Failed when using TLSR825x USB-COM Flash Writer v0.4 to flashing TS0201_TZ3000_xr3htd96

[x-magic]

I'm trying to convert my Zigbee TS0201_TZ3000_xr3htd96 into BLE with CFW.

First I tried to do Zigbee OTA with info from #529 however can't make Z2M to OTA the firmware. So instead I decided to flash the device with UART instead. Here's my wiring:

(wired based on this and this)

Then I used the USB-COM flasher (460800, 3sec, with a CH343 UART), erased all flash, then flashed TS0201_v48.bin from pvvx/ATC_MiThermometer but no luck (after soft reset MCU, the LED no longer lights up even when button is pushed or replacing battery). Can't find the device in either Zigbee nor BLE.

Also tried to flash TS0201_v47.bin from pvvx/BLE_THSensor, same thing.

Finally tried to erase and flash the FullFlashbin from pvvx.github.io/TS0201_TZ3000, the device won't restore back to Zigbee mode. Still no LED on battery replacement nor button push.

Basically at this stage it's bricked.

Am I missing any steps? Any way I can be sure the firmware is properly flashed? Any suggestion is appreciated!

(Doesn't really matter for this one thermometer - I'm experimenting on it. Just that I have two more that I actually need them to be on BLE mode as Tuya Zigbee firmware's refresh rate is super slow, like 30 minutes per refresh mostly, while my LYWSD03MMC are refreshing at 30s or quicker)

Thank you!

[pvvx]

Connect UART RTS to the RST pin of the ZTU module.

[x-magic]

Connect UART RTS to the RST pin of the ZTU module

Yes, that's how I connected mine. RST on ZTU to RTS on UART. Also using the latest WCH driver for the UART (as there's a known RTS/DTS issue on default CDC driver.

Is it normal that pin B7/B1 (UART RX/TX) produces no output when booting? My issue is that I can't tell if the flashing is successful or not. All I know is that before I flash the firmware through SWS, Soft Reset MCU works and it toggles the device and the LED indicator flashes when booting or when button is pushed. Now I can't tell if the device is booting or not, as the LED or button are not responsive.

Thank you

[pvvx]

There is a simple version of the programmer with reading:
https://github.com/pvvx/TlsrComSwireWriter - TLSR825xComFlasher.py