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Chysn / O_C-HemisphereSuite

Hemisphere Suite is alternate-alternate firmware for Ornament and Crime, featuring a dual-applet framework with dozens of different modular functions.
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Proposed Buchla pulses update #29

Closed mathomas closed 5 years ago

mathomas commented 5 years ago

Hey there. I have a 2OC that I was itching to put to work as a clock divider (etc) in my small Buchla setup. However, I found that pulses weren't sufficient to trigger (at least) the 281e.

What you find here seems to get pulses up to about 10v in my scope (and does successfully trigger the 281e). I've scoped most, if not all, the other pulse/gate oriented things and they look pretty good. I have not tested musically, but I have pretty high confidence at this point.

I'm not sure if you already have a much better way of approaching it, but if not, at least what I'm doing is a possibility?

mathomas commented 5 years ago

Note: I have another branch going regarding CVs but that's a bit trickier. I've successfully scaled them on the high-side to net 10v peak. But I haven't yet figured out how to properly offset to avoid negative/bipolar results from LFOs, etc.

Chysn commented 5 years ago

Thank you for your contribution. This looks good, and I'll probably integrate it shortly.

Please note that negative values should be prevented in OC_DAC.h via the setting of kOctaveZero. I've got a 2OC here, so I'll test this this weekend.

mathomas commented 5 years ago

Thank you for your contribution. This looks good, and I'll probably integrate it shortly.

Please note that negative values should be prevented in OC_DAC.h via the setting of kOctaveZero. I've got a 2OC here, so I'll test this this weekend.

Sounds good. I did some testing with my CV adjustment code (obviously very similar to the pulse adjustment here). On intrinsically unipolar stuff like EGs, things look good. Unfortunately, I do see basically “half rectified” waves, say with the LFOs, which supports what you say WRT bipolar. On Buchla, I’d need to bias/offset the waves to fit into 0-10v (if we want the entire waveshape, which I think we do). Haven’t figured that out completely yet, and am probably just confused, or am measuring incorrectly, or both.