[erck] built an iPod charger inside of a 9V battery. I’m actually more interested in the two reference links he included with the project. The first is Sijosae’s gallery of headphone amps. He’s built over 130, there are other projects included as well. The second is Ted’s iPod Battery Pack which links to almost every DIY and commercial iPod charger on the web.
Master modder ZapWizard has completed work on version 3 of his home built powder coating gun. Powder coat is applied using air pressure to blow negatively charged thermoplastic particles onto a grounded metal surface. The metal part is then baked to make a hard finish. ZapWizard’s gun uses an air pistol with regulator at the bottom operating at 15 PSI. The powder is held in an acrylic kitchen canister with a reinforced seal. The final element is an ionizer element placed in front of the discharge nozzle. Version 2 had a trigger operated switch for the ionizer, but that was replaced with just a simple toggle.
I’m amazed at how many people are willing to chop up their brand new toys. Take [edahc]’s brand new MacBook Pro. He decided to mount a Sony Puppy FIU-600 fingerprint scanner in the case. The device is powered directly from the DC board. I think the MacBook Pro may actually lend itself more to these types of modifications than most laptops because of the large flat metal surfaces on the case. More so than say your standard lumpy plastic Dell.
Eddie has an interesting writeup about his experience playing around with echo location. He uses a cheap computer speaker and microphone for all of the measurements. The program he wrote generates a sweeping chirp from 5-20kHz in the space of 4.5 milliseconds. Eddie knows what a perfect echo would look like so he can compare the measured values to the theoretical to determine the distance. For his final test he moved the box while it took 150 measurements. This data generated a parabola showing where the object was in the room. Have a look at his site for more details and his code if you are interested.
A Radiosonde is an inexpensive sensor package that’s intended to be used with a weather balloon for atmospheric measurements. The device transmits data in the 403 MHz band after being launched and they usually aren’t recovered after use. You can pick them up for very little money on eBay so [Nick] thought they might work well as a low cost GPS tracker. Unfortunately the Radiosonde doesn’t transmit standard NMEA GPS data, but GPS doppler measurements. It’s hard to determine what those are actually useful for. Nick did find one other paper documenting an unsuccessful attempt which he has posted to his site. So now Nick is looking for some help either making the data more useful or coming up with a functional device that’s just as inexpensive. Anyone got any leads?
With FON now selling their “social routers” for $5 a piece it seems like a good time to mention Hack-A-Day reader [Steve Anderson]’s previous FON hacking experience. By purchasing one of FON’s subsidized routers you agree to participate in their network for at least one year. Steve had a look at the patched OpenWRT firmware FON uses and found the heartbeat system they use to monitor compliance. He then swapped out the firmware and spoofed the heartbeat with a cron job. This hack is an ethical trade off: remove FON’s firmware and violate their terms of service or keep FON’s firmware which probably violates your ISP’s TOS. In related WRT54G news: you can now flash Linux onto v5 and v6 routers without hardware modification. So if you’re at all worried, just buy one for the regular price off the shelf.
[thanks bird603568 and fucter]
Hans Summers has an amazing collection of projects. His most popular project is the binary clock. It runs off of mains, uses a bunch of TTL logic chips and a binary counter. He has posted links to the many projects that have been derived from his original post. Warning: project uses LEDs. If the binary clock isn’t your thing he has lots of other clocks, radio, frequency counters, computer and other projects.
[thanks Alan Parekh]
