I found out at Kruidvat ( a retail store in the Netherland) they sell Smarthome products based on Tuya. They are cheap and reflashable. I bought a door sensor, just to check what is inside. I can confirm the doorsensor has a TYW3S. It looks as similar as the line up Action has with their brand LSC.
Link to product: Tuya doorsensor
I tried to flash it with my serial adapter ( TX, RX ,GND, 3V3 and GPIO0 grounded while flashing, but it failed.
I tried the tuya-convert method, that failed also.
Is it because the TYW3S is still soldered on the board?
I found similar products, but none of the methods worked for me. For example these ones.
Also want to mention that I’m familiar with flashing tuya devices and know about the MCU part, but can’t figure out how to flash this thing.
Can anyone assist me with flashing either ESPHome or Tasmota on this thing?
My last solution is to desolder it with a heatgun. But that is my last resort.
I’ve added some pictures of the guts.
I’ve found this, will try to flash again with RST of the MCU connected GND.