# AO G.E.A.R. Sequencer (rhythm generator) **URL:** \ **Category:** KOSMO MODULES\ **Created:** [December 4, 2021, 12:53am UTC](https://lookmumnocomputer.discourse.group/t/ao-g-e-a-r-sequencer-rhythm-generator/4332 "2021-12-04T00:53:32Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![analogoutput](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/analogoutput/32/29663_2.png) [@analogoutput](https://lookmumnocomputer.discourse.group/u/analogoutput)\ **Post date:** [December 4, 2021, 12:53am UTC](https://lookmumnocomputer.discourse.group/t/ao-g-e-a-r-sequencer-rhythm-generator/4332/1 "2021-12-04T00:53:32Z")
This is a voltage controlled trigger sequencer or, perhaps a better term, trigger sequence generator. It can function as a Euclidean rhythm generator, but it can also create other rhythms via different means. It is designed in Kosmo format, though it can presumably be adapted to any other format capable of supplying enough positive voltage for 5 V voltage regulators. ## What it does Rather than sending triggers in a sequence that is completely specified by the user, the G.E.A.R. Sequencer creates sequences based on user specified parameters. It offers a choice of four algorithms: - **G** ap sequence - **E** uclidean sequence - **A** DC sequence - **R** andom sequence (Hence the name G.E.A.R. Sequencer.) Each algorithm is governed by up to four parameters whose values the user can dial in on potentiometers, or they can be set and dynamically altered using control voltages. Within limits of program memory and programmer sanity, there is no reason more algorithms could not be added, but these are the four implemented so far. ## Algorithms **Euclidean sequencing** is familiar and I won’t go into the details here — see [http://cgm.cs.mcgill.ca/~godfried/publications/banff-extended.pdf](http://cgm.cs.mcgill.ca/~godfried/publications/banff-extended.pdf) if you need them. The sequence pattern is determined by two parameters: Repetition period (_P_) and number of triggers (_T_). The algorithm distributes the _T_ triggers as uniformly as possible among the _P_ sequence steps. A third parameter, the offset (_O_), governs not the pattern itself but where the pattern starts/stops relative to where the period starts/stops. A more novel algorithm is the **gap sequence,** based on the procedure underlying linear scales in tuning theory and the [Three-gap Theorem](https://en.wikipedia.org/wiki/Three-gap_theorem) in mathematics — not that you need to know that. I’m not aware of any prior use of this idea for trigger sequencing although I would be quite surprised if no one else has done it before. In a gap sequence the pattern is defined by three parameters: _P_, _T_, and the generator (_G_). For a given _P_ and _T_ there is exactly one Euclidean sequence, but there are up to _P_/2 gap sequences corresponding to different generators. Again, the position of the sequence start relative to the period can be specified by _O_. You can find details of the algorithm [here](https://github.com/holmesrichards/gearseq/blob/main/Docs/gap_sequence.md). An **ADC sequence** uses a pattern based on digitization of an analog control voltage. You specify _P_ and a value to digitize, _V_, as well as, again, _O_. The sequence pattern is the first _P_ bits in the digitization of _V_. This is similar to something the Barton Musical Circuits BMC006 Voltage To Rhythm Converter does (though the BMC006 does a lot more with the idea). A **random sequence** is fairly self explanatory. For a given _P_ and _T_, the algorithm distributes _T_ triggers randomly within _P_ steps. The random pattern is then repeated indefinitely, offset by _O_ as with the other types, until a new sequence is requested. Another “parameter” is the throw (_Th_). The value of the throw is not used to determine the pattern, but if it changes, a new random pattern will be chosen. ## Photos ![front](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/3X/e/3/e313ab1447f8c80287dde5cd18130fe99fd0bf93.jpeg) ![back](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/3X/1/c/1cd61f5ae421845fb45933fb5cef747c501acc73.jpeg) ## Demo [![](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/3X/d/9/d9288468854f1dba310f8ab5d88dfb8ceb4d119c.jpeg "G.E.A.R. Sequencer demo") ](https://www.youtube.com/watch?v=Uje1tHly1V0) ## Documentation - [Schematic](https://github.com/holmesrichards/gearseq/blob/main/Docs/gearseq.pdf) - PCB layout: [front](https://github.com/holmesrichards/gearseq/blob/main/Docs/gearseq_layout_front.pdf), [back](https://github.com/holmesrichards/gearseq/blob/main/Docs/gearseq_layout_back.pdf) - [BOM](https://github.com/holmesrichards/gearseq/blob/main/Docs/gearseq_bom.md) - [Build notes](https://github.com/holmesrichards/gearseq/blob/main/Docs/build.md) - [Implementation details](https://github.com/holmesrichards/gearseq/blob/main/Docs/implementation.md) - [Gap sequence algorithm](https://github.com/holmesrichards/gearseq/blob/main/Docs/gap_sequence.md) - [Usage notes](https://github.com/holmesrichards/gearseq/blob/main/Docs/usage_notes.md) ## GitHub repository Schematics, KiCad design files, Gerbers, docs here: - [https://github.com/holmesrichards/gearseq](https://github.com/holmesrichards/gearseq) * * * A few extra boards and panels will be available on Tindie fairly soon. ---
**Author:** ![Kelaifu](https://avatars.discourse-cdn.com/v4/letter/k/46a35a/32.png) [@Kelaifu](https://lookmumnocomputer.discourse.group/u/Kelaifu)\ **Post date:** [December 4, 2021, 5:31am UTC](https://lookmumnocomputer.discourse.group/t/ao-g-e-a-r-sequencer-rhythm-generator/4332/2 "2021-12-04T05:31:50Z")
Woah, you’re going to challenge Hagiwo for output at this rate! ---
**Author:** ![TimMJN](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/timmjn/32/15227_2.png) [@TimMJN](https://lookmumnocomputer.discourse.group/u/TimMJN)\ **Post date:** [December 4, 2021, 7:15am UTC](https://lookmumnocomputer.discourse.group/t/ao-g-e-a-r-sequencer-rhythm-generator/4332/3 "2021-12-04T07:15:45Z")
Props for a voltage-controlled trigger sequencer, very cool! ---
**Author:** ![Cyclic](https://avatars.discourse-cdn.com/v4/letter/c/46a35a/32.png) [@Cyclic](https://lookmumnocomputer.discourse.group/u/Cyclic)\ **Post date:** [December 6, 2021, 8:12pm UTC](https://lookmumnocomputer.discourse.group/t/ao-g-e-a-r-sequencer-rhythm-generator/4332/4 "2021-12-06T20:12:08Z")
Hey, this does look very interesting. I would be interested in a pcb… ---
**Author:** ![Sonosus](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/sonosus/32/13679_2.png) [@Sonosus](https://lookmumnocomputer.discourse.group/u/Sonosus)\ **Post date:** [December 6, 2021, 8:23pm UTC](https://lookmumnocomputer.discourse.group/t/ao-g-e-a-r-sequencer-rhythm-generator/4332/5 "2021-12-06T20:23:11Z")
(@analogoutput your github link on the post is broken, just sayin 😊) ---
**Author:** ![Cyclic](https://avatars.discourse-cdn.com/v4/letter/c/46a35a/32.png) [@Cyclic](https://lookmumnocomputer.discourse.group/u/Cyclic)\ **Post date:** [December 7, 2021, 8:23am UTC](https://lookmumnocomputer.discourse.group/t/ao-g-e-a-r-sequencer-rhythm-generator/4332/6 "2021-12-07T08:23:03Z")
Have you got a better video to demo it for us? Id like a talk through and demo of each algorithm, even if its a 20minute indulgence… ---
**Author:** ![analogoutput](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/analogoutput/32/29663_2.png) [@analogoutput](https://lookmumnocomputer.discourse.group/u/analogoutput)\ **Post date:** [December 7, 2021, 12:48pm UTC](https://lookmumnocomputer.discourse.group/t/ao-g-e-a-r-sequencer-rhythm-generator/4332/7 "2021-12-07T12:48:41Z")
There’ll be one eventually. I have several videos to do, but I keep putting other things first. ---
