If Nixies aren’t cool enough, maybe it’s time to step it up to magic eye tubes.
Magic eye tubes are, like Nixies and Dekatrons, display tubes. Unlike the alphanumeric characters of Nixies or rotating points of light in a Dekatron, Magic eye tubes are either bar graph or ‘Pac-Man’ displays that were used to show the signal strength of a radio station on very expensive radio sets.
After doing a few experiments with tubes, [sylvain] thought it would be cool to do something with magic eye tubes. He sourced eight vertical ‘bar graph’ magic eye tubes and built an audio spectrum analyzer.
One of the more difficult things to do was to compute the power levels for each frequency band. There are a few graphic equalizer ICs available, but [sylvian] decided to go the old-school, harder way by putting an FFT algorithm on an ATMega624.
An impressive piece of work that would look amazing next to a nice tube stereo system.
If you’ve checked out your favorite online retailer of absurdly inexpensive Chinese electronics, you’ll find a whole bunch of replacement parts. Phone parts are especially common, with high-resolution LCDs available for just a few dollars. There are also a few touchscreen kits – resistive touchscreen digitizers that can easily be read with a microcontroller. [Vinod] got his hands on one of these touchscreen digitizers, and with the help of an 8-pin micocontroller turned it into a Bluetooth trackpad.
The clear plastic touchpad is a relatively simple device. By reading a pair of analog values, it’s easy to find the coordinates of a finger or stylus on the touchpad. [Vinod] programmed an ATtiny13 to read these values and turn them in to x y coordinates, but he needed something useful to do with this data.
By connecting a small bluetooth module to his microcontroller, [Vinod] could send these coordinates to his computer. The result is a homebrew touchpad, able to move a cursor around, left and right click, and emulate a scroll wheel.
Continue reading “A Bluetooth trackpad from a resistive touchscreen”
The Internet lost a few great minds this week. [Aaron Swartz], confronted with an upcoming federal trial for his actions in downloading and releasing public domain academic articles from JSTOR, hanged himself this week. As one of the co-developers for RSS, the Creative Commons license, and slew of other works, [Aaron]’s legacy expanded the freedoms and possibilities of the most important human invention since the book.
Perhaps overshadowed in the news by [Aaron] is [Fabio Varesano], the man behind FreeIMU and Femtoduino. He died of a sudden heart attack at the much too young age of 28. The RC helicopter/plane/drone and HCI/physical computing communities lose a great mind with [Fabio]’s passing.
There is talk on the Dangerous Prototypes forum of continuing the development of FreeIMU, a project it seems [Fabio] worked on alone. We’d love to see someone pick up the reigns of the FreeIMU project, hopefully after doing a run of the current hardware and donating the proceeds to [Fabio]’s family.