Amplifier Built Inside A 9v Battery

February 3, 2010 by Mike Szczys 42 Comments

It’s pretty creative to use a 9v battery as an enclosure. That’s what [Osgeld] did when building this amplifier. There are several advantages; they’re easy to find, it keeps a bit of the dead battery out of the landfill, and this method provides a built-in connector for a 9v power source. In this case the circuit is built around a LM386 audio amplifier. It’s glued to the back of a potentiometer and wired up with the other components for a package smaller than a quarter. A stereo jack reside in the side of the battery case with a cable and alligator clips for connection with a speaker. Now the amp can be quickly connect to any 4-8 ohm speaker.

Foil Impressioning Defeats Security Locks

February 3, 2010 by Mike Szczys 32 Comments

Apparently it’s been around for fifteen years but using foil impressions to pick locks is new to us. This is similar to using bump keys but it works on locks that are supposedly much more secure. This method uses a heavy gauge aluminum foil to grab and hold the pins in the correct place for the lock to be turned. The foil is folded over and slits are cut where each pin will fall. It is then inserted into a lock on a tool shaped like a key blank. Jiggle the tool for a bit and the cylinder will turn. This just reminds us that we’re much more dependent on the good will of our fellow citizens to not steal our stuff, rather than the deterrent that a lock provides.

We’ve embedded a detail and fascinating demonstration of this method after the break. The materials in the video are from a Chinese-made kit. We’re not sure where you find these types of locks, but we don’t feel any less secure since our keys could be obtained from a distance anyway.

Update: Video now embedded after the break. The link is down but you can try the Google Cache version.

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USB HDD Enclosure To DVD Connector

February 2, 2010 by Mike Szczys 123 Comments

This is a “why didn’t I think of that?” idea. [Alec] needed a way to connect an IDE DVD drive using USB. Rather than order a connector he pulled the circuit board out of an old USB hard drive enclosure and connected to his DVD drive. Bang, recognized and running.

This will prove extremely handy if you have a netbook without an optical drive. We’ve used Unetbootin to move Linux ISO images to a thumb drive in the past. In addition to getting around the lack of an optical drive, this saves burning the data to a piece of plastic. But, you should be able to use this with a Leopard retail DVD instead of a 16GB thumb drive for a Hackintosh conversion. That means you could install Leopard on a netbook without needing a Mac to transfer the disk image to your thumb drive first.

Our Favorite XBOX To HTPC Hacks

February 2, 2010 by Mike Szczys 17 Comments

Let’s face it, the original Xbox is ugly. It might have looked cool when it first came out but now most would be embarrassed to display that old beast with the rest of their entertainment hardware. This is unfortunate because the old girl still has some life in her. If you have tools, time, and talent you can give the box a facelift and bring it back to see the light of day. We’ve got six of our favorite Xbox to Home Theater PC hacks after the break to inspire you.

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Beginner Concepts: 555 Push Button Toggle

February 2, 2010 by Mike Szczys 29 Comments

PIC, AVR, and Arduino are ubiquitous in projects these days and a lot of the time it’s easy to over-complicate things with their use. In this case, [Tod] wanted to use a momentary tactile switch to turn something on and off. Instead of going with a microcontroller he built the circuit around a 555 timer. What he really needed in this case is a flip-flop but lacking a chip for that he went with the 555 because it has one built-in. Three resistors and a capacitor later he’s in business, adding another resistor and a transistor to deal with the load switching. We’ve embedded video of the circuit controlling an LED after the break. This IC ends up in a lot of projects so dig through your parts bin and give this circuit a try.

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Game Controllers Using USB Host Shield

February 1, 2010 by Mike Szczys 21 Comments

[I-Bot] has put together some libraries that make it easy to use gaming controllers with an Arduino. They interface through the USB host shield. This means that PS3 controllers connect via USB through a cable or a dongle. With the Wii remote things get a little more interesting. A Bluetooth dongle is used to make the connection wirelessly. What we have here is a cheap and easy way to add Bluetooth connectivity to your projects either through the USB Host shield, or by building your own hardware with the schematics and code that are available from Circuits@Home. There are several pages that walk you through the protocols using as well as a demonstration video you can see after the break. Continue reading “Game Controllers Using USB Host Shield” →

Android Audio-serial Connection

February 1, 2010 by Mike Szczys 15 Comments

This seems like something of a throwback hack. [WilinNeofoxx] has built an audio modem interface for use with his Android phone. A program running on the Android device takes the accelerometer data and converts it into a 9600bps audio signal, kind of like a dial-up modem. His custom circuit board takes that sound in through the headphone jack and demodulates it for use on the serial port of a PC. This connection to controls a flight simulator using the G1‘s motion sensors. In the video at the bottom of his post he unplugs the audio cable for a few seconds and you can hear the audio datastream coming from the phone. It’s pretty annoying so you might want to turn down those speakers before viewing it.