Homedig2 are now Victron Solar system, and Energy monitoring aware. See the mobile Node-RED UI screen - updated every 3 sec, with the energy details. It uses the homedig2 framework, to collect info from both the Victron MQTT server, and from Shelly EM - connected to stove, geysers, and swimming pool, on one canvas.

See Shelly Cloud EM device here. They are sold with up to two independent measuring channels, from 50A to 120A ea, with a 2A contactor control - to for instance switch a geyser on/off via a Contactor.

I am using the Victron Energy EasySolar-II 48/3000/35-32 MPPT 250/70 GX Inverter Charger, where we enabled the MQTT service, which feeds the Energy information to homedig2. Homedig2 has components to interact with Victron MQTT channels, and periodically (I set mine to every 10 sec) do a call to the Shelly's CoAP interface, to fetch the Energy information. We use the homieTransforms.yml settings file to achieve that. See github.com/IoTPlay/ CoASetup section for an example.

The Interface shown is a small web inteface, built to view on a mobile phone's screen, using Node-RED's Dashboard and SVG nodes. It shows, with a refresh rate of 10 Sec for the Shelly devices - at the bottom (E-Meters), and 2 sec for the Victron information at the top The Victron part of the interface - is similar than what you can get with your Victron interface, when you visit - on your local lan http://nanopi.local (depending on router settings) . We also store all the refresh information in homedig2 Global Context homie-style structure, and is available for process management.


We are still working on an issue - where the retained messages, which does not refresh often, the biggest issue beign the Battery % in Blue - only refreshes every 20 sec, thus - if you want to see the correct Battery % - you have to open the interface- and wait for the refresh.

Next Steps - Benefits.

We are busy building an "Energy Management System" where the information gathered for the above, can intelligently  switch on/off for instance, smaller geysers, boreholes, etc, based on energy availability in the house. Furtermore, if the energy produced by the solars are not used, after the batteries have been charged, can then be sensed, and energy can then be set to automatically flow back to your DB board, for consumption by non-Victron inverter connected devices, such as in our case, the swimming pool, geysers, etc. (this is done by writing a negative Watts value to AcPowerSetpoint via mqtt).

And, why do we like Shelly? Because of the personal portal which stores your energy usage, accessable by API (we can read past consumption to combine it with same for Victron - consumption & generated energy), to combine the info for display - or analysis to find further optimisation potential. See the Shelly Cloud energy panel below.


Parts List.

If you want to build a similar system, you will need:


  1. A Raspberry Pi 3B+ upwards, power supply, housing, preferably hooked-up to your router with a LAN cable. (It is also possible to load all the server SW on the Victron EasySolar II's nanopi, but we have not tried this yet).
  2. Shelly Cloud EM device/s, with the right Amp clams - for you application.
  3. For the next steps, you will need wifi controllable switches, homedig2 can handle Shelly and Sonoff's devices.


The homedig2 stack will require an MQTT server, Node-RED server/s, within which homedig2 is installed. We use Docker to run all our servers on one Raspberry Pi.

For Apple users, but outside the scope of this post, homedig2 uses a homebridge server, also running on the Pi, as part of the homedig2 architecture, to present information to Apple Homekit. Unfortunately, Apple HomeKit is not yet Energy aware, thus not component on their home app to project energy information into - as shown above, but cool to for instance switch on/off your sprinklers.

Your Infrastructure:

You will need a stable wifi network, where the wifi reaches the Shelly EM devices installed in your electricity DB board, where you want to measure for instance geysers, swimming pools, etc.

And, if you are a friend of the IoTPlay team, and if you do not have any IT knowedge, and you want us to install / maintain the homedig2 system (after you installed the Shelly EM devices), you will need to allow us to get into your home network from outside, after you signed an agreement for us to do so.



Thank you to Philip Metz from http://justgreentech.co.za that assisted with the configuration of my Victron devices.

Thank you !