[werk_ag]

Not sure if the current state of my system will be of any help, but if I can assist I'll be glad to do so.

I think it is enough to test the use of the SHT31 on the RX and WD unit.
Could you please give me by PM and email address to send you the modified software?

The WD unit is working ,except for not communicating via RF yet. I suppose the inside temp would show on the TFT display when connected and configured.

The WD unit can show on the TFT display the inside temp received from the main unit (RX) or the inside temp from it's own T / H sensor.
Having a T/H sensor connected to a WD unit it's not mandatory. This can be useful when the WD unit is placed in a different place from where the RX unit is installed (some people have WD units in several location of the house)

Haven't figured out how the RX unit configuration test mode works yet.

When a RX unit boot up, it will wait forever until it receives from a TX unit, data of Wind, Rain and outside T/H. This procedure it's important to correctly initialize the unit, however most people want to test the RX unit, even before they have a fully working TX unit, so a test mode was added. It allow the RX unit to jump the initialization procedure, and show some data on the LCD.
Keep in mind that after running the RX unit in test mode, you should program the RX unit again with test mode disabled, and then perform a factory reset (pressing the push button for 5 seconds).

Thanks