hi derek,

Am Mittwoch, 11. Oktober 2006 19:35 schrieb derek holzer:

I wanted to bring this super interesting discussion back, since it only touched on a few different things before wandering off into ModTracker territory (not so interesting for me...)

If I wanted to program an Arduino to send out Control Voltage for a modular synth, what would the resolution be? Would it be better than MIDI? Enough for microtones? Could it make quick modulations? (I saw that the filtered PWM method which some mentioned here is not good for fast changes in voltage.) How many channels could I get out of one board? I have two, but I haven't touched them yet. Would I need extra hardware (filters etc) to modify the voltage before it goes to the synth? Would anyone be interested in helping with such a project? In the Berlin area even? Are there any programs written for the Arduino that do this already?

a really fast way is to use an external dac chip. for example something like http://focus.ti.com/docs/prod/folders/print/dac7614.html

there are lots of different one, just choose the number of channels and resolution, and take care that it comes in a package that you can solder. pdip are the big standard packages, soic is smd, but still easy to work with: http://focus.ti.com/paramsearch/docs/parametricsearch.tsp?startIdx=1&end...

hint: you can get samples from ti. click the "samples" link at the top of each product page and choose the one you want from the list. you need to register first.

with such an dac you get real voltage output that doesnt need to be filtered for your application. altough most dac's are serial, the communication is very fast and often allows up to audio sample rates or more. implementing the code to write the dac is fairly simple, since it usually is a standard i2c or spi interface. its also well explained in the datasheets.

best, d.

greets,

chris