int analogPin = A0; // potentiometer wiper (middle terminal) connected to analog pin 3
                    // outside leads to ground and +5V
float val = 0;  // variable to store the value read
float distancia;
float tensao;
float incerteza;
float timestamp = 0;

void setup() {
  // put your setup code here, to run once:
  Serial.begin(9600);           //  setup serial
  Serial.println("timestamp, medida, incerteza");
}

void loop() {
  // put your main code here, to run repeatedly:
    val = analogRead(analogPin);  // read the input pin
    val = map(val, 0, 1023, 314, 891);     // scale it to use it with the servo (value between 0 and 180)
    //Serial.println(val);
    tensao = val*5/1024;
    //Serial.println(tensao);
    distancia = -1.4968*tensao*tensao + 12.874*tensao - 15.835;
    incerteza = distancia * 0.05;
    Serial.print(timestamp);          // debug value
    Serial.print(",");
    Serial.print(distancia);
    Serial.print(",");
    Serial.println(incerteza);
    timestamp = timestamp + 0.2;
    delay(200); // faz 5 vezes por segundo
}