[sdiy] gate sequencer

[Andreas Gaunitz]

If you don't want to prgram a PIC or other microprocessor... use a 555 
timer. The 555 cycle time is defined by a combination of one resistor 
and one capacitor.

You have 16 steps, and one circuit for each step. Each circuit has a 
timing pot. You have a counter 1 to 16, that is triggered by the 555 - 
it increases whith each cycle of the 555. The counter decides which 
circuit is in use, using a 16-line decoder, for example 74154.

The pot defines the cycle length of the 555. Short cycle means minus 
delay on next note, long cycle means plus delay.

There's of course another pot that defines the duty cycle of the 555, 
which is the gate length.

Not sure if it makes sense, am a little drunk ATM.

HTH
-Andreas


-------------------------------------------------------------------
2004 nov 18  kl. 19.33 skrev Rafael_Cohen at prusec.com:

>
> Hi,
> This is my first post here, and usually I lurk on a list for a while 
> before
> posting, but I am anxious to get some feedback about an idea I have.  
> Let
> me first say my tech skills are limited.  I have built my own contact
> microphones and a little Velleman "sound-to-light" kit with no 
> problems.  I
> have basic tools (no scope) and I'm learning to read schematics (from 
> Craig
> Anderton's book I got from PAIA)... OK, I'm a newbie.
>
> I want to build a gate sequencer.  I'm curious how difficult it would 
> be
> and where I would start.  I was thinking 2 rows of 16 toggle switches 
> with
> LEDs to indicate on/off status.  In it's simplest form, that's pretty 
> much
> it.  With a clock input and two ouputs for the gate signals.  I don't 
> need
> to program note/cv values, just gates on/off in time.  The only other
> feature I'm itching for is a micro-timing knob for each step to push 
> the
> signals a little bit early or late.  I have this sinking feeling that 
> might
> make the project about four times as complicated.  Right now, I'm not 
> even
> trying to worry about pattern length, pattern direction, any of that.  
> I
> really have no idea how to go about it.  I hope you don't get posts 
> like
> this all the time... "I have a frying pan and a coat hanger, please 
> tell me
> in monosyllables how to build a particle accelerator..."
>
> Anyhow, I have the desire and energy to build and learn.  Any help, 
> advice,
> idas are appreciated.
>
> Rafael
> Brooklyn, NY
>
>