in DIY

Here’s Bjorklund. He’s been dropped, stood-on and attacked by cats, yet survives. I was pissed drunk when I made this but hopefully it will provide a first inkling of the little fella’s potential:



Euclid’s algorithm (circa 300 BC) describes a method for computing the greatest common divisor (GCD) of two integers. It is one of the oldest numerical algorithms still in common use.

In 2003 Eric Bjorklund extended the Euclidean algorithm to address timing issues in Neutron Accelerators. He wanted to solve the following problem:

‘distribute n pulses over m โ€œtiming slotsโ€ in the most even way possible, even though n may not necessarily be an even divisor of m.’


In 2004, Godfried Toussaint demonstrated that the resulting binary patterns mirrored many familiar ostinatos (repeating rhythmic phrases) heard in diverse range of musical styles.
African rhythms are well represented and, naturally, have since appeared in South American music, modern jazz, pop, rock and dance.


Bjorklund is a Bjorklundean sequencer.

8 independent tracks, each with their own:

– Tracklength of 1- 64 steps
– 1-64 Pulses, feeding into the algorithm.
– Full control over current playback position (rotation).
– Clock dividers (Whole note to 1/32 ).
– Solo/Mute.
– Velocity.
– Random Velocity offset – Humanisation (+/-)
– Accented notes every 1-16 steps (max velocity)
– Assignable MIDI Note.
– Assignable MIDI Channel.
– Randomization per track or all tracks.

Fine control over Master BPM (+/- 3, 1, 0.1).

Next version will bump-up to Teensy 3.1 and will feature…
Performance Controls
Groove – Tick Quantization and Tick shift
Extensive preset management and fast switching
Track groupings
Proximity sensors/D-beam
Tap Tempo

Apologies for the shitty video quality. But does it matter?

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  1. Waooh, really impressed by this and all your work!!!
    Where do you find the time, do you sleep? ๐Ÿ™‚
    The Shruthi mods are great as well, I also did a SMR MKII but without mods, and I have pcb and chips for the 4Pole and the Lp2+delay, but I still have to find components and time to build them…I will check to add some mods it looks great indeed!!!
    Take care and have fun!!!

  2. Hi Brice,

    Thanks for your nice words ๐Ÿ™‚

    In short, the only reason I have time is that ‘normal’ business is very slow at the moment. I’ve been slowly building-up a stock of components for about two years, and I have quite a few unfinished wrap-up. I have a ‘biggie’ coming soon. Watch for it….

  3. It’s been ages since you suggested a biggie coming and mentioned the schematics for the matrices. Also I’d love to be able to do the 16×8 matrix to follow all the lines of rhythm on a LED matrix (they’re in the post as I speak). Any pics of circuits or whatever so I can have a go please? I have Shruthi to build, the parts for a Sonic Potions LXR have come too and to be able to make a special case say for the Shruthi and incorporate the matrix – that would be totally cool

    • Paul,

      Thanks for your note. I’ve been unable to finish this as expected due to being totally overwhelmed by the daily grind.
      Since you are the fist person to bug me about it, I can make an offer: we collaborate to create a PCB. My skills in this area are shit, and I just don’t have the time to learn and experiment as I’d like right now. I can provide everything I have – including the code and the working prototype. I also want to expand it – loads of ideas myself – and even thought it may be commercially viable. If only I had the time….

      Contact me if you wish to proceed: stimresp at gmail

      Thanks again,

      • I’ve never done PCB design, my interest in this is hobby based and I watch YT shorts to learn, Collin thingy who makes amusing but informative videos plus Notes & Volts like in your link. Watched that on breadboarding a few times and others on Arduino programming. I’d be happy to spend time learning though and software for PCB design is out there (Eagle?) and firms or home-hobbyists could make a test run of 5-10 to see how it goes. Even etching a copper board for a test (by a 3rd party) My matrixes are coming from HK and are a lot less than Adafruit or UK suppliers (Maplin etc).

        Hope you didn’t consider my enquiry ‘bugging’ you, just after the time between your writing all this and seeing really keen, I thought you might have developed something further. Work eh – gets in the way all the time!

        Thanks for responding ๐Ÿ™‚


        • Hi Paul,

          I meant ‘bugging’ in the friendliest of ways, I assure you. If people didn’t bug me I’d stay in bed and drink lots of weissbier ๐Ÿ˜›

          I was on the cusp of learning PCB design before I was whisked away to red-eye land. The program I was attempting to use was Fritzung (it’s free and seems popular – google it).

          As it is, the info on this site is correct and, if you have the patience to build your own you should be able to replicate. The scariest part is the LED matrix wiring. There are easier ways, but the matrices are way cooler. I don’t remember where I got mine.

          But yeah, if you really want to got for it I’ve be happy to hand over my prototype for dissection. I’m in Holland – assume you’re UK? I travel to London for work sometimes.

          Mull it over, have a play with Fritzung and , if you’re feeling confident, swing me a mail. I’m doing this for fun, not profit, but it would nice to be able to distribute a PCB at least.