So I wrote a VE.Bus (mk3) <->mqtt utility to hook my Multiplus into my HA. The VE.Bus doc 3.14 (last updated 2017! but it's the latest available, as far as I can find) covers most of what I need -- the ability to monitor the various voltage/current/frequencies, to turn the charger on/off, and to adjust the max load from shore power. Got all that working. I was able to figure out how to get the serial # off the unit by sniffing VE.Configure talking to the serial port, but that was pretty trivial (It comes right over in text, so it was easy to find). There are a couple things the VE.Configure tool can do that aren't documented and, before I dig further, was hoping somebody might know, or have a document:
A> How to identify the model that is connected? I assume it grabs some sort of product ID and then has a table. Suppose it may just use some part of the serial #...
B> How to read the Aux 1+2 ports, and control the aux relay? The Multiplus-II manual has very little on what these aux ports can actually be used for. I'm hoping I can get a voltage reading on them, but even it's just like, a contact switch, that'd be useful too.
C> How to get the internal temperature of the unit? I'm actually not sure this is in VE.Configure (it's not in VictronConnect, at least that I could find) but I assume it must be available somehow.
It doesn't seem that the mk3<->dbus code for Venus is open source (If it is, please point me in the right direction). Can't really find any other resources on the mk3/ve.bus protocol past that one document either.
Yes, I know I can install Venus on a rpi, and it would probably do this stuff. Even if I wanted to add another device into my system sucking power, you can't even find an rpi 3b+ for less than $150 these days anyhow.
Anyway, if anyone has links or access to any resources and wants to help (Victron employees maybe? :D), let me know. Thanks.