**Author:** ![analogoutput](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/analogoutput/32/29663_2.png) [@analogoutput](https://lookmumnocomputer.discourse.group/u/analogoutput)\ **Post date:** [January 2, 2022, 5:10am UTC](https://lookmumnocomputer.discourse.group/t/ao-g-e-a-r-sequencer-rhythm-generator/4332/8 "2022-01-02T05:10:49Z")
Video’s up! [![](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/3X/e/3/e31ad91f18f3d04737273517672c1763dfa0d3c3.jpeg "G.E.A.R. voltage controlled rhythm sequencer") ](https://www.youtube.com/watch?v=5tlJ_KqMPUQ) And a supplementary video about the gap algorithm: [![](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/3X/f/c/fc0307f5624b2233d6498549d6099bc1b31b6b04.jpeg "Gap sequence algorithm") ](https://www.youtube.com/watch?v=vyK-IkU6jMs) (second video re-uploaded to correct title) ---
**Author:** ![TimMJN](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/timmjn/32/15227_2.png) [@TimMJN](https://lookmumnocomputer.discourse.group/u/TimMJN)\ **Post date:** [January 2, 2022, 8:45am UTC](https://lookmumnocomputer.discourse.group/t/ao-g-e-a-r-sequencer-rhythm-generator/4332/9 "2022-01-02T08:45:40Z")
Nice work!! I’ll think about including the gap algorithm on my euclidean generator 🤔🤔 PS I think you forgot to change the title screen on that video 😉 ---
**Author:** ![Dud](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/dud/32/610_2.png) [@Dud](https://lookmumnocomputer.discourse.group/u/Dud)\ **Post date:** [January 2, 2022, 1:38pm UTC](https://lookmumnocomputer.discourse.group/t/ao-g-e-a-r-sequencer-rhythm-generator/4332/10 "2022-01-02T13:38:23Z")
Really cool ! i project to make one one day 🙂 thx for sharing ! ---
**Author:** ![ChristianBloch](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/christianbloch/32/56_2.png) [@ChristianBloch](https://lookmumnocomputer.discourse.group/u/ChristianBloch)\ **Post date:** [January 4, 2022, 8:50pm UTC](https://lookmumnocomputer.discourse.group/t/ao-g-e-a-r-sequencer-rhythm-generator/4332/11 "2022-01-04T20:50:42Z")
Imma have to give this one the Eurorack treatment. Really nice idea and execution! ---
**Author:** ![analogoutput](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/analogoutput/32/29663_2.png) [@analogoutput](https://lookmumnocomputer.discourse.group/u/analogoutput)\ **Post date:** [January 4, 2022, 9:49pm UTC](https://lookmumnocomputer.discourse.group/t/ao-g-e-a-r-sequencer-rhythm-generator/4332/12 "2022-01-04T21:49:18Z")
Should be very doable, the Kosmo PCB’s pretty sparse! Keep us posted! ---
**Author:** ![ChristianBloch](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/christianbloch/32/56_2.png) [@ChristianBloch](https://lookmumnocomputer.discourse.group/u/ChristianBloch)\ **Post date:** [January 4, 2022, 10:24pm UTC](https://lookmumnocomputer.discourse.group/t/ao-g-e-a-r-sequencer-rhythm-generator/4332/13 "2022-01-04T22:24:04Z")
I’m sure it will be in my JLCPCB cart by the weekend 🙂 ---
**Author:** ![ChristianBloch](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/christianbloch/32/56_2.png) [@ChristianBloch](https://lookmumnocomputer.discourse.group/u/ChristianBloch)\ **Post date:** [January 16, 2022, 8:22pm UTC](https://lookmumnocomputer.discourse.group/t/ao-g-e-a-r-sequencer-rhythm-generator/4332/14 "2022-01-16T20:22:44Z")
![PCB Prototype & PCB Fabrication Manufacturer - JLCPCB](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/3X/3/d/3d76d33d5cd81034edcb333cfed383dedd4bb23c.png) ---
