Planet Arduino

Public transit can be a wonderful thing. It can also be annoying if the trains are running behind schedule. These days, many public transit systems are connected to the Internet. This means you can check if your train will be on time at any moment using a computer or smart phone. [Christoph] wanted to take this concept one step further for the Devlol hackerspace is Linz, Austria, so he built himself an electronic tracking system (Google translate).

[Christoph] started with a printed paper map of the train system. This was placed inside what began as an ordinary picture frame. Then, [Christoph] strung together a series of BulletPixel2 LEDs in parallel. The BulletPixel2 LEDs are 8mm tri-color LEDs that also contain a small controller chip. This allows them to be controlled serially using just one wire. It’s similar to having an RGB LED strip, minus the actual strip. [Christoph] used 50 LEDs when all was said and done. The LEDs were mounted into the photo frame along the three main train lines; red, green, and blue. The color of the LED obviously corresponds to the color of the train line.

The train location data is pulled from the Internet using a Raspberry Pi. The information must be pulled constantly in order to keep the map accurate and up to date. The Raspberry Pi then communicates with an Arduino Uno, which is used to actually control the string of LEDs. The electronics can all be hidden behind the photo frame, out of sight. The final product is a slick “radar” for the local train system.

Before beginning his day, [Richard] needs to decide whether he should ride his bike to work or take the London tube. All the information to make that decision is available on the Internet – the current weather report, and the status of the subway lines and stations he’d be taking. The problem, though, is all these pieces of information are spread out in multiple places. [Richard]‘s solution to this was to make a bicycle barometer that pulls data from these places and makes the decision to ride a bike or the tube for him.

[Richard]‘s barometer is built around a nanode and an old clock he found at a flea market. The nanode queries the UK’s weather bureau and the London underground’s line and station status. All the variables under consideration are weighted; if it’s snowing, the output is much more likely to decide on the tube than if there was a slight drizzle.

It’s a really cool build that certainly makes a great use of the publicly accessible APIs made available by the London underground. You can check out a video of the barometer after the break.