frequency blink

gistfile1.c

void blink(int frequency) {
  int milliseconds = 1000/frequency;

  digitalWrite(ledPin, HIGH);
  delay(milliseconds);
  digitalWrite(ledPin, LOW);
  delay(milliseconds);
}

void loop() {
  for (int i=4; i <= 8; i++) {
    blink(i);
  }
}