We mentioned Pulse Width Modulation (PWM) when talking about [sprite_tm]’s marquee control. It’s a method of power control. While [sprite_tm] did it in software, [Afroman] sent along a very straight forward introduction to PWM using just a 555. Check out his video for coverage of this fundamental electrical design technique.
[Rory Hyde] and [Scott Mitchell] are exploring several projects that add more information to public spaces. The first is the Spoke-o-dometer a persistence of vision device that can display bicycle speed and distance traveled. To develop the device, they first bought a few POV kits to test out. They decided to build their version using an Arduino. Once they had the display proof of concept working, they added a hall effect sensor like the SpokePOV so they could determine speed and orient the display. Check out their project site for plenty of example code and development details.
[via ladyada]
Not all hard drives fail the same way. DataCent, a data recovery service based in Canada, has an impressive archive of failing hard drive sounds. If you’re ever in doubt about whether your hard drive needs help, this is your guide. From bad heads to stuck spindles, bad hard drives click, grind, hum, and scratch. It’s almost musical in its regularity. Who will be the first person to string of these samples together into a ringtone or techno song.
[photo: Boja]
[via MetaFilter]
[vimeo 2245777]
After being inspired by our previous posts on a microcontroller-powered missile launcher and the wireless fireworks controller, [Adam] at Additronics.com decided to build his own microcontroller launcher. He combined elements from each of the prior projects, and included some of the advice from the Hack a Day comments. His multi-rocket/fireworks launcher is configured with an Arduino Diecimila, and requires a whole boatload of batteries. [Adam] claims there’ll be another video at New Year’s of the microcontroller in action, which we’re definitely looking forward to watching.
In a previous job, [sprite_tm] was responsible for wrangling many different LED text ad marquees. The hardware was fairly simple and he always figured they could be pushed much further with a little work. He recently acquired ten 32×16 LED displays a decided to see what he could do with them. By the end of the project, he had full motion video running on the display. This is a great project to read up on if you’ve ever wondered about LED matrix displays. He starts by reverse engineering the electronics on the board. He then attached an ATmega88 to drive the display module. Multiple display modules were daisy chained together over serial. The article covers PWM control and refresh timing as well. Check out one of a few demo videos below. Continue reading “Overhauling LED Marquees”
[Matthew] sent in this slick project where he made a Mac pro Ultra Mini. He received a MacBook that had been killed by water. He took it apart, re-soldered some connections and was able to get enough of it working to be a decent multimedia machine for his tv. To make it look nicer, he found an external drive case that looks like a tiny Mac Pro. After a little bit of grinding, cutting, and zip tying he managed to get all the pieces inside the case. We’re always happy to see hardware salvaged, and to see it transformed to a fantastic looking useful machine is a bonus. Good job [Matthew].
[youtube=http://www.youtube.com/watch?v=2E8vsQB4pug]
Scratch input allows us to use solid surfaces as an input devices by capturing the sounds they produce. Using a stethoscope and a high pass filter, they capture the unique sounds of specific gestures. Custom software then translates this to actions for applications. The video shows some really cool stuff, like turning an entire wall into an input device. It goes around corners and past doorways. They even talk about potential using your clothes to capture input.
[via Procrastineering]
