Musically interesting fibo waveforms

Fibomod/Fibomod.ino

@@ -6,12 +6,17 @@
 
 Adafruit_MCP4728 mcp;
 
-#define nsamp 256
+#define nsamp 1500
 #define dacmax 256
 
 unsigned int phase = 0;
-unsigned int fibo = 20;
+unsigned int fibo = 3;
 unsigned int scale = 0;
+unsigned int fibi = 0;
+unsigned int pmax = nsamp;
+
+unsigned int fibosort[] = { 4,3,11,8,29,7,21,19,38,76,5,55,199,6,9,12,16,18,24,36,48,72,144,13,22,31,44,62,124,47,141,17,34,68,136,152,15,33,41,123,165,205,58,116,211,89,139,14,23,28,32,42,46,56,63,69,84,92,96,112,126,138,161,168,184,207,224,252,101,151,233,39,87,59,10,20,40,61,88,110,122,155,220,244,248,71,27,51,54,57,102,107,108,114,153,171,204,214,216,228,37,113,79,158,35,77,105,231,26,52,104,232,43,129,181,209,64,94,188,192,25,53,106,109,212,218,121,49,91,147,203,229,30,45,60,66,80,82,90,93,99,120,132,164,176,180,183,186,198,240,246,131,178,67,201,65,143,145,119,133,189,238,73,149,202,111,235,78,83,117,156,166,174,208,234,249,118,236,179,85,95,170,187,190,191,128,97,75,103,142,81,159,162,74,148,226,177,239,70,115,140,154,160,210,217,230,241,253,251,221,247,127,86,172,137,195,213,219,50,100,200,237,157,163,242,98,167,182,196,173,135,255,169,185,193,197,175,134,130,215,146,223,222,227,125,245,194,150,225,206,243,254,250 };
+
 
 byte waveform[nsamp];
 
@@ -26,7 +31,7 @@ void setup() {
   // set compare match register for 1hz increments
   //OCR1A = 15624;// = (16*10^6) / (1*1024) - 1 (must be <65536)
   //OCR1A = 7812;// = (16*10^6) / (1*1024) - 1 (must be <65536)
-  OCR1A = 10000;
+  OCR1A = 2000;
   // turn on CTC mode
   TCCR1B |= (1 << WGM12);
   // Set CS10 and CS12 bits for 1024 prescaler
@@ -37,6 +42,7 @@ void setup() {
   sei();
 
 
+
   Serial.begin(115200);
 
   if (!mcp.begin(0x64)) {
@@ -50,38 +56,46 @@ void setup() {
   for( int i = 0; i < nsamp; i++ ) {
     waveform[i] = 1;
   }
+  fibo = fibosort[fibi];
+  setwave();
+}
 
+void setwave(){
+  waveform[0] = 0;
+  waveform[1] = 1;
+  fibo = fibosort[fibi];
+  Serial.println(fibo);
+  pmax = nsamp;
+  for (int i=2; i<nsamp; ++i){
+    waveform[i] = (waveform[i - 1] + waveform[i - 2]) % fibo;
+    if( waveform[i - 1] == 0 && waveform[i] == 1 ) {
+      pmax = i - 1;
+      break;
+    }
+  }
+  Serial.println(pmax);
+  float scale = 256 / fibo;
+  for( int i = 0; i < nsamp; ++i ) {
+    waveform[i] *= scale;
+  }
 }
 
 ISR(TIMER1_COMPA_vect){//timer1
-  unsigned int flog;
-  scale = 10;
-  fibo = 3 + analogRead(A0) >> 2;
-  flog = fibo;
-  while( flog ) {
-    flog = flog >> 1;
-    scale -= 1;
-  }
-  Serial.println(fibo);
-  Serial.println(scale);
-  Serial.println(fibo << scale);
+  fibi++;
+  if( fibi == 128 ) {
+    fibi = 0;
   }
+  Serial.println("Setting wave");
   
+  setwave();
+  phase = 0;
+}
 
 
 void loop() {
-  int p0 = phase - 1;
-  int p1 = phase + 2;
-  if( p0 < 0 ) {
-    p0 += nsamp;
-  }
-  if( p1 < 0 ) {
-    p1 += nsamp;
-  }
-  waveform[phase] = (waveform[p1] + waveform[p0]) % fibo;
-  mcp.fastWrite(waveform[phase] << scale, 0, 0, 0);
+  mcp.fastWrite(waveform[phase] << 4, 0, 0, 0);
   phase += 1;
-  if( phase >= nsamp ) {
+  if( phase == pmax ) {
     phase = 0;
   }
 }