Funnily enough I was just able to get this to work this morning.
These devices use the new firmware and an external MCU so it is a little complicated and requires some soldering. OTA will not work at all.
The relevent information that led me to the solution:
- Identify the chip which is a https://tasmota.github.io/docs/devices/TYWE3S/
- Identify there is an external MCU - http://www.datasheetcafe.com/bs003f3p6-datasheet-8s003f3p6-microcontroller/
- Ground the correct pins to put it into flashing mode
To get it into flashing mode you have to connect it all to the external FTDI (I use the FTDI FT232.
Then you need to ground the GPIO Pin0 on the TYWE3S to ground, keep this connected until the end
Then you need to ground the RST pin from the 8s003f3p6 as well, this stops the MCU from taking over the TX/RX pins. You will notice that when you power the FTDI, all the LED’s will come on, when you ground the RST pin, only the middle LED will be on, but dim. I just held it there with some clips during the flashing process.
Once all this is done, you can go ahead and flash Tasmota as per the instructions.
I’m at work right now but when I get home I’ll put a photo instruction set up on GitHub.