I have a Zero Cross Tail attached to pin 2 on an Arduino Due to dim lights. I need to expand the number of lights that I can dim so I would like to add a second Arduino Due. Unfortunately I can no longer buy the Zero Cross Tail and building the equivalent is beyond my capabilities and comfort level. I was wondering if I could somehow attach the interrupt line coming out of the Zero Cross Tail to both Arduinos? Would this work if I connected the ground between the two Arduinos?
This website shows the schematic of the Zero Cross Tail.
https://os.mbed.com/users/4180_1/notebook/powerssr-tail-and-zerocross-tail/
The suggested wiring for the Zero Cross tail is connection C is wired to the Arduino interrupt input pin and connected to a 10K resistor to the VCC of the Arduino. Connection E is wired to Arduino ground pin.