The team at Eschelle Inconnue wanted to “trace a sound cartography of Islam” in Marseilles, France, so they came up with a clever little GPS walking tour powered by an Arduino, MP3 playback module, and a surface transducer speaker.

The team used a Processing app to define geographic areas where each MP3 file would play. An Arduino on the build queries a GPS module and selects the audio file from an MP3 playback module. This isn’t uncommon, and a lot of large outdoor museums (think battlefields) have similar setups.

Determining which audio to play at what location is fairly easy, but that’s not what makes this build special. Instead of simply hooking up a pair of headphones to the build, the team decided to use a surface speaker that turns just about any solid material into a speaker. From the writeup, this is supposed to, “diffuse sounds by giving the illusion to collect them, to listen to the words of the walls, the whisperings through the materials” but we think it’s just a great way to have several people listen to the same audio file at the same time.

After [Luke] built a suitcase mini-ITX rig for LAN parties he was left with one problem: he didn’t have any speakers and he didn’t want to use headphones. Not wanting to do something boring like a USB-powered speaker setup, he built a PVC Boombox.

Built around 3 inch PVC pipe, the boombox houses an off the shelf 15 W amplifier, bluetooth receiver, and charge controller. [Luke] found a deal on a dozen 1400mAh lithium ion batteries and despite the standard, “if you don’t know what you’re doing, don’t use lithium” trope commonly given as advice, he forged ahead anyway. [Luke] picked up a power converter that charges the batteries and provides some protection. The batteries are charged though wall power with a transformer and a huge cap scrounged from an ATX power supply.

[Luke] is pretty pleased with his boombox. Not only does it put out some decent quality sound, the battery life should be tremendous. It’s not a ground-up build, but we think it’s a pretty nice project. [Luke] will be taking the ‘boomtube’ to the Detroit Maker Faire next month, so if you see him make sure to say hi.

[Markus] on the DangerousPrototypes forum came up with a great little SID player.

The SID was (is?) the awesome sound generation chip inside the Commodore 64, and along with Game Boys and NESs laid the foundation for the chiptune scene. We’re happy to finally see a small SID player that doesn’t resort to SID emulation or a relatively huge MIDIbox.

The SID player itself is a shield on a CUI32 PIC dev board. The PIC32 emulates the 6510 and 6526 CPU and CIA chips found in the Commodore 64. A small USB memory stick stores the High Voltage SID Collection and the file system is navigated with an OLED screen. [Markus] says that the player draws 370 mA, so he runs it off a small wall wart. Still, we’re wondering if it’s possible to run this off of an SD card with a SwinSID so power draw can be reduced and a fully portable SID player can be realized.

We’ve got a touch of nostalgia for chiptune and demoscene music right now, so we’re going to listen to some [Nelly Furtado] [Janne Suni] right now, but you can check out the video demo [Markus] posted after the break.

Serial communications are a mainstay of digital computing. They don’t require much physical infrastructure and they exist in variations to fit almost any application. The behaviour of serial communications lines, varying from high to low voltage in a timed pattern, is analogous to a 1-bit DAC. Using a whole DAC for serial communication would be a waste in most cases, but the [RobotsEverywhere] team found an exception which you may have encountered already.

Since the audio output of the Android is accessible and addressable, [RobotsEverywhere] wrote source code to use the left and right channels as separate serial communication lines. This circumvents the need to bust into the device and muck about with the hardware which is great if you want a no-risk hack that allows communications to an RS232 port. Any hardware on which you can write to the DAC (and control the sampling rate) is a potential target.

There are some external electronics required to convert the audio signal to TTL, but it’s not very complicated–a couple of comparators and change. You can see it in action after the break.

As a bonus, when you’re done for the day you can plug in your headphones and listen to the soothing poetry of pulse waves all night long.

So you’re stuck in a boring class and you can’t fight off the urge to hack something, even your pencil, to pass the time. Maybe you are performing a live electronics show and you drop your synth down a flight of stairs and all that you are left with is a handful of components, a screw terminal block and a pencil. There are thousands, perhaps millions of these kinds of situations and for each one the answer is the solderless drawdio clone by [Martin].

You may have seen the original Drawdio here before, a fun piece of technology that is simple enough to recreate. This latest approach would make an excellent introductory project for a hacking workshop seeing as the guide is straightforward and the lack of soldering would make logistics so much easier. The results are very similar to the original–check the video after the break.

