Should I bring an umbrella?
Living in Göteborg, Sweden means that many mornings you ask yourself the question "do I need an umbrella today?". To outsource more small decisions to computers I programmed a microprocessor that respond with activating a led if an umbrella is recommended.
The idea is very simple. The microprocessor reads the weather forecast from yr.no for the next 10 hours (which is about the time I expect to be away from home). If any of these hours include rain (more than a few mm) then light the led. Unlit led obviously means no rain.
How it works
Spark Core Breadboard Light Emitting Diode Resistor Usb cable for power supply
Weather forecast with php and yr.no
I run a php script which gets the next forecast from yr.no. It is published at http://sebastiannilsson.com/will-it-rain/and is relatively easy to use.
Find the city that you want the forecast for and copy the URL. For example, in Gothenburg is the http://www.yr.no/sted/Sverige/Västmanland/Kolbäck/or Kolbäck http://www.yr.no/sted/Sweden/the stra_GÃ ¶ taland/Gothenburg/ Go to http://sebastiannilsson.com/will-it-rain/index.php?debug = 1&threshold = 0.1&yr_url = Example: Forecast for Gothenburg with a threshold for rain in 0.5 mm looks like this: http://sebastiannilsson.com/will-it-rain/index.php?debug=1&threshold=0.5&yr_url=http://www.yr.no/sted/Sverige/V%C3%A4stra_G%C3%B6taland/G%C3%B6teborg/
Code on the microprocessor
Spark Core is a microprocessor that connects to Wifi. You upload your code to it over their cloud service.
Get a Spark Core or similar and connect it to wifi. Copy my code for the Spark Core. The only needed change is the variable for the url. Upload