Host of the Soldersmoke podcast, [Bill Meara], contributed this guest post.
WSPR is a new communications protocol written by radio amateur and Nobel Prize winner [Joe Taylor]. Like the very slow QRSS system described in a previous post, WSPR (Weak Signal Propagation Reporter) trades speed for bandwidth and allows for the reception of signals that are far below the level of radio noise. WSPR takes “low and slow” communications several important steps ahead, featuring strong error correction, high reliability, and (and this is really fun part) the automatic uploading (via the net) of reception reports — [Taylor]’s WSPR web page constantly gathers reports and produces near real-time Google maps of showing who is hearing who. The WSPR mode is very hack-able: [Bill Meara] is running a 20 milliwatt homebrew transmitter from Rome, Italy that features an audio amplifier from a defunct computer speaker pictured below. This contraption recently crossed the Atlantic and was picked up by the Princeton, New Jersey receiving station of WSPR’s esteemed creator, [Joe Taylor]. Continue reading “WSPRing across the Atlantic”
Ever wanted to make your own LED? You might be tempted to after reading how easy it is. No, this won’t really be a practical LED that you would use to light a project, but it is very cool anyway. [Michael] picked up a box of Moissanite, or Silicon Carbide, on eBay for roughly $1. Making the LED is as easy as putting your positive lead to the crystal and touching it with a sewing needle attached to a negative lead. He has tips on how to get the best results as well as a little bit of history of LEDs on the site.
[Tom] sent us a link to this very professionally done project. He built a bike light that is a 540 lumen Luxeon light with a custom case. The LED, Lens, and driver were purchased first. Everything else was designed around it. The design is compact and good looking. You can download the CAD files on the site if you want to make your own. He is using an Atmel AVR ATTiny13 to control brightness.
PSP firmware 5.03 has been hacked by Team Typhoon. This allows you to run custom code on the PSP by taking advantage of the tiff exploit. You’ll have to wait to download the hack though, they haven’t released it yet. This means those of you still on 5.02 or still using the little blue tool will be able to upgrade soon.
[Daniel] had to have runaway in his mind when he built this coil gun. It’s hand held, holds 14 42 gram rounds and can propel them at speeds of 110km/h. Of course when it is battery powered, you have a 90 second warm up time between shots. It can also be used while plugged into a wall socket, which reduces the charge time to roughly 3 seconds. Great job [Daniel].