Hemisphere Suite Support

The Vector LFO goes down to .10Hz. You can get pretty slow modulations with LowerRenz.

Yeah, the next version will be based on Tom Moxen’s Spoken Into the Void board, which plugs into a uOC’s Teensy pins, replacing the Teensy 3.2 with a 3.5 or 3.6. In addition to more memory, it’ll also allow audio processing and potentially better MIDI support. I’m hoping to get started on this over the summer.


Sorry if this is a offtopic but is there a one place where all o_c and hemisphere related functions are documented? I toyed with developing for o_c hemisphere (https://youtu.be/CcotLurs4es here is a small harmonizer created by modifying DualQuantizer) and it was very easy to start due to good documentation related to flashing firmware but I couldn’t find a complete API reference.


Not offtopic at all. The only documentation I wrote is end-user documentation (https://github.com/Chysn/O_C-HemisphereSuite/wiki), so there’s no real API reference. It looks like you’ve gotten by pretty well, though, that’s a nice harmonizer!

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That harmonizer is awesome, would love to see that in the suite!

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Thanks for your kind words! I will put it on github but I need to clean it up a little first and I would also like to add possibility to define voices offset by user (so for example the second voice could be offseted by 1 scale step and the third voice by 4 steps). But if you want to play with it already here is a hex file that should contain the latest hemisphere suite with DualQuantizer replaced with harmonizer (called TriadChord):
o_c_REV.ino.hex (715.0 KB)
Pitch input is CV1 and harmonized voices are in output 1 and 2.
You can install it using method A from documentation: https://ornament-and-cri.me/firmware/
pushed first draft of harmonizer here (I definitely need a refresher on C++): https://github.com/kfirmanty/O_C-HemisphereSuite


me too, I consider O_C one of my best purchase, Hemisphere move it to next level… Thanks for your works @chysn

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Tried to load current Hemispheres compiled from source today. Screen would not light up.

Re-loaded from the current release Hex file and things worked just fine.

Is there something up with the current state of the source code on Github?

looks cool. question: are the harmonized voices quantized to the selected mode or scale? So say Ionian is selected and a D note is fed to the pitch CV what notes would be output from 1 and 2? Just trying to understand how this app works…

It should work fine, here is a release https://github.com/kfirmanty/O_C-HemisphereSuite/releases/tag/HSKFv1.7C that I loaded into o_c and it worked fine but I can verify it later if the hex file also doesn’t work. As far as I know the o_c that I have is not a modified one so it should probably work the same in all of them.
@ohm: The earlier version quantized notes to the third and fifth above the passed note according to scale. So for example if scale was Ionian and D was fed the CV1 would be F and CV would be A. But the version that I posted to github allows to select offset in scale steps so for example you could set that CV1 is voice 2 scale steps away and CV2 is 4 scale steps away.

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ok that’s what I thought. It is similar to how Braid’s Renascence firmware new chord mode works. Which I’ve been really liking. Great to have something like that in O_C!


I try to ensure that it’s semi-stable before doing commits, so it should work okay. I just tested with the repo head, and 1.8RC is running OK.

Make sure that the build options are correct (Board Teensy 3.2/3.1, USB Type MIDI, Clock 120MHz, Optimize Faster), and that you’re using Arduino IDE 1.8.1 and Teensyduino 1.35. The O_C hardware can behave unpredictably if you use different (older or newer) versions.

Ooooh… those versions are really old and that probably explains it.

There’s some big midi changes in 1.8.5 and then new stuff I need in teensyduino 1.45 that I need for other projects so I can’t really revert back to 1.8.1

If I may suggest - please put those requirements somewhere in the readme or the wiki pages.

FWIW - I can compile the current O_C source with no problems (w/ Arduino 1.8.8 and teensyduino 1.45)

Yeah, compilation usually isn’t the problem. The problem comes in actually running it. It might work, and it might seem stable, even for hours at a time. For a long time I was thinking, “No, they’re crazy, everything’s fine,” until it wasn’t.

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As a saturday afternoon past time I have created another hemisphere app based on HEM_Calculate app and inspired by Teenage Engineering Punch In Effects.
Basically main idea was to perform simple operations on two CV inputs:
Add, Subtract
Multiplicate, Divide
Logic And, Logic Or
Modulo, Logic XOR
Both CV inputs are treated as arguments to those operations and result of each operation from pair is sent to separate output (so signals from both operations can then be mixed using other modules). To prevent the hard clipping before sending to output the operation result is wavefolded.
The operators pair is selected by treating Gate1 and Gate2 as binary number which allows to sequence effect changes using external modules.
The result sounds very digital, there is a lot of aliasing and my normalization function is kind of broken but to be honest I really like how it sounds on droning sound sources.
Here is a bunch of demos:

Dry signal is connected to CV1 and lfo from Befaco Rampage is connected to CV2. Throught all demos the signal connected to CV1 was not modified I was only changing parameters on Befaco Rampage.
In sequenced effects demo I used Monome Teletype to change effects at random.
If someone would like to experiment with this code further the app can be found here:


Sounds really cool! I wasn’t aware there was any more space within Hemisphere to add any new apps - did you have to get rid of something else to add this one?

Unfortunately hemispheres is packed as it is (I think there is less than 1% memory left) so unfortunately I had to delete two apps :< I think it should be possible to create a “installer” were you could choose which apps you want to have in your hemispheres hex file but I haven’t tried to code anything.

I’ve built a bunch of modules but don’t really understand EE well enough to know, but it seems like the Teensy 4 could be a pretty huge upgrade for the O&C as far as computing power and storage both. It would be awesome if the platform evolved into an even more “pluggable” environment where it was easy to customize & share / install new apps via a web-firmware-builder or the like…

@chysn would you care to share your hopes and dreams for the platform, or a platform like it, if any? What are you working on these days? :slight_smile:

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Teensy 4 is a huge upgrade, but it’s not compatible with the O_C hardware. It would require extensive hardware and software modifications to get it to work. Last I heard, the O_C developers had pretty much thrown in the towel on it, as an “upgrade” to O_C.

What am I working on these days? Something silly. I’m building a MIDI and CV interface that can be driven by BASIC code running on a 35-year-old series of Sharp pocket computers. The end result, I think, will be something vaguely Teletype-ish.


I think it should be possible to create a “installer” were you could choose which apps you want to have in your hemispheres hex file but I haven’t tried to code anything.

Yeah, totally. From a technical standpoint, it’s a very straight-forward project. Insert HEM_*.ino files into the code and lines into the configuration file, based on user selections in a web-based interface. It would just be tedious. It bores me to even think about building that kind of system. Especially for the no money that’s involved :slight_smile:


Very cool! Look forward to seeing what you come up with. Too bad about the Teensy upgrade, such a great platform.