I am currently going ti make an Mp3 Player for my car. It is going to be an in dash unit. It will be built around a small 3.5" form factor embedded system (http://www.orbitmicro.com/products/e...er/EBC-350.htm <--This One</a>)

The only problem I have is running the sound straight from the computer's Speaker Out to the car speakers. I know I need an amp between there (or least I have been told). What kind of amp would I need, and is it possible to get one small enough to fit in a 178x50x135 (mm) DIN size box?

This is the only thing I am stuck on... so ideas are highly welcomed. Thank you.

 

Interesting.

You say the MP3 player will be 'built around' this,
well it looks like a small motherboard, probably for
a laptop.

You say that your only problem will be an amplifier
to drive the speakers in the car.

So what will you use as media to hold the MP3's ?
Probably CD's, so you will also need a CD player.

Maybe a hard drive, you can get them quite small with
large capacity. How well they will stand up to the
vibrations in a car i don't know.

And the program to de-code the MP3 compression.
If you are using a HD then i suppose that program
could be on there too.

If you're using CD's then i suppose the de-compress
program could be on each CD.

Or maybe you could put the de-compress program into
ROM, but its quite a lot.

How do you propose to pick a tune from your MP3's ?

Maybe one of those odd little panels that VHS players
use could be adapted, and its buttons re-wired.

Maybe a very simple double seven segment display, and
a few press buttons could do it.

I would be interested to hear more about this.

Regards, John

 

Since you are stuck only on building a power amplifier, I suppose that your MP3 thingy is working, am I right?

Anyways, I would suggest that you use one of the TDA series ICs for car radio applications (eg: TDA1554, 7265, 7350, 7375, etc.).
Go here --> http://www.st.com/stonline/products/selector/203.htm
and choose an amp that best suits your needs (a.k.a. power output )
Happy building.

 

Sorry, all wanted to know was how to get the audio from the motherboard to the my car speakers, so I didn't tell of the other features. But here are the other specs...
I have a laptop HDD running Win98 Lite, which has Winamp installed to play all formats of music (Mp3, CDs, WMP ...)
Songs can be laoded via both a USB pocket drive or the slime CD-ROM (This one)
I have a 20 x 2 LCD to display the track/ Mp3 info. ( Here ). Which I have a winamp plugin for.
To contorl all this I have a 5 button serial interface setup. (Off a Winamp plugin) Plus I also have a remote control that runs Winamp commands ( Here).
To power all of this, I have a DC-DC converter that is 10-13V Input 5V output.
So the only thing that obstable now needed to be breached is how to get the audio to the car speakers.

 

Does your car-stereo have a cd-changer input? if so, there are 'fake-changers' available for many car stereo's; they make your radio believe there is a changer attached, so your radio will switch to the changer input... just connect the line-out of the motherboard to the cd changer line-in and music will play as normal...

Another option would be to buy a radio with a aux in...

just a question, do you have a lcd screen to display the pc's vga ?
if so, can you tell me the make. Been looking for a small lcd that takes vga for a long time

 

I know not of any that are specifically vga. The LCD I am using is serial interfaced. I know of some for PAL/NTSC input, TFT, and even digital CMOS, but none other than that.
Mini LCD display

 

The mobo has regular AC97 audio and a stereo audio socket. I'd be tempted to make life easy, and just go and buy a regular car audio amp. You can run the speaker out to the amp no problem at all... you just need a stereo mini-phono to RCA cable.

Edit: If you want to DIY, there's a few circuits and kits floating around online. Depends one your needs and how much sound you want to make.

 

I agree with Ricardo.
Compared to the other problems with MP3
an audio amplifier is a very minor difficulty.

I would like to see pics of the finished item.

Best of luck with it, John

 

Surfsire,

You can find a lot of information about mp3 car audio here:

www.mp3car.com

It seems it would be easier to just get a regular car amp like Ricardo suggested.

Exo,

Yes they make a small LCD that takes vga now. I believe it runs around 400-500$. Don't really remember the price. Xenarc makes it.

http://www.xenarc.com/product/700y.html

I am not sure if anyone else has come out with one but google it

-Dennis

 

Thx for that link
If i can get my hands on one of those i can finally start building a pc into my car