Create hmi_bridge.ino

[kotovasia5120]

Optional support for an HMI bridge between the display and the main controller has been added.
An ESP32-C3 HMI bridge sketch with transparent forwarding of Nextion messages has been added.
Support for a matrix keypad with transmission of Nextion events has been added to the HMI bridge.

Purpose:
This allows connecting physical buttons and a matrix keypad without modifying the main controller or the display, while maintaining backward compatibility.
It makes it possible to add functionality to both closed Nextion displays and open CrowPanel displays without increasing wiring complexity or affecting the reliability of the main controller.
This approach also allows placing the main controller behind the machine and running only a few wires to a panel with a large number of physical switches.

How to use:
In hmi_bridge.ino, configure the pins and the MATRIX_COMPONENT_IDS map.

Planned:

1. Addition of encoders and switches.
2. Ability to use the bridge instead of a display as a web-based control interface to reduce the cost of the initial build.

Initially, the ESP32-C3 Super Mini board was chosen as a low-cost and capable option, but almost any other board can also be used.

[kachurovskiy]

@kotovasia5120 that's a lovely tool. I'm not sure if nanoels repo is the right place for it though. I can't maintain this code as I don't plan on building the bridge physically and therefore can't test or bug fix.

Seems much better for this to live in one of your public repos - you can commit without pull requests - ideally fully documented with PCB, assembly and usage instructions, ideally a video too - I'd be happy to link to it and promote on my channels.