Portable Wave format recorder using USB (RAM) dongle ... possible ?

[Eb7+9]

I'm curious about what might be involved in processing the output of an A/D converter and have it written in wave format inside a USB RAM dongle for later transfer to a PC ?? 

what I'm thinking is this : a battery operated unit (9 or 18v) with a clean/lowNoise analogue pre (up to +55dbv, no phantom) (ii) 24bit A/D converter, @44.1k (iii) a logic block writing the stream into wave format through a USB channel ... start/stop buttons (automatic shutoff when full), and a reset/erase button ...

is there lots of programing involved here or does a simple hardware solution already exist ??

TIA, JC

[cd]

Yup, lots of programming involved - not to mention SMD chips

A bunch of simple hardware solutions exist - look for info on the Edirol R1 or Core Sound PDAudio, to name two.  Of course, they're not cheap.

Better question, does a CHEAP, simple hardware solution already exist?  There are chipsets designed for MP3 players that can do recording, then again I don't know where you'd get them in 1s and 2s (or less than 1000s).  Anyone?

[Peter Snowberg]

There isn't much from a technical end required other than a USB host port and that's where things get more complex. All USB data transfer is initiated by a host interface and all the simple USB enabled microcontrollers have USB end-point interfaces so you can't hook them up to other end-points and have anything. This was one limitation the creators of FireWire did away with because it was such a big restriction.

One you have a chip with a host port you just need some buffer RAM and enough firmware to tackle the enumeration of the available USB resources and the data transfer to them. Not a small task by any means, but also not beyond the complexity of many other embedded systems.

In the end I think it would be much easier to use an existing USB mass storage controller chip and a multiplexer to connect the FLASH to either the USB controller, or to your A/D subsystem. That configuration isn't that difficult to develop.

[A.S.P.]

maybe these: http://www.oxsemi.com/ have some sort of solution?

[RaceDriver205]

You might want to check out this:
http://www.jaycar.com.au/productView.asp?ID=ZZ8570&CATID=&keywords=usb+pic&SPECIAL=&form=KEYWORD&ProdCodeOnly=&Keyword1=&Keyword2=&pageNumber=&priceMin=&priceMax=&SUBCATID=

Jaycar is where I buy all my stuff, and im suprised they added such a high-end IC to their stock list. They tend to keep their parts inventory pretty fundamental. Those ADCs and the USB interface sounds right down your alley. 
EDIT: You will have to know how to program fairly well, mind. Hope you have a crack at it.

[Peter Snowberg]

maybe these: http://www.oxsemi.com/ have some sort of solution?

Ahhhh, an analog fellow with such supergroovalistic digital prosifunkstication.   Thank you!

They have the chips to pull this one off. Very cool!      

[A.S.P.]

ahh...just a case of reading the smallprints in your weekly "Elektor"-newsletter, baby.
(this one from june, 9th.) 


http://www.elektor-electronics.co.uk/Default.aspx?tabid=1
(contents differ a bit from country to country...)