int potPin = A0;     // Potentiometer connected to A0
int buzzerPin = PA5; // Buzzer connected to PA5

int threshold = 2000;

void setup() {
  pinMode(buzzerPin, OUTPUT);
  Serial.begin(115200);
}

void loop() {

  int value = analogRead(potPin); // Read potentiometer

  Serial.print("Signal Value: ");
  Serial.println(value);

  if(value < threshold) {
    digitalWrite(buzzerPin, HIGH); // Child far
    Serial.println("Child is FAR");
  }
  else {
    digitalWrite(buzzerPin, LOW); // Child near
    Serial.println("Child is SAFE");
  }

  delay(300);
}