Xmas sequencer

Xmas/Xmas.ino

@@ -0,0 +1,112 @@
+// Basic demo for configuring the MCP4728 4-Channel 12-bit I2C DAC
+#include <Adafruit_MCP4728.h>
+#include <Wire.h>
+
+Adafruit_MCP4728 mcp;
+
+
+float tuning[13];
+int m1[] = { 0, 5, 5, 7, 5, 4, 2, 2, 2, 7, 7, 9, 7, 5, 4, 0, 4, 9, 9, 10, 9, 7, 5, 2, 0, 0, 2, 7, 4, 5, 0, 5, 5, 5, 4, 4, 5, 4, 2, 0, 7, 9, 7, 7, 5, 5, 12, 0, 0, 0, 2, 7, 4, 5  };
+float d1[] = { 2, 2, 1, 1, 1, 1, 2, 2, 2, 2, 1, 1, 1, 1, 2, 2, 2, 2, 1,  1, 1, 1, 2, 2, 1, 1, 2, 2, 2, 4, 2, 2, 2, 2, 4, 2, 2, 2, 2, 4, 2, 2, 1, 1, 1, 1,  2, 2, 1, 1, 2, 2, 2, 4 };
+float gate = 0.5;
+int bpm = 240;
+float beat_s = 60.0 / (float)bpm;
+int beat_m = round(1000.0 * beat_s); 
+float voltrange = 5.0; 
+float octave = 4096.0 / voltrange; // number of DAC steps in an octave
+float mod_b = 3.141592653589793 / 4.0;
+
+typedef struct {
+  int s = 0;
+  bool noteOn = false;
+  long play = 0;
+  long rel = 0;
+  long last = 0;
+  long init = 0;
+  int *melody;
+  float *duration;
+  int len = 0;
+  MCP4728_channel_t pitch;
+  MCP4728_channel_t gate;
+} sequencer;
+
+sequencer seq1, seq2;
+
+
+void setup(void) {
+  Serial.begin(115200);
+  while (!Serial)
+    delay(10); // will pause Zero, Leonardo, etc until serial console opens
+
+  if (!mcp.begin(0x64)) {
+    Serial.println("Failed to find MCP4728 chip");
+    while (1) {
+      delay(10);
+    }
+    Serial.println("MCP4728 initialised");
+  }
+
+  mcp.setChannelValue(MCP4728_CHANNEL_B, 0);
+
+  float n0 = 0;
+  for( int i = 0; i < 13; i++ ) {
+      tuning[i] = round(n0 + octave * (float)i / 12.0);
+  }
+  long now = millis();
+  seq1.last = now;
+  seq1.pitch = MCP4728_CHANNEL_A;
+  seq1.gate = MCP4728_CHANNEL_B;
+  seq1.melody = m1;
+  seq1.duration = d1;
+  seq1.len = sizeof(m1) / sizeof(m1[0]);
+  Serial.println("length of seq 1 pattern");
+  Serial.println(seq1.len);
+
+//  seq2.last = now;
+//  seq2.pitch = MCP4728_CHANNEL_C;
+//  seq2.gate = MCP4728_CHANNEL_D;
+
+}
+
+
+void loop() {
+  long now = millis();
+  runSequencer(seq1, now);
+  Serial.println(seq1.noteOn);
+}
+
+void runSequencer(sequencer seq, long now) {
+  if( seq.noteOn ) {
+    if( now - seq.last > seq.rel ) {
+      Serial.println("off");
+      noteOff(seq);
+      seq.last = now;
+      seq.play = round(beat_m * seq.duration[seq.s] * (1.0 - gate));
+      seq.noteOn = false;
+      seq.s += 1;
+      if( seq.s > seq.len ) {
+        seq.s = 0;
+      }
+    }
+  } else {
+    if( now - seq.last > seq.play ) {
+      noteOn(seq, seq.melody[seq.s]);
+      seq.last = now;
+      seq.rel = round(beat_m * seq.duration[seq.s] * gate);
+      seq.noteOn = true;
+    }
+  }
+  
+}
+
+
+void noteOn(sequencer seq, int note) {
+  if( note > -1 ) {
+    mcp.setChannelValue(seq.pitch, tuning[note]);
+    mcp.setChannelValue(seq.gate, 4095);
+  }
+}
+
+void noteOff(sequencer seq) {
+    mcp.setChannelValue(seq.gate, 0);
+}