[LN882HKI] How do I flash Mini Smart Breaker RMW002 WB02A-0882H?

I have bought a device named Mini Smart Breaker RMW002 from AliExpress.
Looks the same as in this topic:
https://www.elektroda.com/rtvforum/topic4009765.html




When teared it down, I saw a board named WB02A-0882H with LN882HKI.




Soldered it to a flasher (from left to right - Vcc, GND, Rx, Tx):


The tricky part was soldering the boot pin to ground. The space for the iron is tight, but manageable:


The flashing went flawlessly:


With GPIO finder discovered the right config:


Here is the store page:

To flash the Mini Smart Breaker RMW002 (WB02A-0882H), you need to upload firmware via UART communication. This device uses the LN882HKI chip, a new type of Wi-Fi chip often loaded with open-source firmware like OpenBeken for local control via Home Assistant instead of using the Tuya cloud.

1. Hardware Preparation
USB-to-UART converter circuit: Requires 3.3 V logic support.
Power supply: A stable external 3.3 V power supply (such as an AMS1117 module) should be used because the 3.3 V power from the USB-to-UART pin is often insufficient for stable chip operation during flashing.
Connecting wires and soldering: Solder the connection pins directly onto the WB02A-0882H module.

2. Pinout Diagram
You need to solder 5 wires connecting the UART circuit to the module as follows:
VCC: Connect to the 3.3 V pin.

GND: Connect to the ground pin.

RX: Connect to the TX pin of the module.

TX: Connect to the RX pin of the module.

BOOT (GPIOA9): This is the most important pin. You must connect the BOOT pin to GND (strong) throughout the flashing process to put the chip into bootloader mode.

3. Procedure
Soldering: Solder the wires according to the diagram above. Note that the BOOT pin is usually quite small and in a confined area, so be careful not to damage surrounding components.
Software Connection: Use the LN882H_CMD_TOOL or a dedicated flashing tool for this chip series (such as the latest version of BK7231GUIFlashTool which supports LN882H).
Backup: Always back up the original firmware before flashing new firmware so that it can be restored if needed.

Flash Software:
Keep the BOOT pin connected to ground.
Power on the device.
Select the firmware file (usually in .bin format) and press Start on the firmware.

Note: If the process fails, disconnect the power, unplug the USB-to-UART adapter, plug it back in, and try again from the beginning.