Posts Tagged ‘rgb led’


Last night I finished throwing together a workable version of the Weatherball, currently displaying a color code at the end of my flagpole to indicate whether tomorrow holds any interesting weather. Apparently cities and radio stations have been doing it since the 1950s, but now I have my own! The data is grabbed from the NOAA’s National Digital Forecast Database server (XML) using a quick C++ program, and currently acts on five variables: chance of precipitation, chance of hail, chance of tornado, chance of extreme wind, and cloud cover percentage. Any ‘interesting’ values in these fields are evaluated in order of decreasing importance (beginning with hail/tornadoes), and the most significant weather condition is sent to the das Blinkenlichten node in the ball at the end of the flagpole.

In the spirit of virtually all known Weatherballs to date, here is a not-very-catchy jingle expressing the color code:

If the weather ball is yellow/green, the sun’s expected to be seen
If the weather ball is gray, anticipate a cloudy day
If the weather ball is blue, it probably will sprinkle too
If the weather ball’s maroon, be prepared for a typhoon
And if the weather ball is red, forget the beach – head for the basement instead!

(And if the weather ball draws half an amp, the electronics have gotten damp – the Blinkenlicht inside the ball has been outside for nearly a year (just waiting for me to get around to writing the software) and seems to still work fine, but I really should weatherproof that sucker.)

Weatherball showing no interesting weather for tomorrow (yellow-green). Know what it needs now? More Power!

Here are the main parts – the ball is supposed to be a curtain rod capper.

The program to fetch weather reports from the interwebs and drive the ball

The DON’T PANIC flag* (Hitchhikers Guide reference; the house number is 42) is showing a bit of weathering, but is still intact. The flag pole is a piece of lightweight enameled metal rod from the big-box hardware store, intended for hanging stuff in closets. The bubbly clear ball on the end is a decorative curtain-rod endcap from Ikea. A set screw on the side allows it to be attached to rods of various diameters. The exposed clear plastic extends through the inner diameter of the endcap some on the inside, allowing the LED node placed in the base to light up the ball (though not brightly enough for my tastes; may beef it up a bit later). The material can also be drilled out to embed the LED further into the ball, if desired.

* If McCain gets elected, it will be replaced by a bright red PANIC! flag, and the weatherball recoded to display the current terrist alert level. It will operate briefly in this manner while I search for a homebuyer and a cheap one-way ticket to Canada…