[bunnie] has taken a few moments to show us how to turn our Chumby One into a 3g router. As it turns out, there is an easter egg that allows it to communicate with certain models of 3g dongles. There’s no GUI for this trick, so you’ll be doing most of your configuration via SSH. That shouldn’t be a problem for this crowd though. The Chumby One just got a lot more appealing.

Hard drive speakers aren’t anything new, but they have yet to be done very professionally. Most hard drive speaker hacks are awesome, but aren’t meant to be a showpiece. [Oliver] took the opportunity to put together a set of 20GB drives and a custom-built acrylic case with a horizontal VU meter up front. The project is well-photographed and documented and can be recreated without the use of laser cutters or other expensive tools. The only thing it’s missing is an iPod dock!

Related: Giant bulb VU meter

[Moldover] decided to change up the way CDs are packaged for his album release. Yes, you still get a CD with some pretty sweet music, but the case can also play sounds. He custom printed a circuit board containing some LEDs, buttons, photoresistors, and what looks to be a piezo transducer which all combine to produce a strange whine like noise. But with the included headphone jack, he shows it can be used to produce some very interesting music – reminds us of circuit bending.

[Thanks Ferdinand]

Western Digital recently released a media player that attaches to your TV and allows you to play HD media straight from an external USB drive to the television. With a price point of about $100, it’s strange that the device hasn’t made more of a stir in the consumer electronics market. Of course, if it exists, someone will hack it, though. Clever hardware and software hackers have already managed to get an alternative firmware running on the device, allowing for packages like a web server, RSS reader, Apple trailer viewer, and other linux-based packages. It’s good to see a device with so many software mods so early into production.

Related: OpenPogo, an alternative to Pogoplug software

[Edo] wrote in to show us how he added RDS decoding to a radio made in 1957. RDS or Radio Data System is a protocol for data transmission. This allows date, time, artist info, and more to be broadcast along with the music. Its a nice feature that many new cars come with from the factory. [Edo] wanted to add it to his old radio though. He kept the radio stock looking, choosing to use an external LCD to display the data. He has posted the information on where to splice in to add this unit to pretty much any FM radio as well as posting the schematics and source code for the unit itself. Look at the very bottom of the page for the download link, its a bit hidden with the advertisements.

[Graham] bought a new stereo for his Peugeot 406. Unfortunately, the built in radio controls in his steering wheel didn’t interface directly with the head unit, but rather with the vehicle itself. His solution was to build a device to decode the button presses and send them to the head unit in the appropriate fashion. All source code and schematics are available on his site. He states that this should work on any PSA/Renault vehicle with a 125Kb VAN bus. We’re curious how similar some of the American systems are. We have seen something similar where someone wanted to control their Zune from the steering wheel.

The new Palm Pre cellphone has a “media sync” feature which lets the device sync with iTunes in a fashion identical to an iPod. Last week [Jon Lech Johansen] speculated that this was not done in cooperation with Apple and that Palm was spoofing the iPod’s USB controller. This was confirmed today when a tipster sent him a screenshot of what the device reports in both standard and media sync modes. The Palm Pre reports its Product ID as iPod and Vendor ID as Apple with a few other changes. [Jon] notes that it doesn’t change the root USB node, so Apple should be able to block this behavior with an iTunes update. With Palm already pulling tricks like this presumably through software we wonder if this will become a full-on arms race.

[Matt] wrote in to tell us about this project. He plans on travelling with his MSI Wind and wanted better audio recording capabilities. He decided to install an additional microphone and a preamp. He made a custom preamp and wired it directly to the motherboard. The microphone was then mounted in the laptop screen. The second microphone is placed opposite of the first, about 18cm apart which [Matt] claims gives it a binaural effect. We think that this might just classify as stereo though. Wouldn’t you have to seperate them with a barrier or dampening device for binaural? It doesn’t really matter though, stereo mics are a great addition to the MSI Wind, and he did it very well. He does point out that it picks up a lot of noise though. There’s always room for improvement.

Many people find themselves frustrated when working with headphones. The tiny coated wire can be a real pain to work with. They are so very very small, and usually coated.  We generally just end up doing a quick “sand and tape” which just isn’t very high quality.  [Alex] sent in some tips that can really help you get those repairs or modifications going.

For their final project in ECE 4760 at Cornell, [Christina] and [Joe] made a small single octave keyboard using LEDs as the input. They used a total of 63 LEDs to make the keys. Each key consists of 9 LEDs, with the center one acting as a sensor. When you lay your finger on it, the light reflects off of your finger and is picked up by the center LED. An ATMega 664 runs custom code to play a sound. You can find out more details about the construction as well as download the source code on the site. You can also download an example movie of it in action ( 7MB .mp4)