work-around for sequencer delayed rst input?

motorik · Joined: Feb 06, 2009 Posts: 3 Location: Northern California

I'm working on some keyboard-triggered sequencer stuff, and am trying to get the first step of the sequence when I hit a note. Unfortunately, the delayed reset thing really wants me to get the second step of the sequence. The best work-around I've gotten is to run the gate signal into the 'park' input, and then through a logic delay into the 'rst' input. While this works, I suspect there's a better way of doing it, and have tried all sorts of things with flipflops and s&h but seem to be missing something obvious. I'm sure this is a common issue ... suggestions?

iPassenger · Posted: Sat Feb 07, 2009 5:25 pm Post subject:

This is a rather clumsy solution:

It only works while you press a key but seems to reset properly.

EDIT: I added another version which uses a logic invertor and another AND gate to allow you to only trigger the note once (rather than hold a key).

Note Sync Reset.pch2

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Note Sync Rese2.pch2

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motorik · Joined: Feb 06, 2009 Posts: 3 Location: Northern California

For whatever reason I can't attach documents with OSX Firefox ... the best solutions I've found so far are here;

http://www.solipsist.org/seq_rst

I'm only triggering notes from the kbd in these.

The first triggers a logic pulse from an incoming gate which goes to the park input, and also through a short delay into the rst input. The second, and better method, also sends a short logic pulse to 'park,' but the delayed reset is done by a second logic pulse clocked by the negative edge of the first pulse.

The best solution would be something that takes the positive edge of the incoming gate and sends it to two logic pulse objects in sequence, on subsequent control rate system sample intervals, which go to the sequencer's park and reset inputs respectively. I suspect the sequencer 'park' input might not be designed to handle this sort of thing.

Ideally, there would be a non-delayed sync input, but oh well.

Antimon · Posted: Mon Feb 09, 2009 11:06 am Post subject:

Is this what you're after? I tweaked your delay example so that the keyboard gate triggers a pulse that goes into both the rst and the clk input.

/Stefan

clock_and_rst.pch2

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clock_and_rst.pch2

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motorik · Joined: Feb 06, 2009 Posts: 3 Location: Northern California

After running some tests against other synchronized material, I think clocking the reset on the negative edge of a short logic pulse to the 'park' input works the best. I'm sure there are more theoretically perfect solutions used by uber logic guys, but it seems to work well from a practical standpoint. Thanks much for the responses, and taking time to post patches ... seeing other people's solutions is a huge help.