[ SOLVED ] - 5$ fix to WYZE sense sensors dropping MAC address when battery level drops

Hardware
1

I used a generic CP2102-based USB to serial adapter from eBay. Any 3.3v-level serial/UART adapter/device should be OK.

Connect GND from the serial adapter.

Short the RX pad on the sensor to GND. This triggers the bootloader.

Connect 3.3v from the serial adapter.

Remove the RX pad to GND short.

LED should be solid red. If it isn’t, then this method will not work.

Connect the TX/RX from the serial adapter to the “T”-marked TX pad and the RX pad next to it.

Downloads and install Flash Programmer2 from TI.

Flash Programmer 2 (select the serial port, then CC1310F128)

USB Adapter : https://www.amazon.com/HiLetgo-CP2102-Converter-Adapter-Downloader/dp/B00LODGRV8?ref_=ast_sto_dp

Firmware: https://github.com/sycophantic/wyzeback

You can also backup your own firmware using this tool and command

cc2538-bsl.py -p com10 -r -l 131072 backup.bin

credit goes to Mr. Null from WYZE forum

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2 Likes
2

Thank you very much for the instructions and tools list. I was able to recover a few myself with your tutorial. I have one sensor that refused to enter the bootloader when grounding RX to GND. I think I was able to get into Bootloader by grounding TX and GND (solid red light) but was not able to flash, do device found. Any help would be greatly appreciated. Able to save a bunch of money reusing these in HA instead of purchasing more.