Cf Audio Interface

[zeigerpuppy]

I am really keen to get this device running with my Z

http://www.core-sound.com/pdaudio-cf/1.php
[img]http://www.core-sound.com/images/PDAudio-CF-7a_100w.jpg\" border=\"0\" class=\"linked-image\" /]

It is a 24bit 96kHz stereo digital interface which I have used with an iPAQ in the past.  Awesome for field recording with a portable A/D converter and good Mic

There is an ALSA driver available at http://www.core-sound.com/pdaudio-cf/9.php
but the hardware developer says that he doesn't think it will work at full speed:

From: Len Moskowitz

Sorry, PDAudio-CF will not work on any of the Zaurus PDAs.  They don't have
the necessary CF card interface bandwidth.


Len Moskowitz
Core Sound
www.core-sound.com
Home of PDAudio

Is this true?  
Will it be possible to get this going in pdaXrom with ALSA support?

[zeigerpuppy]

On a more general note,
which Zaurus OSs have ALSA?

[Meanie]

On a more general note,
which Zaurus OSs have ALSA?
[div align=\"right\"][a href=\"index.php?act=findpost&pid=153598\"][{POST_SNAPBACK}][/a][/div]

pdaXrom and OpenZaurus

[zeigerpuppy]

This driver runs on familiar, do you think it would be difficult to port?
I guess it depends on the kernel it was compled for?
I'm a little out of my depth here, not sure which tools to use to build this and try it.

[speculatrix]

my guess is that you could get the card to work, but...

* might have to resample, e.g. only sample at half rate - 48kHz not 96 (perhaps combine samples) to reduce date rate by half
* might have to reduce sample from 24 bit to 16 bit at time of sampling to reduce data rate to 66%
* might have to busy loop rather than use I/O unless you can use DMA
* might have to sample and keep samples only in RAM, although I would guess the SD card bandwidth *might* be fast enough

--

back of the envelope calculations:
96kHz (rate) * 3 (bytes per sample) * 2 (channels) = 576 kB/s, which is within spec of the SD slot - people are able to play video off it after all... halving the sample rate and reducing the sample size would reduce to 192kB/s which should be easy if the Z does nothing else.

[speculatrix]

BTW, I have been wondering just how many organisations make I/O adaptors in compact flash format - so far I've only seen flash card to CF adaptors, serial ports, modems, gprs, ethernet and wireless adaptors.

I've also looked for CF type prototyping kits, so I could build a general purpose I/O module, which would be interesting, as it'd be nice to use the Z as an oscilloscope.

--- d'oh ---
typically, just after posting this, I stumbled across
http://www.compactflash.org/guide/comm.htm
and there are a few companies doing I/O modules.

[zeigerpuppy]

Thanks for the info,
I wasn't aware that the zaurus i/o was slower than the iPAQ H3950 (which I managed to get 24bit 48kHz stereo straight to CF with)
Is it the CF bandwidth that is the bottleneck or the Zaurus internal bus?
Processing power is also an issue (the reason only the more recent pdas will do 96kHz).
I guess I may have to wait for the PocketPenguin or get a second hand pda just for recording.

[Ling]

I imagine that by the time a PocketPenguin exists your photon computer with the inner ear implant will meet all your sound needs. Just thought I would share that the link in your sig is broken. I thought the error was nat instead of net in the hyperlink, but even making that correction brought up nothing. Good luck.