Monitoring a sick bird using the Raspberry Pi


[Jorge Rancé] was nursing a sick bird back to health. He found it on the street with a broken leg, which required a mini plaster cast for it to heal correctly. But felt bad when leaving the house for long periods. He grabbed some simple hardware and put his mind at easy by building an Internet connected bird monitoring system. It’s really just an excuse to play around with his Raspberry Pi, but who can blame him?

A webcam adds video monitoring using the Linux software called “motion” to stream the video. This is the same package we use with our cats when we travel; it provides a continuous live stream but can also save recordings whenever motion is detected. He added a USB temperature sensor and attached a water level sensor to the GPIO header. These are automatically harvested — along with a still image from the webcam — and tweeted once per hour using a bash script. He just needs to work out automatic food and water dispensing and he never needs to return home! Bird seed shouldn’t be any harder to dish out than fish food, right?

A variable capacitor made from junk


[Jezan] decided to introduce his son to electronics by building a small crystal radio. These crystal sets have been around for a long time, and make for a great beginner electronics project, but some of the required parts are a little hard to come by. The most difficult to source part for these radios is a variable capacitor, and not finding one in his parts bin, [Jezan] decided to make his own.

This variable capacitor comes directly from a piece of 1.5 mm thick aluminum sheet. Instead of fancy CNC machines, power tools, or even a pair of tin snips, [Jezan] cut the rotors and stators for his variable capacitors with a pair of scissors. The center hole was punched out with a piece of sharpened pipe, and all the pieces were filed down and sanded for a perfect finish.

Considering the variable caps you can get your hands on are either rare or very old, this looks like a great afternoon project for the budding electronics wizard or radio enthusiast. [Jezan]‘s craftsmanship is incredible as well and the finished part looks like it came off an assembly line.

Building a bike for 100 miles per hour



As a kid, [Tom] followed all the automotive land speed record attempts on the Bonneville Salt Flats. The cars used in these attempts were all built by guys in their garages, and as a bicycle frame builder, [Tom] is keenly aware of the land speed record for bikes. One thought leads to another, and [Tom] decided he would see how fast one of his frames could go.

Aside from a gigantic gear for his custom bike, [Tom] also needed a little help from a friend. The current land speed record on a bicycle was done by drafting behind a drag racer. [Tom] doesn’t have a drag racer, or a wide expanse of flat open ground in his native England, so he did the next best thing: drafting behind a Ford Zephyr on an abandoned WWII airstrip.

On the runway, [Tom] was able to get his bike up to 80 miles an hour. Wanting to see how fast he could go in ideal conditions, the bike was taken to the garage, put on a pair of rollers, and measured as it was brought up to speed. With a lot of effort, [Tom] was able to get up to 102 miles per hour, incredibly fast for something powered by human muscle.