I have an OpenEVSE that I bought off of someone who had built it. Its about 4.5 years old.
My OpenEVSE uses an Adafruit LCD Shield. Will this display work with the v4 controller? Will the button work as well? The button currently works as intended on my unit.
Yeah, the Adafruit LCD should work just fine on controllers old and new. The OpenEVSE LCD does add additional safety with temperature sensors.