Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!cs.utexas.edu!swrinde!ucsd!anise.acc.com!ivucsb!todd From: todd@ivucsb.sba.ca.us (Todd Day) Newsgroups: comp.dsp Subject: Re: Digital Mixer Using Burr-Brown 200 Khz ADC Message-ID: <1989Sep28.164854.6682@ivucsb.sba.ca.us> Date: 28 Sep 89 16:48:54 GMT References: <9231@pyr.gatech.EDU> Organization: Disillusioned Graduate Hackers, Santa Barbara, CA Lines: 47 byron@pyr.gatech.EDU (Byron A Jeff) writes: ~----------- --------- --------- -------- -------- -------- -------- ~|8 |--|Analog |--|Filters|--| |---| | | | | | ~|Audio |--|Multi- | | and | | ADC | | DSP |--| DAC |--|Filter| ~|channels |--|plexors|--| S/H |--| |---| | | | | | ~----------- --------- --------- -------- -------- -------- -------- ^^ ^^^ Eight lines here. There should be two lines since it is a dual ADC. Sounds like it might be feasible. Does it have serial or parallel output? Serial 44.1 kHz * 4 channels * 16 bits/channel = 2.822 MHz I think the 56000 can handle this. Only half of what you need, though. You might be able to do it with the TM$32030, as it has two serial inputs. Parallel Either 56000 or 32020 can handle this, if you can figure out a way to merge the data streams. ~If samples can be obtained for ~$50 then a box for between $200 to $300 ~could be realized. If the DSP is fast enough then another ADC could ~easily be added for a grand total of 16 channels. Your biggest problem is that the samples are not arriving at the same time. Actually, I guess you could use an interrupt routine to store all the samples, then have the DSP act on them when all have arrived. Remember that since you are using an analog MUX, the samples can't all be done at EXACTLY the same time, so there will be a slight delay between all of the channels. Also, if it is serial, you'll have to use TWO 56000s and have them talk to each other (not really that hard). Could do some killer filtering, though. There might be some chips from AT&T that are cheap and have two synchronous serial inputs. The TI chip I mentioned is expensive. -- Todd Day | todd@ivucsb.sba.ca.us | ivucsb!todd@anise.acc.com "Ya know, some day these scientists are going to invent something that can outsmart a rabbit" -- Bugs Bunny