[BK7231N] (DIY) Mini Smart Switch UNSH SS8839-16A-W

This is a short teardown of the DIY Mini Smart Switch 2-way from UNSH model SS8839-16A-W based on BK7231N.
It uses custom PCB, so no Tuya module to replace, already bought one



Brand: UNSH - Tuya
Model: DIY Smart Switch SS8839-16A-W
Chip: BK7231N on board
Seller: AliExpress 16A Tuya WiFi Smart Switch 2-way



The switch is very easy to open so i wont go into details, but remember, this device it's using high voltage, so make sure it's not connected to the mains.






Used tuya-cloudcutter to flash OpenBK (had to setup in SmartLife/Tuya app - after first flash device did not connect to cloudcutterflash AP)
Followed this instructions tuya-cloudcutter INSTRUCTIONS.md
and video Flash OTA using tuya-cloudcutter
> By firmware version and name
> ~ Mini Smart Switch
> 1.2.1 - BK7231N / oem_bk7231n_control_switch
OpenBK7231N_UG_1.15.648.bin (CCtr flash)

Requirements:

RPi to install GitHub tuya-cloudcutter
Firmware OpenBK7231N_UG_1.15.648.bin
Router/AccesPoint for temporary local cloudcutterfalsh AP
some patience and persistence

Device could not connect to cloudcutterflash AP after reboot,
so I needed to create a "second" cloudcutterflash AP on spare Router with internet connection as stated in Note: of INSTRUCTIONS.md.
Had to disable WiFi on RPi - tuya-cloudcutter
After that it was possible to enter WiFi credentials thru Tuya app.
Turned off "second AP", enabled tuya-cloudcutter and the process of flashing OpenBeken continued.

Pin settings for this device.

TglChanOnTgl - 6 - PWM0 - ch0
Rel - 8 - PWM1 - ch0
Btn - 23 - ADC3 - ch0
LED - 26 - PWM5 - ch0

Simple test environment






Payed 3,63 € For UNSH Tuya 16A Tuya WiFi Smart Switch 2-way and 2,18 € form ESP-02S module witch I could not use.
with alternatives
~12 € is the price for Athom 3 Way Relay for ESPHome if buying 3 pieces with shipping
or
9~13€ Sonoff MiniR2 from local store

It was worth for the experience, tinkering, flashing, rebooting