Shelly Pro 3EM support for dbus-modbus-client 1.58+

[rkapsi]

Disclaimer: This PR is based on @Jalle19 work and he helped me to make it ultimately work. All glory goes to him!

This PR should add generic support for all Shelly Modbus EMs to dbus-modbus-client 1.58+ using just the dbus-modbus-client's own API. There is no custom code other than just defining the device. It's only a matter of enumerating them.

[Dennis-LB]

@rkapsi Guide how to connect the Shelly Pro 3EM ?

[rkapsi]

On your Cerbo GX go to Settings -> Modbus TCP/UDP devices -> Saved devices and enter your Shelly's IP. It will immediately show up under Settings -> Device list.

[Dennis-LB]

@rkapsi Can't get it to work... have now tried 3.42 (latest release) and ran this --> #4 (comment)
But still nothing... might need to downgrade to 3.40 or .41 ... if possible

[rkapsi]

I'm sorry if this stuff is confusing but this PR only works with 3.50 and later (current beta).

[Dennis-LB]

@rkapsi

I'm sorry if this stuff is confusing but this PR only works with 3.50 and later (current beta).

Well... got it working on 3.41, but not on 3.50

[Jalle19]

If Victron would show some interest in merging this then maybe we wouldn't have to provide user support for years on end.

[rkapsi]

@Dennis-LB very cool. It appears dbus-modbus-client 1.58 has been backported to Venus OS 3.4.

$ cat /opt/victronenergy/version 
v3.42
Victron Energy
20240910081535

$ grep VERSION /opt/victronenergy/dbus-modbus-client/dbus-modbus-client.py
VERSION = '1.58'

When it happened I don't know but I'll update the PR description to make it clear that it's a dbus-modbus-client 1.58 dependency rather than Venus OS. With that said I'm on v3.50~25 (and all the betas before that) and it's been fine and the only thing I keep track of. It's difficult for me to provide support for something I don't use.

[onceuponatime78]

I just recognized that with the latest 3.5034 (before that I had 3.5030 running) the rootfs became read-only and therefore its unfortunatly not straight forward again to patch this - this is especially a bit sad as the available way in venus via websocket is not working reliably. Did you guys figure out on how to patch this in anyhow?

[rkapsi]

Until Victron accepts the PR or does their own thing there's no way around it. Every time there's an update you need to set the root password, ssh into it and do the dance.

I keep the shelly.py file in my /data directory and symlink it to /opt/victronenergy/... To make life easier and not having to do the import you can choose to override one of the other EMs (say ABB). This dance could be automated if there's interest but it's kind of weird.

[onceuponatime78]

doing the dance wasn't the issue for me...problem now is that on my Ekrano I am locked out now of any modifications to items in the rootfs, hence adding the import is not possible any more

[Jalle19]

@mpvader I've been waiting almost 1,5 years now for this to be merged. If Victron won't merge this due to conflicts with their own energy meter offering then please say so and close these requests.

[rkapsi]

To whom it may concern I also added support for Shelly's Monophase profile.

[patrick-dmxc]

@rkapsi @Jalle19
Hi im whatching this since you opend the PR because i also did an Implementation of some Meters esp. of Janitza., which would allow it to Build ESS with mouch larger scale as all other supported Meters
And it seems like there is no interested in contribute of the Community for Implementing and/or keep 3rd-Party Meters in there Code.

[Jalle19]

Would be a good conpromise if there would be a plugin system where users can easily add third-party functionality, like support for other meters. AFAICT there's no such thing at the moment though.

[rkapsi]

For me it's fine if they don't want to include OSS contributions but they should say so. Then I'd move on and write my own install script.