[lug] Ethernet sound card

[Nate Duehr]

On Thu, 2002-09-05 at 20:38, Peter Hutnick wrote:

> This is specifically *not* what I am looking for.
> 
> 1. Only plays formats that it understands (this is the killer).

This is probably due to off-loading the processing of the compression to
a microprocessor custom-built for the purpose of decoding those
stream-types in the device.  Typically these are hard to find in
low-quantity for experimenters and licensing fees and NDA's go with
them.

> 2. Costs 4 or 5 TIMES what I think it would cost to make the "Ethernet
> sound card" (or to mass-produce them and sell 'em at a tidy profit).

Good luck.  You'll likely find that super-mass-production,
professionally created boards, and surface-mount devices stuffed by
automation will get the price down to a point where they're able to be
sold to the general public.  And that price will probably be close to
what the Turtle Beach device costs.  More info on that below...

> 3. Relies on some sort of server software.  More specifically, it is a
> client, what I am driving at is a /peripheral/.
> 
> They call it a "smart stereo component."  I am looking for a stupid stereo
> component.

I don't think you're going to find that anything other than an old PC is
cheaper.  (Plus it's the only way to keep this on-topic for a Linux
mailing list... GRIN...)

Assuming you already have Ethernet pulled to where the stereo is...

Old 150 MHz Pentium II class machine, about $150 MAX if you have to buy
it, many folks give them away.  Probably already with an Ethernet card
in it and hard disk.  You can perhaps also net-boot it off a bigger
linux box, depending on amount of brain-damage required... (GRIN).

To design the "appliance"... you'll need:

Custom PCB boards [*IF* you can keep the size of the board to 2" x 3"
you can get three boards for just under $100 delivered - you can not
order one at a time at that price]  {Total $33 minimum per device}

Microprocessor/Microcontroller (all depends on design) with Flash
capability to set IP address and "remember" it and to handle user
"interface" issues, if you have any.  You'll at least have to somehow
program a MAC address into the device unless you find a pre-built
Ethernet interface that has the manufacturer's Ethernet ID in it. 
Otherwise you'll be making up your own MAC addresses and could clash
with registered MAC address numbers] {Realistically $10 minimum per
device $20 with all "glue" devices for the micro.}

[For "popular" micros, see www.microchip.com and www.atmel.com as
examples - individual microcontrollers are typically priced in low
quantity at anywhere from $5-$20 and even then the prices don't drop
much until you hit a quantity of 1000]

Development environment for Micro (can be free, depending on how much
you like writing in Assembly)

Programmer for Micro - anywhere from $40 - $2000, depending on needs. 
$40 ones aren't going to cut it for mass-production to keep costs down. 
{$100 for a decent hobbiest one}

Ethernet interface chipset and connectors or pre-built Ethernet to XYZ
(pick your protocol, insert here) device.  {??? Guessing about $35 in
low quantity and those may not be fast enough}

RAM {??  How much do you need?}

Hardware interface chips to RAM  {???}

D to A converter circuits and chipset (if you're dumping raw digital to
it, you'll have to find something that can output your analog signal) 

Amplifier circuit and chipset or discreet components and
jacks/connectors to go to the stereo (this line-item doesn't even come
close to describing how to isolate the circuit properly and keep a
fumblefingers from blowing it up if they hook things up wrong) 
{Probably at least $50}

Power supply circuit devices and wall-wort or other power supply of
adequate voltage and current for your application {$7}

The list keeps growing...I'll stop here. {I stopped when the price hit
around $250}

I doubt you can get the price any cheaper on a "device" you custom-build
than either the "appliance" boxes or a used PC with a soundcard,
ethernet card, hard disk, and RAM.  All older PC devices are cheaper
because their initial costs were eaten up looooong ago by someone else. 
Re-treads.  :-)

Nate

> 
> -Peter
> 
> 
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-- 
Nate Duehr, nate at natetech.com