A Suitcase Full Of Tunes

November 22, 2012 by Mike Szczys 12 Comments

Take the party with you by building your own boomcase. It’s an amplifier and set of speakers built into luggage. It uses an audio jack to connect to your favorite music player, and with a bit of added protection — like grills for those speakers — it could still be gently used to transport your wardrobe.

A 1960’s suitcase was mutilated for this build. [Jay] must have already had it on hand because combined with some used parts he claims to have only spent $50 total. After trying out a few different speaker orientations on a piece of cardboard he covered the outside of the case in blue painter’s tape and started cutting holes. The amp he chose has a nice face plate which happens to fit nicely on the top side of the case. For now he’s powering it with a 10,000 mAh (ie: 10 Ah) portable device recharging battery. But as you can hear in the demo after the break this seems to have no problem supplying the system with enough power.

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Upgrading A Voice Recorder With A Hex Editor

November 10, 2012 by Brian Benchoff 62 Comments

[Alex] just bought a really nice TEAC VR-20 audio recorder, a very capable recorder perfect for recording your thoughts or just making concert bootlegs. This model was recently replaced by the Tascam DR-08 audio recorder. It’s essentially the same thing, but the Tascam unit can record at 96kHz, whereas the TEAC can only record at 48kHz. [Alex] figured out a way to upgrade his less capable but cheaper VR-20 to record at a higher bit rate with just a simple firmware hack.

The mod began by downloading the firmware for both the TEAC VR-20 and the Tascam DR-08. Both of these sets of firmware were exactly the same size, and after downloading a hex editor, [Alex] found a huge difference in the first 20 bytes of the firmware – the portion that tells the microcontrollers what it actually is.

The solution to improving the bitrate for the TEAC VR-20 was as simple as copying the first 20 bytes from the TEAC firmware over to the first 20 bytes of the Tascam firmware. After that, it’s a simple matter of upgrading his TEAC and getting the ability to record at 96kHz.

A very, very simple hack that’s really just flipping a few bits. Not bad for a two-fold improvement in the recording capability of a handheld audio recorder.

Hardsync – DDR Reimagined For The C64

November 9, 2012 by Jeremy Cook 10 Comments

For those of you that like to play dance games, but [DDR] for the [PS2] uses too modern hardware for your tastes, [Hardsync] may be for you. Although the chiptune-style music coming out of the [C64] may not appeal to everyone, one would have to imagine that a game like this could have been a huge hit 30 years ago.

As for the hardware itself, it does indeed use one PS2 element, the dance mat. It’s hooked into one of the C64 joystick ports. In this case, the cable was cut, but it would also be possible to make a non-destructive adapter for it so as not to interfere with any future PS2 fun.

The program is made so that fellow retro-dancers can make their own songs. Each song is a discreet file, and can be reconfigured to your own personal mix. Be sure to check out the video after the break of this old-school dance machine in use after the break! Continue reading “Hardsync – DDR Reimagined For The C64” →

Arduino MP3 Jukebox

November 7, 2012 by Mike Szczys 14 Comments

Here’s an inexpensive Arduino-based MP3 Jukebox (translated) which [Jose Daniel Herrera] put together.

He spent some time making sure that it looked great sitting on a shelf with his other audio equipment. This started with a wooden box which is some reused packaging. We’re not familiar with the ‘iNFUSiONES’ product; perhaps it’s tea or tobacco? At any rate, to this he added a custom face plate to host the character LCD, rotary encoder, two buttons, and to act as a grill for the two speakers.

The speakers and their accompanying amplifier circuitry were pulled from a portable speaker set. He combined them with a VS1002d MP3 decoder module, SD card breakout board, and the Arduino itself. In addition to the overview post linked above, there is also a collection of assembly photos, and a post discussing the way he arranged the code for the control systems (translated). See and hear the unit in action in the clip after the break.

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Collection Of Nixie Bar Graphs Bump To The Beat

November 5, 2012 by Mike Szczys 10 Comments

This VU meter uses Nixie tubes as the display. There are a total of fourteen IN-13 bar graph tubes that map out the audio spectrum. The build uses purely hardware for the display; no microcontroller processing, or dedicated VU-meter chips were used.

Input begins with a dual Op-Amp along with a pair of potentiometers which allow the left and right channels to be balanced. Both channels are then each split into seven signals, which explains the layout of tubes seen above. Each signal is then fed through a voltage divider to envelope the output between 0V and 6V. There is also a low-pass filter to handle sudden volume spikes which don’t work well with the nixies. But as shown in the video after the break, all that work has paid off. Thr clip gives us a look at the green protoboards which host all of this filtering hardware. You’ll want to turn the volume down for the first couple of demonstrations which use a sweep to test the system.

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One-button Audiobook Player Made From A Raspberry Pi

November 1, 2012 by Mike Szczys 35 Comments

[Michael Clemens] was looking for gifts for his Grandmother’s 90th Birthday. She is visually impaired and loves to be able to listen to audiobooks. The problem is that she doesn’t really get the hang of using electronics. He made things easy by building her a one-button audiobook player.

The Raspberry Pi board is a perfect solution for this project. It’s cheap, it has an audio port, it has storage for the books on the system SD card, and it runs Linux. The last part is key as it made things very simple when [Michael] started pulling together the various components.

When the RPi is powered up it drops immediately into a Python script which loads the audio track and places the music player daemon in pause. The yellow button seen above works as a play/pause button when clicked. If the listener misses something she can hold the button for more than four seconds to go back one track. Loading new books is easy too. [Michael] copies the files onto a thumb drive with a special volume label. When plugged into the RPi USB port the script automatically copies the book and starts playing when the drive is removed. He included a video demo on his project page linked above.

Hacking An Old Radar Gun To Interface With A Laptop

November 1, 2012 by Mike Szczys 24 Comments

[Gregory Charvat] decided to see what he could do with this old Police radar gun. It is an X-band device that broadcasts continuous waves and measures the Doppler shift as they echo back. He cracked it open to see if he could interface the output with a computer.

After a little poking around he’s able to get it connected to a 12V feed from his bench supply, and to monitor the output with an oscilloscope. He established that it draws about 0.5A in current he built a companion board which uses AA batteries for power, and provides an audio output which can be plugged into his laptop’s audio-in jack. This technique makes reading the device as easy as recording some audio. From there a bit of simple signal processing lets him graph the incoming measurement.

In the video after the break you’ll see his inspection of the hardware. After making his alterations he takes it into the field, measuring several cars, a few birds, and himself jogging.

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