01_random_blinky.ino

/* Activity 01 - Random Blinky

  Blinks LED chaotically based on a random number.
  Uses onboard LED connected to pin 13.
*/

#define LED_PIN 13  // define LED pin

// put your setup code here, to run once:
void setup() {
  // if analog input pin 0 is unconnected, random analog
  // noise will cause the call to randomSeed() to generate
  // different seed numbers each time the sketch runs.
  // randomSeed() will then shuffle the random function.
  randomSeed(analogRead(0));
  // initialize digital pin 13 (LED) as an output
  pinMode(LED_PIN, OUTPUT);
  pinMode(2, OUTPUT);
}

// put your main code here, to run repeatedly:
void loop() {
  // choose random number between 0 and 2, not including 2
  int rand_num = random(0,2);
  
  digitalWrite(LED_PIN, rand_num);  // turn the LED on
  digitalWrite(2, rand_num);
  delay(500);
}