I am looking to purchase a EmonEVSE WiFi Connected EV Charging Station (Type-2) - Shop | OpenEnergyMonitor and I have a few questions before I place the order.
- I am not sure whether to go for the wifi or the LAN option (LAN would be more stable but would require a very long cable run)
If going to wifi, is it possible to easily upgrade to LAN in case I have issues?
- The hardware button on the side? Do people find it handy or no need since it can be controlled via the app or Home Assistant easily?
- Do I need to purchase anything else along with the kit above?
Thanks in advance
The LAN version also can connect via WiFi so if you think you may want to upgrade to LAN later that is probably the better option.
My unit doesn’t have the button and I kind of miss it on occasion, but not enough to install the button I have sitting on my desk 
It would be kind of handy to override the sleep state and force a charge, but entirely depends on your use case.
You may need an earth rod installing and if you want to claim the OLEV (or similar) grant you will need to get it professionally installed based on my install, but @glyn.hudson can probably give you a more accurate answer.
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Thanks for the reply.
Yes I will get it professionally installed for the grant.
And in terms of Home Assistant I can see the integration here OpenEVSE - Home Assistant but it doesn’t seem to have any control options i.e if I want to change from full charge to Solar only so that I can set up some automations, change the charge rate, or disable the button at the side of the charger.
I don’t have an Emoncms but I do have access to the import/export sensor from HA which I will be passing to the charger.
Is there a way to change the config on the EmonEVSE via mqtt in that case instead?
On V3 you can change parameters via RAPI over MQTT, in V4 we are replacing this with a REST(ish) API over HTTP, this may be available over MQTT later but MQTT is not really designed for request/response patterns so this will be done later when the HTTP API has been stabilised.
Thanks for the clarification, looks like it is better to just tick all the extra options like button/LAN card for future-proofing 
Using REST for remote control will do the trick as well provided the requests can be easily sent from Home Assistant.
One last question, can the Amps be changed on the fly via wifi while the car is charging or does charging need to stop, set the new value and start again?
Yes this is possible, you can make a claim on the EVSE and adjust the charge rate.
Awesome, interrupting charging isn’t great for the car and it always sends error messages if it detects an interruption.