One more question: the supplied cable is generic—in my case, with the S21 connector, do I connect it one-to-one?
If it is being supplied with an S21 cable then yes you just connect the esp module to the Daikin S21 port with that.
Hey everyone.
I’ve ported Faikout’s CN_WIR to ESPHome 
Check on repo GitHub - davideciarmiello/esphome-daikin-cnwired: ESPHome Component for Daikin Splits using the CN_WIR port. · GitHub
It’s now possible to control Daikin CN_Wired directly from ESPHome, making it easy to integrate with Home Assistant and take advantage of the ESPHome ecosystem.
It was quite a fun challenge involving reverse engineering and adapting the original driver to ESPHome’s architecture, but it’s finally up and running! 
Let me know if you use it, if there’s any features you’d like to see, problems, etc.
Is S21 protocol also supported ?
No, this is a component for only cn-wired protocol. There is already a s21 component
There is already a s21 component
You mean S21 is already supported by ESPHome ? where?
Is it better to use the ESPHome version over the Faikout firmware, and if so, why?
I’ve only used the Faikout version but the main advantage I can see for using ESPHome would be that it can use the ESPHome API - so no MQTT broker is required.
Faikout is much more generic, and that is its strong suit.
Regarding ESPHome, communication with Home Assistant takes place via APIs rather than MQTT. It is highly customizable; you can create sensors or automations directly within ESPHome and make it as autonomous as you wish.
One more thing: I fixed a few bugs during the ESPHome development. For instance, if an invalid command is sent, the air conditioner’s state is re-read. This prevents issues where—if you reboot the board while the AC is on—it appears turned off in Home Assistant because it failed to read the current state.