[sdiy] analogDNA

[John Loffink]

CANbus will be your most robust solution.  It is expensive though, and not
as widely supported as I2C.  Your processor of choice is an $8-9 part.

Your other option, as noted, is I2C.  I2C has a lot of problems.  However,
it is very common, with many $1-3 microcontrollers supporting SPI and I2C
simultaneoulsy.

I2C Multimaster is not well supported, so you are better off making your
patch module the I2C master and all others the slaves.

Long stubs also don't work well, and you might have these in a modular
environment.  You will probably need I2C repeaters/hubs/extenders to daisy
chain and route star configurations to modules within a cabinet.

You can run I2C at any speed, not just 100/400 Khz, so cutting down the
speed helps with reflections on long busses.

Misbehaving I2C devices have been known to lock up the bus, so some
implementations run a reset signal from the master to all slaves.

John Loffink
The Microtonal Synthesis Web Site
http://www.microtonal-synthesis.com
The Wavemakers Synthesizer Web Site
http://www.wavemakers-synth.com


> -----Original Message-----
> From: owner-synth-diy at dropmix.xs4all.nl [mailto:owner-synth-
> diy at dropmix.xs4all.nl] On Behalf Of Rob
> Sent: Saturday, June 17, 2006 6:45 PM
> To: synth-diy at dropmix.xs4all.nl
> Subject: RE: [sdiy] analogDNA
> 
> Hi,
> Useful feedback and ideas from the list...as usual!
> 
> I2C is a serious contender, but I'm using SPI on the module PCB's - so
> maybe
> I could mix them? CAN is certainly more complex but its becoming popular.
> 
> The analogDNA design doesn't transport analog signals, as shipping 24-bit
> data realtime for 100 modules is a bit tricky and possibly expensive to
> develop as Synth DIY.
> 
> It's not the ultimate dream machine...but a Matrix module provides analog
> circuit interconnection and patch storage - a modern AKS Patch Panel. It's
> clunky because you need to wire each jack to the Matrix module, but we
> won't
> want to make the whole synth an armchair...!
> 
> I'll put some design and progress notes at www.emulatorarchive.com
> 
> Regards Rob
>