It looks like a consumer good, but this PBX server blade was built by [Benoit Frigon] over the last couple of years. It brings multiple telephone extensions to his home service.
The device runs Asterisk open source PBX software. Because it will be on all the time he wanted something that doesn’t draw a lot of power. The 500 Mhz system seen on the left has just a half a gig of ram. It’s enough to do the job and at 10 Watts it’s not going to break the bank when it comes to paying the electric bills. The board in the middle is used to interface the analog handsets with the land line. From the look of it he’s got it rigged for two extensions.
That’s all somewhat par for the course with PBX rigs, but the enclosure is where he really shines. [Benoit] used 22 gauge aluminum sheet to fabricate the enclosure which is designed to blend in with the rest of his home’s rack mount hardware. To provide control at the rack he added his own LCD and touch-sensitive button interface to the front of the case based on a PIC 18F2520. The system can also be accessed via the web thanks to a custom interface he coded.
[Markus] built his own reverse geocache puzzle box but on a smaller scale than the original. His is based around a PIC 18F2520 and powered by two AAA batteries. The user interface includes one button, a 16×2 character LCD, and a piezo speaker. The box unlocks itself when the GPS module inside detects the proper location on the globe. There is also a secret code that can be tapped on the button to unlock the box prematurely, and another to show the locations in which the user attempted to open the box. This build doesn’t leave much room for a payload, but [Markus] did a great job designing the board and making the components fit as efficiently as possible.
[Andrew] built this pong clock over the span of a couple of days. The PIC 18f2520 he used can serve as a real time clock with the addition of an external clock crystal. His project proves the usefulness of an oscilloscope as poor board layout caused interference in the crystal connections, something difficult to troubleshoot without this handy lab tool.
Pong clocks have been quite popular. This one is nice because it’s easy to throw together now that [Andrew’s] done the coding work for you. Written in assembly, reading and understanding his code might be a good exercise if your low-level language skills are lacking.