[werk_ag]

Of course I can see a reply too from the Weewx developers saying something like "many many people are using Weewx with Davis weather stations, do you not think if there was a bug that it would have been seen by them?"   But we shall see.

Exactly    Then the conclusion that the problem should be (perhaps) related to WeatherDuino. However WeatherDuino works even with the original Davis software.
Lets go ahead...

Thanks for the explanation. As far as I know have disabled the hardware reading some time ago when you first suggested it. But now that I know of the clicks I will go back and look at the rain as it happens.

If you can explain a little further should I see a 'click' number appear in the "rain" each time the bucket tips? If not can you explain what I should look for please.

Honestly I don't know what Weewx show on the logs, what I can say it that any rain value sent in the LOOP by a Davis weather station is always in number of click, even the rainfall rate is in clicks / per hour.

Please check the Vantage Pro, Vantage Pro2 and Vantage Vue Serial Communication Reference Manual - Page 23
https://www.davisinstruments.com/support...s_v261.pdf

I don't know how you are testing the system, but what I really think is that there isn't any problem nor with Weewx nor with WeatherDuino. Perhaps things work differently to the way you are expecting they work.
Lets suppose you have a Rain Today reading of 2.0mm shown on the WeatherDuino display. If you start a fresh install of any weather software, all of them will start showing you a Rain Today of 0 (zero) don't expect that any of them will show the 2.0mm that you see on the WeatherDuino display. And why? Because when you start a fresh copy, the software will store the total number of rain clicks for today as an initial value, and then will start count from that value onwards. The weather station resets the rain today clicks value at the start of each meteorological day.

If you have the TX board and rain gauge still in your work bench, try to start WeeWx (without any previous records or logs - delete them all) then manually move the tip bouquet of the rain gauge. Rain should increment in WeatherDuino display, and on WeewX too.
Important:
Set the correct collector type in the TX software

#define COLLECTOR_TYPE  0.280  // Please note: Values must be in metric units. Max. resolution: 3 decimal digits

If your rain gauge isn't a 0,200mm (default Davis metric rain gauge) type, then you should also set a multiplier on Weewx.
Multiplier = collector type / 0.2 (values in mm)