[plug] A Call for help regarding embedding linux

Peter Revill arevill at bigpond.net.au
Thu Oct 24 18:44:44 WST 2002


  Ok boys and girls, im getting my first car as you may know, ill 
probably have it by next weekend, and boy do i have some plans for it.

The very first thing i want for it, is an mp3 player, now this is 
incredibly expensive, so i had a better idea: screw buying one, im going 
to make one.

Bare with me at this point and check out my proposal:

Goals:
a very cheap mp3 player that uses the cars stereo etc. to play mp3s and 
the cars power to run the computer, a computer in the boot provides the 
hard drive etc. required to run the mp3s, (except in Matt's car, which 
is a 4wd and is constantly bumped around and therefore must use a CDROM 
and floppy disk to boot Linux)

This is the basis of it, this is the first part , which means, what i 
basically need from people, whoever can help, is the following:

Any, any cheap computers you have lying around and your in perth, cpus, 
whatever, any cheap computer peices that you don't mind giving to a good 
cause, if you just want to help a fellow linuxl dood out now is the time 
:p. It will be open sourced ofcourse

I will be writing some java to do all this. me and my friend matt 
actually plan to start doing it for whoever asks for it if this goes well.

The final Document describing everything actually reads like this, for 
those intrested:


The mp3 car player By Nystrom and Nervlord

Roles:
Nervlord – Lead Programmer
Nystrom – Lead Engineer.

Goals:
a very cheap mp3 player that uses the cars stereo etc. to play mp3s and 
the cars power to run the computer, a computer in the boot provides the 
hard drive etc. required to run the mp3s, (except in Matt's car, which 
is a 4wd and is constantly bumped around and therefore must use a CDROM 
and floppy disk to boot Linux)

Recommendations thus far:
It has already been decided it must run Linux, and use mp123 to play the 
mp3s, the computer can be any 4 dollar computer with a sound card that 
functions, a Vibra 128 is the proffered model (25 dollars) as it 
provides excellent sound quality (PCI device however, which may cause 
complications.) A PCI computer would be the proffered computer, since 
this makes it easier for Linux to detect hardware. The Vibra is also 
well supported in terms of drivers for it.

Programming required: a Perl or Java script must be written that can 
parse an entire directory of mp3s, place them into a listed array, and 
accept input to begin playing a song, eg. Input 122 would play song 
number 122.

Ok, there are two ways: using the Java media framework, or using Java 
and the Java runtime class, if not, use Perl

Second thing: The CPU must be able to stand very hot temperatures, as it 
will be in the boot of my car, not exactly a cold place

that takes care of the major “definite” requirements

Recommendations not yet confirmed.

It is recommended the computer of course have no monitor
It is recommended the power be controlled with a inverter, however this 
can be quite costly, the inverter would have to be a 300 watt which is 
approx 185 dollars (marlows sells it at this price)

Types of input:

Obviously simply having it play songs is not the idle situation, it is 
therefore recommended the following methods of input:
1.a Mouse
Works by:
Simply click left and right to skip to certain songs

Advantages:
Easy to program for
Simple, and can easily reach anywhere, so i could push it through a hole 
in the car and simply click left/right for the songs i want.

Disadvantages:
Lack of flexibility, since it takes ages to skip to songs you enjoy.

2.A keyboard
use a keyboard hooked up by any method (serial to ps/2, it does not 
matter) and simply use up down arrows and other bits and bobs to select 
which song you want

Advantages
Flexibility, can be programmed to do just about anything we wish

Disadvantages
Big and bulky = looks bad, where to place?

3.A keyPAD

use a keyPAd, which is a keyboard but simply with only the right hand 
side (the numbers)

Advantages:
Simple, and a reasonably flexible input, while still not looking bad.

Disadvantages:
Difficult to find and probably expensive, may be difficult to find 
drivers under Linux for a simple keypad

Another method proposed is to simply load the data for what songs to 
play from a floppy disk, meaning every time i enter the car, it simply 
checks the “playlist” on my disk, write a program that runs on my main 
computer which takes care of writing new playlist data,

These are all our methods, version 1.0 must meet all requirements, 
version 2.0 will possibly have an LCD depending on time and inclination.




Comments? suggestions? Willingness to help?



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