---

#define PR A0
#define LED_B 3
#define LED_R 5

void setup() {
  Serial.begin(9600);

  pinMode(PR, INPUT);
  pinMode(LED_B, OUTPUT);
  pinMode(LED_R, OUTPUT);
}

void loop() {
  int prValue = analogRead(PR);

  int newValue = map(prValue, 0, 1023, 0, 20000);

  Serial.print("Value = ");
  Serial.println(newValue);
  
  if (newValue >= 3000) {
    digitalWrite(LED_B, HIGH);
  } else {
    digitalWrite(LED_B, LOW);
  }

  analogWrite(LED_R, map(newValue, 0, 20000, 255, 0));
}