OpenEnergyMonitor Community

EmonEVSE with ethernet?

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Thanks for the kind words. See the WiFi gateway docs for info on how the API’s work to control the charger:

Here is a live demo of the web interface:

Yes, it’s available in kit form:

Oh, they have the same name (EmonEVSE / OpenEVSE)? I was thinking about this one: I want to have the type 2 connector. Friends come over with their charging cable and all can connect to type 2.

The EmonEVSE (non-tethered) is fully pre-assembled. While the OpenEVSE (tethered) is sold as a kit.

I agree, non-tethered is best for flexibility. It can always be made into a tethered unit by keeping a cable connected.

That is ok, I can still take a look inside and learn from that. Nice with the CE mark too I guess. But yes, this was also the unit I was talking about when it comes to cabled network instead of wireless. Will that make a difference in the chance of it becoming a reality?

Wired Ethernet version will not be available for some time. Existing units will be easily user upgradable when Ethernet connectivity is ready. The WiFi gateway module is an easily swappable separate unit.

Wired Ethernet connectivity is now available, see:

Any schedule when this would be back in stock? Could vacate one wifi access point set up only for OpenEVSE… @glyn.hudson

Apologies, we have plenty of stock of this module. For some reason the stock count on the store was incorrect. Thanks for letting us know, it’s been resolved know. It’s back in stock :+1:


As you may know I have updated the old ESP8266 to 2.9.1, what, if anything apart from the Ethernet connection would updating to this module give me?


Just an Ethernet Connection.

If you don’t require Ethernet I would recommend the ESP32 WiFi module:

Going forward the ESP8266 module will no longer receive updates (due to memory limits), we will be focusing on the ESP32. Currently, there is not much differance between the two as we have managed t back port many of the newer changes to the ESP8266.

How easy would it be to create an RPi interface?

Possible, OpenEVSE web-server can be ran on a RasPi, there would need to be a DIN 240V > 5V power supply inside the EVSE enclosure.

We did consider this at one stage, however the RasPi is not really suitable for the environment e.g cold / very hot temperatures and was not considered reliable enough at least not without modifications. The cost is also significantly higher than an ESP32. It’s often easier just to use a wifi extender which avoids having to run an armoured Ethernet cable to the unit.

An interesting option is a special EV Ultra cable with 6mm CSA conductors + datalines, it’s very expensive though!

I was suggesting just the same functionality as the ESP i.e. does the communication and any switching. I could not find anything that tells you what the coms/GPIO connections are from the ESP module. Is it just serial?

Cheaper than a Pi Zero?

I really don’t think they are any less robust than an ESP8266/32 IMHO.

How do you power the ESP modules currently?

Hi Brian

I understand your personal preference of the pi rather than ESP.

One thing to consider is loss of power. We live in a small town with somewhat flaky electricity supply. We probably get 2 or 3 power cuts a year. On top of that we get a lot of brownouts. Brief so some clocks need resetting and others don’t. I was using a number of pi’s as edge monitoring devices and had issues with the SD cards causing issues after power cuts. I switched them all to esp over a period of time and have had no further issues. They all come back on without intervention after a power event.
Power is bad enough that when we recently added a battery system we used Lux inverter that has a permanent emergency mains output. We used this to add a few 13 amp sockets to use as USP for IT equipment and our heating system.

Yes absolutely although I have yet to experience problems with a Pi after a power cut. One thing to consider is if it is the loss of power, or a surge/spike just before that is the issue. I run all my Pis either off a UPS or off a surge protector.

Yes, it’s just serial. The RasPi would just be doing the job of the ESP. The EVSE controller would still handle to EV communications.

Pi Zero is not available for commercial use. But yes, it is cheaper once SD card and extra development time to manage a full embedded Linux system is factored in.

There is nothing stopping a user using a Pi instead if they wish, the web server has been tested to work on a Pi and the GUI is shared.

Via a 12V > 5V converter, but the power requirement is low


Maybe, however, you could just have an interface to the serial comms - i.e. emonhub? There is really no need for a full embedded Linux System - just the serial comms component.

Can you publish it? Plus a bit about the physical connections required. Is the detail about the serial comms already out there?

What is the output? I’m not suggesting a Pi4!

If someone wants an Ethernet solution, a serially connected Pi could be a very economical way of doing it.

It needs a full web server to be able to host the OpeneVSE WiFi interface e.g here’s a live demo:

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: 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:

Interesting. Actually I was wondering if you need the openevse server, or could just send the appropriate commands via serial?

I see there is a node.js interface so that answers that question really.

As an aside @glyn.hudson, what is that enclosure? Is it designed for the DIN rail?