@z8lccda, you’ve just described my setup - Growatt SPH5000, RS485 to Waveshare and then onwards to Home Assistant.

I’m not aware of a wired equivalent to the ShineWiFi dongle, so I suspect RS485 is your only alternative. However, if you want to get to the data directly rather than through something like Home Assistant, I’d suggest reviewing some of the modbus musings of @cathoderay. His approach of querying modbus enabled devices with a few python scripts could well be just what you’re after for creating the csv files you want.

Posted by: @majordennisbloodnok

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I’d suggest reviewing some of the modbus musings of @cathoderay. His approach of querying modbus enabled devices with a few python scripts could well be just what you’re after for creating the csv files you want.

True networking for this is beyond my ken but using a single wire serial modbus connection over USB is exactly what I have done. It is very easy to do and once setup it just works. It does need whatever it is you want to collect data from to have a modbus interface/connection which is just two terminals (conventionally labelled A- and B+) and you need to have a RS485 to USB adaptor and a (mini) PC at the other end to plug the adaptor into, and that's it for the hardware. You can then either use HA to collect the data, or write your own python scripts. Personally I found using HA was more of a PITA than writing the scripts. The scripts use a python module called minimalmodbus to read the modbus registers, and then dumps the data in a csv file, all set up on a timer. The csv files are much easier to manage than even a simple database format such as sqlite (still I think the default HA option) as they are text files and they are seriously robust, something which in my experience cannot be said of HA databases. Backups are a doddle, just copy the csv files to another location.

The thread with the details on how I set up the hardware to do this is here. It describes a connection to a Midea heat pump wired controller, but the principles apply to any similar modbus enabled device. It's all there, at least I think it is all there, apart from the python scripts which I have yet to post (I've always been a bit nervous about their generalisability, but maybe I should stop worrying, and just post them). Strictly speaking there is only one essential script (<4kb, ~115 lines of code), which collects the data once a minute and write that to a minute data csv file. Next to this script is another one that processes the minute data once an hour to get hourly and daily data. All the data ends up in three csv files, minute data, hourly data and 24h (daily) data, which can be loaded into Excel to do whatever you want. Being csv data, it can also be read in python (eg for use in plotly, which I use for my main interactive charts) or R which I use for various analyses and to produce high quality static charts. Once you go down that rabbit hole you wont come out again for a very long time!     

Having had another little look around, it seems Growatt may well now sell a dongle that does both wifi and wired ethernet. This is a new development since I last looked.

https://en.growatt.com/products/shinewilan-x2

I hasten to add that this is not a recommendation; merely that the item is worth a closer look.

• Thanks folks. I had tried googling an ethernet lab adapter for the inverter but did not see the Shine WiLan-X2 in results, but it sounds very promising. I've emailed their customer support.. let's see what reply I get..
• If it does what I hope, it will be my preferred solution as I don't want a 'project' (yet 🙂

Well well well.. turns out my WiFi dongle is actually the Shine WiLan-X2.. 

So this is my route to wired ethernet connectivity,and will see what this leads me to next

Many thanks 👍🏻 

The simplest wired option is usually the Growatt Ethernet (LAN) dongle, which plugs into the RS485 port and connects to your router, replacing Wi-Fi. An RS485-to-Ethernet adapter (like a Waveshare) can also work and gives more flexibility for things like Home Assistant, though it requires some Modbus setup. For CSV data, once the inverter is networked, you can usually export it directly from the Growatt Shine portal or PC software and then open it in Excel for your own charts, no need to dive into Home Assistant unless you want to automate it further.