Following the N3FJP[1] design, I created an optic coupling interface. Rev A can be built for RTS or DTR (0 Ohm Resistor to select option) or interface with a micro controller via pins.
The interface works well but switching apps while transmitting you can hear a little stagger. I created a simple cli app that translates from keyboard to serial allowed me to work from a headless raspberry pi eliminating that issue.
