SO small Quantizer, 2channel, 5cm

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Hey! I finally managed to get the firmware for my quantizer working! It is basically the kassutronics quantizer (also here already in Kosmo format by @BenRufenacht ) But I wanted something smaller with a simpler interface. What took me so long was that the adc in the kassutronics design runs in free mode, meaning that it samples at a certain freqeuncy and then fires interrupts whenever there is new data. And this cycles through 4 ADC inputs. In my case I needed two additional analog inputs for my potentiometers, so I had to understand how this works first. I had to slow down the conversion frequency a bit, but I think it still works.
The bias knob adds some voltage to the input, which ‘transposes’ the input, but still in key. It can add or subtract up to 12 semitones, 12 o clock position is 0. You same applies for the bias CV inputs. I think you can have nice variations of a main melody if you add a second (slower clocked) sequencer there.

quantizer_photo
quantizer_photo1509×3691 275 KB

It still lacks some more scales and I am currently a bit at a loss at how to make them.
This is the code, first column are the bits for the semitones and the second column is the corresponding LED pattern. Chromatic is clear, all bits are set, but for the other I can not really remember. Could someone point me to a good resource to help me with my music theory? :slight_smile: I mean, in theory I know it’s easy, a major scale is “whole, whole, half, whole, whole, whole, half”, but I am having trouble to connect that to the individual bits, because between some bits there is a half tone step and between others not? or maybe not? Whenever I tried it, I made some stupid mistake so far -.- … I would like to add a major pentatonic, harmonic minor, whole tone and diminished for now, if you think I am missing a very important nice sounding scale, please tell me :slight_smile:

// if I understand kassutronic quantizer correctly, 
// only the upper 12 bits are used to define if a semitone is in the scale
// the led pattern is written directly to the PORT of outputs
definedScale possibleScales[5] = {
  {0b1111111111110000, B11111100},  // chromatic
  {0b1010110101010000, B00000100},  // major
  {0b1010010110110000, B00001000},  // minor
  {0b1000000000000000, B10000100},  // only octaves
  {0b1010010110110000, B10001000},  // minor pentatonic

};

Here is the github with kicad and firmware files, I hope I have not forgotten anything in there.

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do you know this one?
search for quantizer inside the page.

http://www.acxsynth.com/archives/archives.html

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Translating the 12 first bits (from left to right) into notes:

# Chromatic (twelve-tone scale)
0b 1  1  1  1  1  1  1  1  1  1  1  1  0000
   C  C# D  D# E  F  F# G  G# A  A# B

# C Major:
0b 1 0 1 0 1 1 0 1 0 1 0 1 0000
   C   D   E F   G   A   B

Find below a list of scales including their Integer notation. These can be easily translated into the above bit-scheme. Just set the bits on the nth positions:

# Chromatic (0,1,2,3,4,5,6,7,8,9,10,11)
0b 1 1 1 1 1 1 1 1 1 1 1  1 0000
   ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^  ^
   0 1 2 3 4 5 6 7 8 9 10 11

# Major scale (0,2,4,5,7,9,11)
0b 1 0 1 0 1 1 0 1 0 1 0  1 0000
   ^   ^   ^ ^   ^   ^    ^
   0 1 2 3 4 5 6 7 8 9 10 11
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