Marlin CNC pendant V3.0 ESP8266 version

Update:
Version 3.0.1
Fixed a bug that some movements of encoder during BLOCKED status were executed after switching back to normal mode.

This is a remix from TheOrneryMaker's version of the CNC Marlin pendant.
https://www.thingiverse.com/thing:5362454

I ran into performance issues with the arduino Nano (fast rotation resulted in irrating moves back and forth) and other strange effects. So I decided to go all in, port it to ESP8266 (will also work on ESP32), added I2C-PCF8574 module to the keypad and make everything interrupt-based.

Here is the list of vhanges and features:
Version 3.0, Nov 7 2022

Keypad and rotary enconder now fully interrupt capable for smoother operation
changed to ESP32/ESP8266 compatible interrupt capable I2C encoder library.
changed to PCF8574 I2C keypad library
reduced false detection of fast encoderrotation
Display "BLOCKED" status of safety switch
Added V1 engineering logo
Added OTA Firmwareupdate (optional, choose with OTA=true in variables)
Changed B-button from A-axis to a diagonal move +x+y / -x-y
Added C-Button for a diagonal move +x-y / -x+y

Hardware needed is the same as in the original V2 version. Just add a PCF8574 module (cheap on Amazon or Aliexpress), a 220Ohm resistor, a 5mm red LED, LED reflector mount and exchange the Arduino Nano with an ESP8266 (e.g. NodeMCU 0.9 ESP-12E) or an ESP32 devkit V1.

Wiring is documented in the code!

Case is the same as with the original version. I add the unchanged STL's for completeness.
Some videos of it in action

https://youtu.be/XBwzNp-7NvA
https://youtu.be/LAAQQS1KYp8
https://youtu.be/b0EgFXaEPNc
Thanks a lot to TheOrneryMaker for all the initial work he did! I hope, you like the V3.0!