It needs a full web server to be able to host the OpeneVSE WiFi interface e.g here’s a live demo: http://openevse.openenergymonitor.org/
It’s just a case of connecting up Rx and Tx or the easiest way is just be to use a USB to serial adaptor. Here’s a photo o a prototype
Run the OpenEVSE WiFi server as documented in the readme: GitHub - OpenEVSE/openevse_wifi_server. e.g where /dev/USB0
is the serial port that the EVSE controller is connected to.
npm start -- --port 3000 --endpoint /dev/USB0
However, I would recommend anyone wanting to add Ethernet to the OpenEVSE an ESP32 Gateway instead of a RaspberryPi for the reasons given above: