With all components delivered, I started populating my OpenEVSE Arduino Shield.
I'm just building these two circuits: one for switching the relay from pin D8:


And one for sending the (J1772) +/-12V square wave indicating the chargers max amps to the vehicle:


I am skipping the led because I am attaching a sparkfun 1602 LCD.
This is what I ended up with, mounted in the DIN case on an Arduino:


The flatcable on the bottom connects to the display.