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Re: Audio on the LX

On Sun, 12 May 2002, Jarkko Tuomi wrote:
> -Get a devboard with ATA and avoid soldering a lot of wires.
> -Go for an external MPEG decoder chip. The cpu might just have enough time
> for the job, but only if your routines use integers. MPG123 with floating
> point emulation is not going to work for sure. In addition you would also
> need to write a kernel driver with double buffering for the DAC.

I doubt the E100LX has enough power to do mp3 decoding in software, even if 
the multiply figure is high enough, the lack of a MAC-instruction hurts.

A standalone small mp3 decoding chip is like 5-10 USD, and very easy to 
connect to the LX using either the gpio or the synchronous serial ports.

I built a board with the LX and the STA013 MP3 decoder and associated analog 
parts, it was really easy and the sound quality and noise levels were great.
Even without designing a full custom PCB, it would be possible to hook 
this up to the devboard.

> -Stick to a simple LCD with a built in controller. A real graphics chip
> would almost certaily result in a custom made circuit board.

Right.. I've used a simple graphical LCD, inboard controller, and it was 
easily connected to the Etrax parallel ports.

> IDE interface is hardly going to be a problem, it uses DMA and is
> surprisingly fast. The power consumption is around 1-2 W without a harddisk.

No problem there, as long as you get a board with an ATA connector or can 
make one.