A friend of mine asked me for a solution to get data out of his solis system because he didn't find any working solution for his system on the net.
His system consists of a Solis S5-GR3P(15K) https://www.ginlong.com/solarinverter3/3-20kw_s5_de.html
and the new Wifi stick S3-WiFi-ST https://www.ginlong.com/accessories5/GPRS&WiFi_Data_Logging_Stick_de.html
the location is Germany (maybe it makes sense to know it)
I did a research and found a solution of Grob6000 on git. https://github.com/grob6000/esphome-externalcomponents
But this solution didn't work, digging a bit deeper i spottet that the communications is completely different.
Depending on that i'm completely new to ESPhome and not good with python and C++ (i prefer old C) , i took Grob6000's code as a base and applied several changes to meet the different protocol and got a solution that works for my friend.
IMPORTANT: The inverter MUST be configured with (Modbus) address set to 1 !
You can try if my solutions work for you, it works stabil for the above mentioned system.
A sniffing component
dokumentation: Docs/s5_gr3p15kww3
tests: Tests/s5_gr3p15kww3