I'm trying to build a device powered by an EVSE's J1772 connector, and would like to know what the easiest way to trigger the activation is.
Based on my understanding, all I really need is an inline diode on the pilot pin, connected to passive resistor from pilot to ground (2.74k), and then a second resistor (1.3k) in parallel which can be activated with a switch. When the first resistor is connected (2.74k) the EVSE should think there's a car connected, and once the 1.3k resistor is placed in series (making a net resistance of about 880ohms), the AC lines will energize.
The proximity side of things is simply for the car's sake of knowing if there's a EVSE present or not - would be nice to use this to detect the button press on the gun to stop drawing power, but in this case I could also just turn things off by disconnecting the 1.3k resistor above.
If I want to find out the amperage of the EVSE I would then have to actually read the duty cycle of the pilot, which I probably won't need for this application.
Is the above interpretation of the signalling protocol correct?
(mods feel free to move to "off-topic" or a more fitting sub-forum if deemed necessary, since this is not a Leaf-specific engineering topic, but I do sometimes see related tech discussions in this section occasionally )