[sdiy] CC-Modular

[Seb Francis]

Daniel Araya wrote:

> What about incorporating a small uC in every module and have a
> central module just collect the data and save the patches via some
> sort of serial bus? Every module has its own id number so you can
> connect modules to the bus as you make them. A patchcord system can
> be accomplished by pressing an "output" button on a module and then
> an "input" button on another. Every module has a digita bus
> and say eight analog buses to route the audio and control voltages.

I don't think you even need a uC in each module .. just one mux for each intput or output.  If you want to have plenty of analog busses (IMO 8 is too few), it doesn't really save on the number of switches needed, but it allows them to be added in a modular way with each new analog module.

e.g. In 16 analog-bus system, every input and output in each analog module has a 16-1 latching analog mux, and a couple of logic chips per module to "select" the module.  For 7 bit module addressing (128 modules should be enough!), a dual 4-input NAND and hex inverter would be enough for half the modules, with the other half needing an extra inverter.

Would need a 12-wide digital bus though (including "enable" signal).  Better might be to have a central digital decoder with a single digital "enable" line (+4 bit mux address) going to each module.  This means each module needs exactly N 16-1 analog mux chips where N is the combined total of inputs and outputs.  Still lots wires in the analog bus tho (and the same number even to modules which have only very few IOs).

This would be really scaleable (as long as you start with a big enough analog bus width and max number of modules - determined by the central digital decoder).  Not sure if cross-talk would be more of an issue with a bus system tho?

Seb