PCB design

The PCB design is made using eagle. There are 2 boards, a board for the rotary encoder and a board for the ESP32 processor.

I used my CNC router to make the PCB using isolation routing. If you want to use a PCB service for the board, you may need to adjust the design (rename layers).

The connectors on the board are 2.54 mm pitch. The 4 pin power supply and mist/air coolant input is a phoenix type connector, the injector and relay connectors are JST-XH.

There are 2 voltage regulators (5V, 12V) on the board. I used 2 small "step down converter modules" to reduce heat dissipation so the board can be put in a small enclosure.

You could wire wrap the hole design on a breadboard or by using a processor breakout board that has screw terminals.

For noisy environments like my lathe, adding 1500 ohm resistors at the display side between the display VCC pin and the display SDA + SCL pin reduces the chance of display data corruption. Reducing the i2c, frequency especially when using longer cables, also helps.