//Find the fastest blink that the human eye can still detect
const int ledPin = 2; //Pin connected to the LED
const int blinkInterval = 1; //Delay in milliseconds

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

void loop() {
  digitalWrite(2, HIGH); //Turn on the LED
  delay(3);
  digitalWrite(2, LOW); //Turn off the LED
  delay(3);
}