ESP32 generic board wiring

[abonforti]

Hi, just discovered this awesome project and I'd like to try it myself.
However, I'm not really sure about the wiring.
I got a NodeMCU ESP32 board which is my candidate to try. I believe my FTXS25DVMW unit has a S21 port (at least it's indicated in the manual), but I am unsure about how to wire the ESP32 to the S21 port. I have read https://github.com/revk/ESP32-Faikin/wiki/Wiring#s21-connector but it's mentioned to connect to "logic", might be a dumb question, but the "logic" is intended to be the ESP32 board or a logic level shifter is required?
Because from the aforementioned link if "logic" is to be intended the board, it just looks like a serial connection + 12v to power the board, am I correct?

[revk]

The software does not care - you need a Tx and Rx pin, but they can be any usable GPIO and can be inverted or not.

However, depending on the model, the Daikin will typically work at 5V not 3.3V. Some models will indeed "just work" when driver Tx at 3.3V and the ESP32 will typically tolerate 5V, but not all models are so. Hence the need, generally for some form of level convertor.

The board design uses FETs and pull up resistors and a diode to allow a possible 5V reference (pin 1) from Daikin, which is present on most models, but to otherwise drive as open drain as most Daikin models have internal pull ups.

[tigers75]

Thanks, I was looking for the same thing. What it's still not clear to me is what GPIO is Faikin using for TX and RX? I want to replicate it with a generic ESP32 mini S3 + DC-DC buck converter from 14 -> 5V and a level shifter for communication, I just can't find in the docs which GPIO of the ESP32 Faikin uses for TX and RX. I see mentioned in some other forum GPIO 16 and 18, is this correct?

[revk]

You can configure to use any GPIOs

[mikelawrence]

This information is also present on GitHub Faikin PCB page. The Readme mentions the GPIOs used. The Kicad schematic is also a great source of information.

[tigers75]

Well, to be honest that page is not very clear: it mentions that the port used are printed on the board and there's an image FOR EXAMPLE, so I guessed that the port used may vary. Nice to know that it can be customized anyways.

Thanks to everybody for the help.