Sumer_Is_Icummen_In_5.ino

/*
  Summer is Icummen In - Part 5
  By Chris Chungbin
  Plays the first accompanying part of a piece of 13th-century polyphony
  **Also acts as the time synchronization controller**
  Sends a pulse just before the beginning of each "t" period
*/

unsigned long temp=360;  //set note rate in bpm of the GCF of note duration
unsigned int t=0;  //time var in periods of the variable "temp"

float pitch[]=        {349.23, 392.00, 349.32, 392.00, 466.16, 523.25, 466.16, 523.25, 000.00,
                       349.23, 392.00, 349.32, 392.00, 466.16, 523.25, 466.16, 523.25, 000.00,
                       349.23, 392.00, 349.32, 392.00, 466.16, 523.25, 466.16, 523.25, 000.00,
                       349.23, 392.00, 349.32, 392.00, 466.16, 523.25, 466.16, 523.25, 000.00,
                       349.23, 392.00, 349.32, 392.00, 466.16, 523.25, 466.16, 523.25, 000.00,
                       349.23, 392.00, 349.32, 392.00, 466.16, 523.25, 466.16, 523.25, 000.00,
                       349.23, 392.00, 349.32, 392.00, 466.16, 523.25, 466.16, 523.25, 000.00,
                       349.23, 392.00, 349.32, 392.00, 466.16, 523.25, 466.16, 523.25, 000.00,
                       349.23, 392.00, 349.32, 392.00, 466.16, 523.25, 466.16, 523.25, 000.00 };  //frequency of each note in Hz
unsigned int time[]=  {3,      3,      3,      2,      1,      3,      3,      3,      3,
                       3,      3,      3,      2,      1,      3,      3,      3,      3,
                       3,      3,      3,      2,      1,      3,      3,      3,      3,
                       3,      3,      3,      2,      1,      3,      3,      3,      3,
                       3,      3,      3,      2,      1,      3,      3,      3,      3,
                       3,      3,      3,      2,      1,      3,      3,      3,      3,
                       3,      3,      3,      2,      1,      3,      3,      3,      3,
                       3,      3,      3,      2,      1,      3,      3,      3,      3,
                       3,      3,      3,      2,      1,      3,      3,      3,      6, 1, 1};  //duration of note in time rate periods - multiple of shortest note value - add 2 other elements after the last duration to allow index shifting later

void setup() {
  pinMode(8, OUTPUT);  //audio out
  pinMode(7, OUTPUT);  //sync pulse out to other boards
  pinMode(13, INPUT);  //part 1 reply - connected to other boards' ready signal
  pinMode(12, INPUT);  //part 2 reply
  pinMode(11, INPUT);  //part 3 reply
  pinMode(10, INPUT);  //part 4 reply
  pinMode(9, INPUT);  //part 6 reply
  digitalWrite(7,LOW);

  temp=60000000/temp;  //convert bpm tempo to period in microseconds

  for(int i=0; i<sizeof(pitch)/4; i++) {
    pitch[i]=pitch[i]/2;
  }

  for(int i=sizeof(time)/2-1; i>0; i--) {  //this and the next for() convert time[] to start time of note
    time[i]=time[i-1];
  }
  time[0]=0;
  for(int i=1; i<sizeof(time)/2-1; i++) {
   time[i]=time[i-1]+time[i];
  }


  delay(1000);  //extra long wait for other boards to be ready. allows inaccuracy in resetting

  while(!(digitalRead(9)&&digitalRead(10)&&digitalRead(11)&&digitalRead(12)&&digitalRead(13))) {
    //do nothing until all boards report HIGH
  }

  digitalWrite(7, HIGH);  //tell the other boards to turn off their ready signal and wait for start
  delay(1);
  digitalWrite(7, LOW);
  delay(1);

}

void loop() {
  t=0;
  unsigned long s=micros();  //period start time
  unsigned long p=0;  //period
  unsigned long tTime=micros();  //time of last t-sync pulse start
  unsigned int start=micros();  //start time recorded

  for (int i=0; i<sizeof(pitch)/4; i++) {
    while(time[i+1]>t) {
      s=micros();
      if(micros()-tTime>temp) {  //t update and sync pulse
        t=t+1;
        digitalWrite(7, HIGH);
        tTime=micros();
      }
      if(micros()-tTime>temp/2) {
        digitalWrite(7, LOW);
      }
      if(pitch[i]==0) {
      }
      else {
        p=1000000/pitch[i];
        digitalWrite(8, HIGH);
        delayMicroseconds(p/3);
        digitalWrite(8, LOW);
        while(micros()-s<p) {
          //waits in this incredibly exciting loop until the current period is done
        }
      }
    }
  }
  digitalWrite(7,LOW);
  while(1) {
  }
}