26Slew/26Slew.ino

@@ -1,170 +0,0 @@
-// Better sequencer which uses interrupts
-
-#include <Adafruit_MCP4728.h>
-#include <Wire.h>
-
-Adafruit_MCP4728 mcp;
-
-
-float tuning[37];
-float voltrange = 4.85;  // measured this, probably not accurate
-float octave = 4096.0 / voltrange; // number of DAC steps in an octave
-
-
-// melody
-
-// int pitch[] = { 4, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-// -1, -1, -1, -1, -1, -1, -1, -1,-1, -1, -1, -1,2, -1, -1, -1, };
-// int dur[] = { 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-//             0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0,  };
-
-// hi hat
-
-int pitch[] = { 1, 3, 4, 10, 6, 3, 11, -1 };
-float dur[] = { 1,0.5,0.5,0.5,0.5,0.5,0.5,0.5,0.5, };
-
-
-int note = 0;
-int phrase = 8;
-
-int s;
-int bpm = 120;
-float beat_s = 60.0 / (float)bpm;
-float beat_m = 1000.0 * beat_s; 
-bool noteon = false;
-int beat = false;
-long notestart, notedur, barstart;
-int target, slew;
-float slewk = 0.005;
-
-void setup() {
-  Serial.begin(115200);
-
-  float freq = (float)bpm / 60.0;
-
-  int ocr = round(16000000.0 / (1024.0 * freq )) - 1;
-  Serial.println(ocr);
-  if( ocr < 65536 ) {
-
-    cli();
-
-    TCCR1A = 0;// set entire TCCR1A register to 0
-    TCCR1B = 0;// same for TCCR1B
-    TCNT1  = 0;//initialize counter value to 0
-    OCR1A = ocr; //ocr; 
-    // turn on CTC mode
-    TCCR1B |= (1 << WGM12);
-    // Set CS10 and CS12 bits for 1024 escaler
-    TCCR1B |= (1 << CS12) | (1 << CS10);  
-    // enable timer compare interrupt
-    TIMSK1 |= (1 << OCIE1A);
-
-    sei();
-
-  } else {
-    Serial.println("BPM out of range");
-  }
-
-  if (!mcp.begin(0x64)) {
-    while (1) {
-      delay(100);
-    }
-  }
-
-  // randomSeed(analogRead(A0));
-  mcp.setSpeed(800000L);
-  make_tuning(12);
-  note=0;
-  slew=0;
-  barstart=millis();
-}
-
-void make_tuning(int edo) {
-  float n0 = 0;
-  float edof = (float)edo;
-  for( int i = 0; i < 37; i++ ) {
-      tuning[i] = round(n0 + octave * (float)i / edof);
-  }
-
-}
-
-
-// mod_note argument is milliseconds from the start of last note
-float mod_note(int x) {
-  float xb = x / (0.2 * beat_m);
-  return 0.5 + 0.5 * xb * (xb - 1) * ( xb - 2);
-}
-
-// mod_note argument is milliseconds from the start of this bar
-float mod_bar(int x) {
-  return 0.5 + 0.5 * sin((float)x / (beat_m * 2));
-}
-
-void set_mod(MCP4728_channel_t channel, float v) {
-  int o;
-  o = round(v * 4095.0);
-  if( o > 4095 ) {
-    o = 4095;
-  }
-  if( o < 0 ) {
-    o = 0;
-  } 
-  mcp.setChannelValue(channel, o);
-}
-
-ISR(TIMER1_COMPA_vect){ // called once every beat
-  beat = true;
-}
-
-
-void loop() {
-  float mod;
-  int o;
-  long now = millis();
-  if( beat ) {
-    beat = false;
-    if( pitch[s] > -1 ) {
-      notestart = millis();
-      notedur = round(beat_m * dur[s]);
-      noteOn(pitch[s]);
-      noteon = true;
-    }
-    s += 1;
-    if( s == phrase ) {
-      s = 0;
-      barstart = notestart;
-    }
-  } else {
-    if( noteon ) {
-        set_mod(MCP4728_CHANNEL_C, mod_note(now - notestart));
-      if( now - notestart > notedur ) {
-        noteOff();
-        noteon = false;
-      }
-    }
-    set_mod(MCP4728_CHANNEL_D, mod_bar(now - barstart));
-    slew += round((float)(target - slew) * slewk);
-    if( slew > 4095 ) {
-      slew = 4095;
-    }
-    if( slew < 0 ) {
-      slew = 0;
-    }
-    mcp.setChannelValue(MCP4728_CHANNEL_A, slew);
-  }
-}
-
-
-void noteOn(int note) {
-  if( note > -1 ) {
-    //mcp.setChannelValue(MCP4728_CHANNEL_A, tuning[note]);
-    target = tuning[note];
-    mcp.setChannelValue(MCP4728_CHANNEL_B, 4095);
-  }
-}
-
-void noteOff() {
-    mcp.setChannelValue(MCP4728_CHANNEL_B, 0);
-}
-
-

README.md

@@ -99,27 +99,5 @@ reverb
 
 Using the Fibonacci series modulo n, also known as the (Pisano period)[https://en.wikipedia.org/wiki/Pisano_period], as a wavetable, and incrementing n for each note in the sequence
 
-### 21 Jacob's Ladder
 
-Deliberate FM synthesis by using a wavetable as the control voltage of a VCO
 
-### 22 Onomatopoeia
-
-Triggering LFO patterns from the sequencer
-
-### 23 Ha Ha
-
-Using the triggering stuff from 22 to build a track with more structure
-
-### 24 Wander
-
-Another 7TET piece using the sequencer
-
-### 25 Ribosome
-
-Using the sequencer to trigger envelopes and LFOs at two scales - notes and
-bars
-
-### 26
-
-Basic slew / portamento