[sdiy] MIDI to Arpeggio clock

[Jason Proctor]

yeah i'm starting to think of nice visual applications of arduinos 
etc, for sure. the evilmadscientist website has a fab LED-driven 
sundial type clock. drive that off MIDI instead of the realworld 
clock, heehee.

arpeggiator clock inputs - the ones that use 1/4" jacks - are usually 
designed to interface to pre-MIDI stuff and are based on 16th notes 
rather than 24ppqn as such. so the conversion process listens for the 
MIDI start command, then sends 1 clock pulse for every 6 MIDI clock 
messages.

there's lots of ways of clocking gear which is just looking for a 
voltage spike. if you have a MIDI to CV converter then you can use 
any of the voltage outputs as clocks. program an aftertouch or CC 
spike every 16th note, use that. etc. one thing to watch out for 
though with uproc based clock sources is that they typically work off 
5v, and some synths notably old ARPs etc require more than that. 
hence some 10v comparators are required etc.

the Arduino approach will cost a little more than the preburned PIC 
one, but the massive advantage is that you get a multipurpose I/O 
module out of it. assuming you can hack a little software. and there 
are always people around who can help out with that :-)



>Jason,
>
>I was thinking of using this arrangement or one similar to create a 
>MIDI driven lighting unit as well... It would be cool to add an 
>ADSR-type of filter for light effects...
>
>I was initially going to cannibalize an old drum machine and use it 
>for MIDI Dig/Analog conversion and then use something else to 
>manipulate the signal.
>
>In my naivete - I was not aware that the arpeg clock in was based on 
>24 ps pulses, I had previously plugged in just an 'audio out' from 
>one of the drum channels which actually worked - in a weird sort of 
>way.
>
>I do like the plans that Tom suggested below - 
><http://www.angelfire.com/geek/srlabs/diner.html>http://www.angelfire.com/geek/srlabs/diner.html 
>- but the Arduino plan intrigues me and it seems like some 
>additional flexibility could be done from a programming standpoint.