I just purchased one of these from my local Costco store for CAD$80: http://www.acurite.com/8-professional-digital-weather-station-with-weather-ticker-pc-connect-01025.html. The outdoor sensor reads temperature, humidity, wind speed, wind direction, and rain, and communicates this data wirelessly to the base-station in the house. The system also figures out dew point, barometric pressure, wind chill, heat index, and some other things that I can't think of at the moment. The outdoor sensor even has a little solar panel to extend the battery life. You can see the output from my weather station here: http://www.wunderground.com/weatherstation/WXDailyHistory.asp?ID=IBCSURRE23
The system is capable of communicating with a computer, and regularly uploading the collected data to Acu-rite's website, and from there capable of uploading that information to Wunderground.com.
Overall, this seems to work great. There are a couple of glitches in the data sent to wunderground.com (no hourly rainfall data, for example) that apparently Acu-rite is working on. However, there seems to be no published timeline for the fix. There are also rumblings that they may expose parts of their API, but again no details on this either.
Now the big question is, what would it take to listen to the RF transmissions from the 5-in-1 weather with an mbed? This might be the way to go for anyone interested in a reasonably accurate collection of weather sensors IF we can figure out how to snoop on the transmissions and interpret their data.
Chris
Has anyone worked with one of these Sparkfun weather sensor setups or know of some other low cost options?
http://www.sparkfun.com/products/8942
It includes an anemometer, wind vane, and rain gauge. Also has mounting hardware with RJ11 connections and cables to the sensors.
The anemometer uses a reed switch, so simple frequency detection can be used to measure wind speed. The wind vane uses a potentiometer (or eight switches?) to detect wind direction. The rain gauge acts as a switch that closes at measured increments when the cup fills and dumps out the rain.
It has some documentation at http://www.sparkfun.com/datasheets/Sensors/Weather/Weather%20Sensor%20Assembly..pdf . Price is about the same as an mbed. I also considered hacking a low-cost home weather station setup, but they don't have documentation on sensors. Also found some RJ11 breakout boards at http://www.gravitech.us/rjbrbo1.html that would come in handy.