Assembling a Mobile MP3 Player From Standard PC Hardware
As of this writing (June 2000), all commercially-available MP3 car audio solutions suck. Mainstream vendors
such as Kenwood
are finally beginning to offer decks capable of playing MP3 files stored on CD... but in reality, this feature
offers little additional storage capacity beyond a conventional 10-disc CD changer. Before you can hit the road
with an MP3 collection of any respectable size, you'll have to deal with startup vendors like UK-based
Empeg that bring time-honored retailing terms like "Coming soon" and "Out of
stock" to the Internet age. And you'll pay for the privilege, too. An Empeg head unit with 18 GB of
storage will set you back a cool U.S. $1,449.00, amp and speakers not included.
Here's a homebrew alternative to the inadequate, overpriced, and
sparsely-available MP3 autosound offerings on the market today. This system, which I've built and installed in two of my cars, has
a lot going for it:
- Cheap. Based on an ordinary AMD K6-2 350 MHz motherboard and minitower case, this system can be reproduced for less than $300 in additional components.
- Customizable. All software, from the user interface to the MP3 decoder, is modifiable and configurable. You don't have to suffer with Vendor X's idea of the right way to index and play MP3s.
(You don't even have to suffer with my idea of the right way to play MP3s, since the control software is Open Source!)
- Simple. Off-the-shelf components, such as a 300W power inverter, Sound Blaster AWE64, and FM wireless broadcaster, are used wherever possible, minimizing the amount of custom electronic work necessary.
- Great-sounding. With a good-quality PC sound card and a careful installation that's free of ground-loop noise, sound quality is limited primarily by the encoder choice and bit rate used to rip the MP3 files in your collection.
Of course, the downside is that some "sweat equity" is necessary to make it all happen. You'll need to be comfortable with the basics of
software and hardware hacking if you're interested in constructing this project or anything similar to it. Some soldering and calibration work
is necessary. Also, while I've included the source code to the user-interface portion of my player's software package, it will likely serve only as a starting point
for your own work, since I wrote it using a generally-unavailable compiler (Watcom C/C++ for DOS) and
a proprietary sound library (my own Miles Sound System). That being said, an experienced C/C++ programmer or Linux buff shouldn't have much
trouble with the software aspects of the project, since freeware and GPLed MP3 solutions are available on the net from
countless sources.
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Copyright © 2000 John Miles. All rights reserved.
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Copyright © 2000 John Miles. All rights reserved.
