[geeks] home mp3 system suggestions

Joshua D Boyd jdboyd at cs.millersville.edu
Thu May 30 19:45:12 CDT 2002


On Thu, May 30, 2002 at 08:03:54PM -0400, Nathaniel Grady wrote:
> Few ideas: 
> 
> 1) TI/ Burr Brown make a "usb streaming audio codec" chip that has a usb
> in on one end and analog out on the other. I snagged some samples from
> them for my own use but still haven't gotten around to using them yet
> (fine pitched SMT, not sure if i can actually solder wires to them).

I've heard of those.  They are supposed to be really good, and
reportedly they had a hard time getting them to work right (there is a
case study somewhere on the net).

DaveM used to be able to deal with SMT stuff, but I think he sold that gear.
 
> 2) A lot of uC's have UARTS for RS232 / RS422 / RS485 / CAN (the latter
> two of which are multidrop iirc) as well as i2c (for the dac). Maybe
> something like  20mhz AVR or something should be able to handle the data
> rate w/o much trouble and have cycles left over to drive a LCD showing
> song name and a few buttons... The problem of course is that PC's don't
> often have anything but RS422 / USB. Maybe you could find a multiport
> serial card off ebay that could do 1 or 2 Mb/s and run point-to-point
> RS/232 (only really need 4 wires, maybe 5 if you wanted power also). 
> 
> 3) SBC - for $200 you could get something like a 386 sbc (such as
> www.sumbox.com - don't know anything about them - just saw an add in
> circuit cellar) that has Ethernet and runs linux? Zworld
> (www.zworld.com) has one for $249. 

Yep, definately too expensive for putting in every room.  See, the
rather nice Cirrus Logic CS4334 chip is $5.  LCD display would be like
$20 per unit.  Bottons a few pennies.

Then on the server side, I just need to build a custom ISA or USB controller
to setup a serial connection out to each unit (perhaps differential,
most likely running over CAT5).  Ideally the controller would have a
decent buffer, but that might be beyond my skill level, unless I can
find one made for DACs.  

So, maybe $30-$40 per room, $150 server side.  At least that is the
sort of price range I'm aiming for if I'm to actually do this.
 
> 4) Microcontroller board with ethernet like a Netburner
> (www.netburner.com) - $99, has 10/100mbps ethernet. Iirc, Rabit also has
> something similar that's cheaper (www.rabbitsemiconductor.com) 

I think that would be too hard.
 
> 4) Radiometrix has wireless modules that can do up to 160kbps serial
> communications. Don't know pricing but I remember being pleasantly

Too slow for uncompressed audio, likely to be too expensive.


-- 
Joshua D. Boyd



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