How to program a Shelly PLUS 1 via serial port

[wchulze]

I want to program a Shelly PLUS 1, the latest model, with Tasmota via the serial interface. I have carefully searched the Tasmota documentation, discussions and issues. After that I am more confused than knowing which Tasmota version I should use to flash the initial software serial.

The website
https://templates.blakadder.com/shelly_plus_1.html
doesn't really help, as the Shelly would have to be opened in order to find out the version.

At the moment I think it should be tasmota32solo1.factory.bin. Which programming software with which parameters is currently recommended?

Thanks for a hint

[Noschvie]

Use https://github.com/tasmota/mgos32-to-tasmota32 in case of the current firmware is less than v1.10

[sfromis]

In case of wanting to use the serial port, I'd expect it to work with standard ESP32 flashing tools. The Tasmota Web Installer is the one we usually recommend, I think that you may have to make sure to select "Tasmota32 Solo1 (english)" in the dropdown, not needing any downloaded binary.

And no, you do not need to open it up, the serial port is accessible through the plastic cover, as long as you do appropriate wiring.

[wchulze]

Thanks for the info.
I compile my Tasmota version locally to set my WLAN access data. For this reason I don't want to use a web installer, because the password is in plain text in the file.

What about the flasher from Jason2866
https://github.com/Jason2866/ESP_Flasher

Are there other options?

[sfromis]

You can still use the web installer with a local file, just use drag/drop to the designated area clearly labeled near the bottom of the page, or click the upload button.

The other web installer you linked now can also be used. And obviously, esptool.py always works. Some flashing tools have presumptions about being based on ESP8266, which may not work well with ESP32.

Note: "web installer" means that the tool is hosted on a web page, it does not mean that a local file will get outside your network, as the processing is done in the browser.

[wchulze]

Well, thanks for the detailed explanation.

[wchulze]

I still have a question: Should I flash
tasmota32solo1.bin
or
tasmota32solo1.factory.bin
into the Shelly? I'm not quite sure yet.
I simply want to switch the relay on/off via Alexa, not more.

[sfromis]

For initial flashing via serial, always use the .factory.bin bin variant. The first one is for OTA upgrade when Tasmota was already installed previously.

To configure, apply the template from https://templates.blakadder.com/shelly_plus_1.html (see the how-to link in the left column).

[wchulze]

Ok, thanks