Sounds like 2 problems:
Service level detection not working properly
Pilot not working
Both of those systems have a ground in common. We would recommend checking the ground connection to the OpenEVSE controller board and the AC Input grounds.
The chips that do the detection of L1 or L2 are connected to AC_Test lines. If you reset the station while it is plugged into the vehicle the Auto detect is disabled. The relays are only cycled if the vehicle is not plugged in.
That does not explain the problem of the station changing from Connected to charging.
There are only 3 things that could affect the detection of state from Ready, to Connected to Charging.
For proximity I would verify when the handle is plugged in you can hear the switch click. If it does not click the system may think the button is still pressed down.
For proximity the key is hearing the click when you RELEASE the button after connecting to the vehicle. If the button remains in the closed state the vehicle will never start charging.
The behavior you describe is correct.
If OpenEVSE detects a vehicle is connected (via the pilot line), OpenEVSE will skip cycling the relays to auto detect the service level and default to Level 1. As soon as the vehicle commands the relays close, then the AC_Test lines read voltage on the AC_Detect chips and the service level is set to the correct value.
Based on your descriptions the pilot is fine. I would still check the button is opening (Clicking) when you release the button after inserting into the vehicle. You may also want to check the connectors and termination on the relay, if the vehicle does not see voltage or the drop is too high it will reject the session and change from "Charging" back to "Connected".
Hi John, Did you ever solve the problem? My Model 3 arrived yesterday but I'm unable to get it to charge with the Tesla just indicating an EVSE fault. I built the openEVSE about a year ago in anticipation of receiving the vehicle so it has never been 'real world' tested other than via the optional separate test board I built to ensure that it was working correctly. My difference is that I'm running EU Firmware (max 32amp) and using a Type 2 connector in lieu of the J1772 which although different, shouldn't be causing the problem.
No I didn't get a chance to dig into this much more. I'm mainly using my model 3 evse when charging at home, but also have a supercharger nearby and use that as well. I do still want to get to the bottom of this, but haven't had a chance to pull things apart. I am suspecting the relays are perhaps not making good internal contact and that's where a voltage drop is occuring. Its about the only thing that makes sense. I have been meaning to order some new relays and/or pull these out to test them but since I can charge with my tesla evse its been at the bottom of my priority list.
Thanks John. I have submitted a separate ticket to seek assistance from the experts and in the meantime, I will have to use one of the local public chargers.