**Author:** ![ChristianBloch](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/christianbloch/32/56_2.png) [@ChristianBloch](https://lookmumnocomputer.discourse.group/u/ChristianBloch)\ **Post date:** [January 19, 2022, 6:59pm UTC](https://lookmumnocomputer.discourse.group/t/ao-g-e-a-r-sequencer-rhythm-generator/4332/15 "2022-01-19T18:59:54Z")
It’s here, it works, but I still need to get the screens. I was able to test it with one I have with a different pinout. EDIT: Just realized that I can probably change the pinout in the software… EDIT, EDIT: Actually no, since it’s the power pins that are different. I am very pleased with this one. Thanks @analogoutput for the great idea! ![image](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/3X/5/d/5de63f9dedd24026e0a2bb7bc4fc87eea0369f01.jpeg) ![image](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/3X/3/d/3d75dc79816e2976098d9e91ec3c8672e54d3134.jpeg) ![image](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/3X/d/0/d0e7aadecb9e7d4404e19562099df17b9e7d708a.jpeg) ![image](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/3X/6/b/6bb736ad0f3ba09d1b884dd5100c2514dfbfc3a4.jpeg) ![image](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/3X/d/e/de756a5e1ca1d380e92fd4f5b463f9ca8d7d4baf.jpeg) ![image](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/3X/4/3/4356a494eb521c6bd7cd13af2b567c2cfa0b164e.jpeg) ---
**Author:** ![JUXTAPOZ74](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/juxtapoz74/32/523_2.png) [@JUXTAPOZ74](https://lookmumnocomputer.discourse.group/u/JUXTAPOZ74)\ **Post date:** [January 19, 2022, 7:26pm UTC](https://lookmumnocomputer.discourse.group/t/ao-g-e-a-r-sequencer-rhythm-generator/4332/16 "2022-01-19T19:26:49Z")
Wow that’s awesome! Looks great! ---
**Author:** ![analogoutput](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/analogoutput/32/29663_2.png) [@analogoutput](https://lookmumnocomputer.discourse.group/u/analogoutput)\ **Post date:** [January 19, 2022, 8:52pm UTC](https://lookmumnocomputer.discourse.group/t/ao-g-e-a-r-sequencer-rhythm-generator/4332/17 "2022-01-19T20:52:13Z")
> [@ChristianBloch](#): > > EDIT, EDIT: Actually no, since it’s the power pins that are different. Part of why I did mine like this: ![image](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/3X/4/9/49269a88df4d8551c0516c909a4991eb3ce086d7.jpeg) Yours looks great! ---
**Author:** ![popflier](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/popflier/32/80_2.png) [@popflier](https://lookmumnocomputer.discourse.group/u/popflier)\ **Post date:** [January 20, 2022, 8:32am UTC](https://lookmumnocomputer.discourse.group/t/ao-g-e-a-r-sequencer-rhythm-generator/4332/18 "2022-01-20T08:32:53Z")
Well stranger…nice to see you again. 🙂 I would be interested in one of your Eurorack versions if you have a spare pcb/panel handy? I could also use a couple more of your bus boards 🙂 ---
**Author:** ![ChristianBloch](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/christianbloch/32/56_2.png) [@ChristianBloch](https://lookmumnocomputer.discourse.group/u/ChristianBloch)\ **Post date:** [January 20, 2022, 7:31pm UTC](https://lookmumnocomputer.discourse.group/t/ao-g-e-a-r-sequencer-rhythm-generator/4332/19 "2022-01-20T19:31:02Z")
Hi there! I have an improved version of the bus boards coming and I will have the G.E.A.R. Ready for sale some time next week. I’ll let you know. ---
**Author:** ![ChristianBloch](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/christianbloch/32/56_2.png) [@ChristianBloch](https://lookmumnocomputer.discourse.group/u/ChristianBloch)\ **Post date:** [January 20, 2022, 7:32pm UTC](https://lookmumnocomputer.discourse.group/t/ao-g-e-a-r-sequencer-rhythm-generator/4332/20 "2022-01-20T19:32:56Z")
I was able to find a screen locally, though not a bicolor one, while I wait for the rest to turn up. Here’s a few pics of the assembled module: ![image](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/3X/c/5/c5353260ab2d184befb722a85672a228440176b9.jpeg) ![image](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/3X/b/3/b368dbd226735498097f60c8490694cf1d445508.jpeg) ![image](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/3X/d/e/de6345873e93cb650c0394d8deb614f8beea1fd5.jpeg) [Next page](https://lookmumnocomputer.discourse.group/t/ao-g-e-a-r-sequencer-rhythm-generator/4332.md?page=2)