Author Topic: Portable Wave format recorder using USB (RAM) dongle ... possible ?  (Read 4023 times)

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

« Last Edit: June 02, 2006, 10:21:05 PM by Eb7+9 »

cd

Re: Portable Wave format recorder using USB (RAM) dongle ... possible ?
« Reply #1 on: June 02, 2006, 11:24:26 PM »
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

Re: Portable Wave format recorder using USB (RAM) dongle ... possible ?
« Reply #2 on: June 03, 2006, 01:07:44 AM »
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.
Eschew paradigm obfuscation

A.S.P.

Re: Portable Wave format recorder using USB (RAM) dongle ... possible ?
« Reply #3 on: June 11, 2006, 04:50:36 AM »
maybe these: http://www.oxsemi.com/ have some sort of solution?
Analogue Signal Processing

RaceDriver205

Re: Portable Wave format recorder using USB (RAM) dongle ... possible ?
« Reply #4 on: June 11, 2006, 05:52:32 AM »
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.  :icon_biggrin:
EDIT: You will have to know how to program fairly well, mind. Hope you have a crack at it.
« Last Edit: June 11, 2006, 05:55:26 AM by RaceDriver205 »

Peter Snowberg

Re: Portable Wave format recorder using USB (RAM) dongle ... possible ?
« Reply #5 on: June 12, 2006, 08:54:55 PM »
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!      
Eschew paradigm obfuscation

A.S.P.

Re: Portable Wave format recorder using USB (RAM) dongle ... possible ?
« Reply #6 on: June 13, 2006, 02:10:19 AM »
ahh...just a case of reading the smallprints in your weekly "Elektor"-newsletter, baby.
(this one from june, 9th.)  :icon_wink:
 :icon_biggrin:

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