// https://forum.arduino.cc/t/random-led-time-on-off-using-millis/979561

unsigned long currentTime = millis();

const int crow1eyes = 2;   // pin for crow 1 eyes
unsigned long crow1On;   // OFF time for crow 1 eyes
unsigned long crow1Off;   // ON time for crow 1 eyes
int crow1State = HIGH;   // starting state of crow 1 eyes
unsigned long PrevEyesTime1;   // time used by code to keep track of crow 1 time

// changed these for testing, life too short!
const int eyesOnMinimum = 100;
const int eyesOnMaximum = 500;
const int eyesOffMinimum = 100;
const int eyesOffMaximum = 200;

const int crow2eyes = 3;   // pin for crow 2 eyes
unsigned long crow2On;   // OFF time for crow 2 eyes
unsigned long crow2Off;   // ON time for crow 2 eyes
int crow2State = HIGH;   // starting state of crow 2 eyes
unsigned long PrevEyesTime2;   //time used by code to keep track of crow 1 time


void setup() {
  Serial.begin(112500);
  Serial.println("random eyes!\n");

  pinMode(crow1eyes, OUTPUT); //sets eyes pin as output
  digitalWrite(crow1eyes, crow1State);  //sets initial state
  pinMode(crow2eyes, OUTPUT);  //define eyes pin as output
  digitalWrite(crow2eyes, crow2State);  //sets initial state

// for testing
  crow1On = 1000; crow1Off = 200;
  crow2On = 1333; crow2Off = 333;
  
}

void loop() {
  currentTime = millis();

/* NOT every time you loop!
  crow1On = random(eyesOnMinimum, eyesOnMaximum);
  crow1Off = random(eyesOffMinimum, eyesOffMaximum);
  crow2On = random(eyesOnMinimum, eyesOnMaximum);
  crow2Off = random(eyesOffMinimum, eyesOffMaximum);
*/

  if (crow1State == HIGH) {
    if (currentTime - PrevEyesTime1 >= crow1On) {
      crow1State = LOW;

// just every time you actually use a random value, get a new one for next time
      crow1On = random(eyesOnMinimum, eyesOnMaximum);

      PrevEyesTime1 = currentTime;
    }

  }
  else {
    if (currentTime - PrevEyesTime1 >= crow1Off) {
      crow1State = HIGH;

      crow1Off = random(eyesOffMinimum, eyesOffMaximum);

      PrevEyesTime1 = currentTime;
    }
  }
  digitalWrite(crow1eyes, crow1State);

  if (crow2State == HIGH ) {
    if (currentTime - PrevEyesTime2 >= crow2On) {
      crow2State = LOW;
      PrevEyesTime2 = currentTime;
    }
  }
  else {
    if (currentTime - PrevEyesTime2 >= crow2Off) {
      crow2State = HIGH;
      PrevEyesTime2 = currentTime;
    }
  }
  digitalWrite(crow2eyes, crow2State);
}