As a private pilot, it’s important to know the weather conditions before taking to the skies. In particular, strong winds and low visibility can be hazardous to flying. There’s a standard way to represent visibility and cloud ceilings on aviation maps: Green represents good, VFR (Visual Flight Rules) conditions, while blue, red, and magenta represent progressively poorer weather.
Normally you’d check a website for this information, but what’s more fun and easy to check than a physical chart with LEDs representing flight conditions at nearby airports?
Inspired by and building off the great build instructions and open source software from Philip Rueker’s blog post, I created my own version using a printed chart, individually-addressable RGB LEDs, and a Raspberry Pi.
I rewrote Philip’s code with an event loop to support user-initiated actions and to dynamically adjust LED brightness based on ambient light detected by a photoresistor. I also added a wind animation to oscillate the LEDs’ brightness. It uses a cosine function with randomly varied amplitude and frequency based on wind speeds, and a basic probabilistic state machine for wind gusts to simulate the manner in which a candle’s flame flickers in the wind.
The result is a useful map and a cool conversation piece at which I can glance to instantly get a sense of winds, visibility, and cloud ceilings at airports in the Bay Area and its surroundings.