I have been using anAcuRite Digital Vertical Weather Forecaster with Indoor/Outdoor Temperature, Humidity, and Date and Time. The outside temperature thermometer with this unit wirelessly relays temperature and humidity measurements over a 433 MHz wireless frequency to the indoor weather station. I began to wonder if I could use an RTL-SDR to receive/parse that information and do some interesting things with it.
I did some searching and found rtl_433. This program works with an RTL-SDR and parses a number of types of data packets - including those transmitted by my AcuRite station.
After following the simple install directions, I was able to use this command to show the data from my weather station:
rtl_433 -F json -E quit -R 40 -C customary 2>/dev/null | jq .
So that was step one (and what I perceived as the hardest part) covered. Then I decided I wanted to see what I could do with that data.
Given my APRS interest, adding that data to my small fill-in digi seemed like a no-brainer. I use Direwolf to run my digi and I found that I can use the wxnow.txt formatted files with it to add the weather data to my beacons. So then I needed a way to transform the output from the rtl_433 to the wxnow.txt format.
More research lead me to Weewx which can be configured to both read from rtl_433 and generate files in the wxnow.txt format; specifically, weewx-sdr bridges the gap between rtl_4300 and weewx and weewx-cwxn is an extension to weewx that creates a wxnow.txt file.
All that was left was a little configuration and my weather station is on the air!
The data can be viewed on my WeeWX weather page