Excellent project, thanks for sharing!
I assume the 4 GPIO-connected inputs support analog input, mapping something like 0 a 5V to 0 - 255 values. Is this correct?
And these 4 pins also work as outputs?
To control mains voltage the outputs will be connected to relays. Do you know some ready made or DIY din rail 230V relays supporting 10 Amps or so that can be controlled with the 3.3V and low current ESP32 pins output? I guess the relays will need some transistors for this. I haven’t found any mains power relays with this design.