Making Pulse


Pulse is my first MIDI sequencer!


I use Elektron Model: Samples to perform for my Laptop Ensemble class.



It’s a great little thing for music production but it lacks in performance features. It would be awesome to add a module to manipulate its sequences in a more varied and dynamic way on the fly. Enter Euclidean Rhythms!


Euclidean Rhythms are the most dynamic way of creating drum sequences I’ve seen. Basically, it is a simple algorithm that takes in the total number of notes in a sequence and the number of ON notes, and spreads them out as equally as possible. Here’s how it looks:



I’m planning to make a tangible version of that and use it with my drum machine and synthesizers.


Early prototyping:


Components:

  1. Rotary Encoder
  2. Capacitive Touch Plate (under surface)
  3. Push Buttons
  4. LEDs (under surface)
  5. USB-in for MIDI
  6. Power-in
  7. Glass surface
  8. Wooden frame



A lot of coding.





1. Inputs modules



2. Sequencer



3. MIDI



I thought I figured out midi by just using a few libraries that somehow worked with samd21 but I later realized there’s still much more to learn.


Finalizing user interface layout


I started by re-making layout out the user interface.



Parts selection


I selected the best parts. I wanted it to tingle when you touch these knobs. So you can try and confirm it’s a really pleasant feel.



PCB milling


Then the pcb milling time came. I had to use a large 8x5 board which meant I couldn’t use any milling machines except for this one. It’s giving mystery and rawness. So I spent a few days learning it. There’s been plenty of mistakes. Like 4 hours debugging the silent z limit hit, which almost got me insane. Or wrong parameters which resulted in spaghetti pcb. Regardless, I wrote a tutorial on how to use it and now this machine is my bestie. If the board holes are too small, just drop it it, reset the zs and x and ys. And you can also do cool stuff because the input into the system is a png, which is what you can see I made on my front cover.




Prototyping front panel





Case with sheet metal


Then was the case. I built a metal case, sandblasted, and painted black to go along with the ui.







Final day oopsies:


Things go wrong:

  1. Midi is tough
  2. LEDs are insanely tough



Minor notes: Don’t




Epilogue.