermometer. It all seemed to go fine.
After flashing no settings showed up, and the flashing software showed that alternative firmware was detected.

I decided to go back to original firmware, so I flashed the one for B1.4/B1.9. This also worked but now I can't connect anymore to flash the custom firmware once again.

I'm getting this error:
NotFoundError: No Services matching UUID 00010203-0405-0607-0809-0a0b0c0d1912 found in Device.

Display etc seem to work fine still.

[TFMvdBroek]

Noticed I have hardware B2.0, this might be the issue. Flashing from my phone seems to work tho.
After this new flash, flasher shows HW B1.7 ...

[TFMvdBroek]

Do you think I can flash others? I ordered 4, they all seem to be hardware B2.0.

[Xploder]

Mine, manufactured in 11/2021, are B2.0 aswell.
Can we help with info to get those flashed?

I'd like to get the firmware dumped. Can someone please point me to directions for that? I own a FTDI based UART adapter and I've ordered a CP2102 one aswell for delivery tomorrow.

[Xploder]

I was able to dump the flash of my device.
Imagine my disappointment when it checksummed to be the same as "Original_OTA_Xiaomi_LYWSD03MMC_v1.0.0_0130".
xiaomi_LYWSD03MMC_v1.0.0_0130_B2.0_orig.zip

It's the same for me with ATC3.5a. After flashing, it shows as B1.7

[pvvx]

It is necessary to find the differences, to determine the version 2.0 for this firmware.
I don't have version 2.0 and 1.7 yet.

[Xploder]

Stock Firmware is the same and your version 3.5a works well on B2.0.
If you need any hardware info about B2.0 I'm glad to help.

[backerman]

3.5 works fine on my B2.0 flashed from Edgium 98.0.1108.13 on Windows 11 build 22000.376, other than claiming it's now B1.7.

[abarbarich]

Confirming I have 2 x B2.0 flashed with 3.5 and Working well, however Device reports that it is B1.7

[OscarHanzely]

I cannot connect to the device that originally reported B2.0 and later reported B1.7 anymore. The 3.5c did not seem to work and now I have the exact same issue as the main poster. Sorry, I did't see that and opened new issue. It could be closed as a duplicate.

Basicaly after flashing with custom firmware the device could not be connected to. The device operates and still shows temperature on built in display.

[pvvx]

This will most likely help you:
#172 (comment)
Or use an Android smartphone. Android has the fewest bugs with BLE.
Windows is next. Linux is worse, iOS is even worse.

[mjsage]

I received a B2.0 version today, flashed it from android with the current version 3.8 and after that it kept disconnecting shortly after connection.

Connected just long enough to start it flashing back to original firmware, and uploading the firmware seemed to keep it connected until complete.

[nikito7]

Same here. Back to original and then 3.8 work

[mjsage]

I received a B2.0 version today, flashed it from android with the current version 3.8 and after that it kept disconnecting shortly after connection.

Connected just long enough to start it flashing back to original firmware, and uploading the firmware seemed to keep it connected until complete.

Meant to add that putting a brand new battery in did seem to give a very tiny bit longer before some disconnects, which helped to make it possible to start the flash back to oem firmware. The one I used originally had been briefly used to test something and was down to just over 3V.

With the oem firmware restored, a connection to telinkmiflasher still dropped once in a while, but after setting it up in the OEM app, the connection to telink seemed solid. Something in the stored config perhaps?

Also after flashing the 3.8 firmware on, the flasher identified the device as B1.9 instead of B2.0 it had previously.

[mjsage]

Same here. Back to original and then 3.8 work

In that case I might try again then and if it connects long enough to change anything, try changing the connect latency as well #11

and maybe add a cap.