// Forum: https://forum.arduino.cc/t/random-function-not-randomising-after-reset/1161545
// Sketch by: maagdappel
// Changes by: Koepel, 24 August 2023.

const int led_green = 4;
const int led_yellow = 5;
const int led_red = 3;
const int buzzer = 9;

void setup() 
{
  Serial.begin(9600);
  Serial.println("--------------------------------------");
  
  pinMode(led_green, OUTPUT);
  pinMode(led_yellow, OUTPUT);
  pinMode(led_red, OUTPUT);
  pinMode(buzzer, OUTPUT);

  // The values of analogRead are added, that is not ideal.
  // They could be multiplied or with XOR or something else.
  // Every "expert" about random tells something different. 
  unsigned long seed = 0;
  for(int i = A0; i <= A5; i++)
  {
    seed += analogRead(i); 
  }
  randomSeed(seed);
}

void loop() 
{
  int chance = random(3);

  int data = analogRead(A0);
  float voltage = data * (5.00 / 1023.00);
  int percentage = map(data, 0, 1023, 0, 100);

  Serial.print("Potentiometer at ");
  Serial.print(voltage);
  Serial.print("V or ");
  Serial.print(percentage);
  Serial.print("%. ");
  Serial.print("The random number is: ");
  Serial.print(chance);
  Serial.println();

  int brightness = map(data, 0, 1023, 0, 255);
  int sound = map(data, 0, 1023, 0, 255);

  switch(chance)
  {
    case 0:
      analogWrite(led_green, brightness);
      noTone(buzzer);
      break;
    case 1:
      analogWrite(led_yellow, brightness);
      noTone(buzzer);
      break;
    case 2:
      analogWrite(led_red, brightness);
      tone(buzzer, sound);
      break;
  }

  delay(500);      // slow down the sketch
}