Stripped-back fibomod

Fibomod2/Fibomod2.ino

@@ -0,0 +1,63 @@
+// can fibomod make an interesting noise?
+
+
+#include <Adafruit_MCP4728.h>
+#include <Wire.h>
+
+Adafruit_MCP4728 mcp;
+
+
+unsigned int fibo = 43;
+unsigned int a = 0;
+unsigned int b = 1;
+
+void setup() {
+
+  cli();
+
+//set timer1 interrupt at 1Hz
+  TCCR1A = 0;// set entire TCCR1A register to 0
+  TCCR1B = 0;// same for TCCR1B
+  TCNT1  = 0;//initialize counter value to 0
+  // 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 = 1000;
+  // turn on CTC mode
+  TCCR1B |= (1 << WGM12);
+  // Set CS10 and CS12 bits for 1024 prescaler
+  TCCR1B |= (1 << CS12) | (1 << CS10);  
+  // enable timer compare interrupt
+  TIMSK1 |= (1 << OCIE1A);
+
+  sei();
+
+
+
+  Serial.begin(115200);
+
+  if (!mcp.begin(0x64)) {
+    while (1) {
+      delay(100);
+    }
+  }
+
+  mcp.setSpeed(800000L);
+
+}
+
+
+ISR(TIMER1_COMPA_vect){
+  fibo = analogRead(A0);
+  if( fibo < 3 )
+  Serial.println(fibo);
+}
+
+
+void loop() {
+  unsigned int c = (a + b) % fibo;
+  a = b;
+  b = c;
+  mcp.fastWrite(a << 2, 0, 0, 0);
+}
+