Hello all,
As a hobbyist project I am planning on constructing a digital audio mixer using a M68000 processor, along with some 16 bit serial A/D (MAX195) and D/A (MAX542) converters from Maxim. I will probably use a M68681 as a UART; also, I would like to use an analog fader (pot) fed into an 8 bit parallel ADC as the level control for each input channel. Adding a mute toggle to each input would take practically no extra work so I'm planning on doing this as well.
For the initial phase I am setting my goals as follows: - 16 bit resolution (external) - 48 kHz sampling rate (per channel) - 2 input channels (mono) - 1 output channel (mono)
The idea is to take two mono, line-level, analog input signals, sample them at 48 kHz or so (at 16 bits), "process" them, send a 16 bit digital output and convert it to a mono, line-level, analog output. Right now my "processing" will simply be something like: out = ( a*in1 + b*in2 ) / 2 where a & b are coefficients obtained from the position of the faders. I have no experience with DSP yet (junior level computer engineering student), but a good amount of experience with microcontroller systems and an excellent book on the 68000 (Microprocessor Systems Design, by Alan Clements), as well as a whole bunch of 68k family processors and support chips.
This is not supposed to be a commercially viable project (obiviously, I hope), but it would be nice to have a piece of homebrew digital equipment I could use as a DJ (I'd add phono amp's to use it with turntables). Thank you for reading this far, I know I ramble, but I would appreciate any advice on the feasibility of this project, ways to make it easier or better (without radical changes to the architecture), and especially the limits I will eventually encounter if I attempt to add more channels (stereo?) or "DSP" features such as equalization (this is probably not feasible on a 68000, but I can't easily tell).
-Thanks in advance for all helpful replies! =^) Alexander Miller
(this was cross-posted to comp.arch.hobbyist but it appears that new posts aren't appearing there, at least through groups.google.com)