It's been a while since I was able to devote much time to this and as the Weather Underground service is still not accepting submissions it hasn't been a high priority. However, with the festive season upon us and some time available I sat down to look at things again.
The code I had written worked on my laptop but failed on the RaspberryPi :-( thinking about the differences between them an obvious line of investigation was the relative processing power. After writing a simpler version of the app I ran some time comparisons and found that while the RPi was significantly slower (as expected) it should still be fast enough.
While doing some more checking I found there to be an issue with how the async read was being done from the RTL-SDR device. Fixing this resulted in the RPi starting to process messages correctly :-)
After a lot of time I finally rewrote what I had into code that worked and uploaded it to github. Perhaps it will help someone else? My understanding of how RF works is limited and I have little doubt my code can be significantly improved, but it seems to work. Improvements are very welcome!
It seems to be working for me and so the next step is to write a small script to grab the data and create a web page so we can view the data until Weather Underground get their act together.
I also need to add the ability to get some additional data I would like, starting with atmospheric pressure and possibly including soil temperature. Suggestions for doing this welcome :-)