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connecting 8052 to adc and dac

Started by CAFxX December 22, 2003
Mike Turco wrote:

> > "Ian Bell" <ian@ruffrecordsDOTworldonline.co.uk> wrote in message > news:3fe7f72a_3@mk-nntp-1.news.uk.worldonline.com... >> Mike Turco wrote: >> >> > >> > "Frank Bemelman" <fbemelx@euronet.invalid.nl> wrote in message >> > news:3fe79bef$0$195$1b62eedf@news.wanadoo.nl... >> >> "Jim Stewart" <jstewart@jkmicro.com> schreef in bericht >> >> news:g6adnccAfOyJDXqiRVn-sQ@omsoft.com... >> >> > Frank Bemelman wrote: >> >> > >> >> > > Audio CD's are 16 bits at 44.1KHz, but 24 bit @ 96KHz doesn't >> >> > > sound unreasonable to me, for professional gear used in studios. >> >> > >> >> > Except that 24 bits is a s/n ratio of 144db. >> >> > I wouldn't be able to make a piece of wire >> >> > have a s/n ratio of 144db (: >> >> >> >> Me neither ;) >> > >> > Perhaps this is a product for people with very discerning ears ,~) >> > >> > The poster did ask for suggestions. >> > >> > Microchip makes a line of ADC's, and a simple DAC is just a bunch of >> > resistors. If the OP would be more specific about what it is he is > trying >> > to accomplish, that would lead to better suggestions. >> > >> >> I thought he was quite specific. He wants a single channel of audio in, >> apply effects to it in the digital domain and send the result to a DAC to >> recreate analogue audio. The 24bit/96KHz bit only came about because I > took >> the trouble to look up the chip he said he was looking at using. > > I meant specific in terms of quality. I used to work in the toy industry > and "quality" often meant "barely intelligible".
Me too and it still is. Ian
On Mon, 22 Dec 2003 18:37:01 +0100, CAFxX wrote:

> hi, > i was wondering how to connect an adc and a dac to a 8025 (DS89C420). do i > have to use the two UARTs or it's better to use the "raw" i/o pins? what i'm > trying to do is a sort of audio filter: the signal is converted in digital, > read by the 8052 (where the fx are applied), and sent to the dac. > moreover i'm using BB's PCM1802 as the ADC and PCM1744 as the DAC. the > problem is these are all stereo adcs and dacs. do anyone knows about > audio-oriented mono adcs and dacs? > thank you for your help, CAFxX.
Use an Analog Devices ADuC816 instead, it has both the ADC and DAC onboard. Or some other processor that contains both and avoid having to interface separate components.
> > I meant specific in terms of quality. I used to work in the toy industry > > and "quality" often meant "barely intelligible". > > Me too and it still is.
That's why they print the word bubbles on the packaging. Many toys, I can't understand what the hell they are saying. If I see the word bubbles, that gives my audio processing firmware a list of possibles and with those in memory, I can always guess what phrase is actually being spoken.
first of all thank you for your replies.
as ian pointed out i just wanted to build a sort of multi-effect processor
for mono audio signals.
the adc and dac actually do have a 24/96 resolution (even 24/192 fot the
adc) but they also support 24/48 and 24/44.1 so i wouldn't mind that. the
problem simply was how to connect them (they all are serial, but they do
have the data pin, the data clock pin and the l/r clock pin (since they all
are stereo)).
i took a look at analog device's microconverters but their DACs only works
at 12bits. otherwise they would have been perfect. maybe there are other
solutions around but i didn't find them. if someone knows them...

thank you very much, CAFxX.

"Ian Bell" <ian@ruffrecordsDOTworldonline.co.uk> ha scritto nel messaggio
news:3fe7f72a_3@mk-nntp-1.news.uk.worldonline.com...
> Mike Turco wrote: > > > > > "Frank Bemelman" <fbemelx@euronet.invalid.nl> wrote in message > > news:3fe79bef$0$195$1b62eedf@news.wanadoo.nl... > >> "Jim Stewart" <jstewart@jkmicro.com> schreef in bericht > >> news:g6adnccAfOyJDXqiRVn-sQ@omsoft.com... > >> > Frank Bemelman wrote: > >> > > >> > > Audio CD's are 16 bits at 44.1KHz, but 24 bit @ 96KHz doesn't > >> > > sound unreasonable to me, for professional gear used in studios. > >> > > >> > Except that 24 bits is a s/n ratio of 144db. > >> > I wouldn't be able to make a piece of wire > >> > have a s/n ratio of 144db (: > >> > >> Me neither ;) > > > > Perhaps this is a product for people with very discerning ears ,~) > > > > The poster did ask for suggestions. > > > > Microchip makes a line of ADC's, and a simple DAC is just a bunch of > > resistors. If the OP would be more specific about what it is he is
trying
> > to accomplish, that would lead to better suggestions. > > > > I thought he was quite specific. He wants a single channel of audio in, > apply effects to it in the digital domain and send the result to a DAC to > recreate analogue audio. The 24bit/96KHz bit only came about because I
took
> the trouble to look up the chip he said he was looking at using. > > Ian >
"CAFxX" <cafxx@n-side.it> wrote in message news:<bu4fj3$6dj$1@lacerta.tiscalinet.it>...
> first of all thank you for your replies. > as ian pointed out i just wanted to build a sort of multi-effect processor > for mono audio signals. > the adc and dac actually do have a 24/96 resolution (even 24/192 fot the > adc) but they also support 24/48 and 24/44.1 so i wouldn't mind that. the > problem simply was how to connect them (they all are serial, but they do > have the data pin, the data clock pin and the l/r clock pin (since they all > are stereo)).
Yep, they're all stereo. (Or they have multiple pairs!) Why don't use choose a DSP that has built-in I2S ports? In that case, you might actually be able to do something interesting. Another option is to use a simple CPLD that takes I2S in and gives you parallel out, and parallel in to I2S out. If you're clever, you can figure out how to extract only one of the channels, and if you're even more clever, you'll realize that you can grab the 24-bit data in 8-bit chunks, so you don't need 48 bits of shift register. If you do it this way, you're also not wasting your micro's time bit-banging a couple of I/O ports. I still think a DSP is the right way to go. --a