void setup()  { 
  pinMode(0,OUTPUT);
  pinMode(2,OUTPUT);
} 


void loop ()
{
  digitalWrite(0,LOW);						// no output for 10s
  digitalWrite(2,LOW);
  delay(10000);
  
  for (int i=0; i<250; i++){				// 12.5 Hz for 20s
    digitalWrite(0,LOW);
    digitalWrite(2,HIGH);
    delay(40);
    digitalWrite(0,HIGH);
    digitalWrite(2,LOW);
    delay(40);
	}
  
  digitalWrite(0,LOW);						// no output for 10s
  digitalWrite(2,LOW);
  delay(10000);
  
  for (int i=0; i<10000; i++){				// 500 Hz for 20s
    digitalWrite(0,LOW);
    digitalWrite(2,HIGH);
    delay(1);
    digitalWrite(0,HIGH);
    digitalWrite(2,LOW);
    delay(1);
  }
  
  digitalWrite(0,LOW);						// no output for 10s
  digitalWrite(2,LOW);
  delay(10000);
  
  for (int i=0; i<100000; i++){				// 5000 Hz for 20s
    digitalWrite(0,LOW);
    digitalWrite(2,HIGH);
    delayMicroseconds(100);
    digitalWrite(0,HIGH);
    digitalWrite(2,LOW);
    delayMicroseconds(100);
  }
}