#include <Servo.h>

Servo myservo;  

int pos = 0;    

void setup() {
  myservo.attach(9);  
  Serial.begin(9600);
}

void loop() {
  for (pos = 0; pos <= 180; pos += 1) { 
    myservo.write(pos);              
    delay(150);                       
    float distancia = sonar(7,8);
    Serial.println(distancia);
  }
  for (pos = 180; pos >= 0; pos -= 1) { 
    myservo.write(pos);              
    delay(150);                       
    float distancia = sonar(7,8);
    Serial.println(distancia);
  }
}

float sonar(int pino_TRIG, int pino_ECO) {
  float tempo, distancia;
  pinMode(pino_TRIG, OUTPUT) ;
  pinMode(pino_TRIG, INPUT) ;
  digitalWrite(pino_TRIG, LOW) ;
  delayMicroseconds(2);
  digitalWrite(pino_TRIG, HIGH) ;
  delayMicroseconds(10);
  digitalWrite(pino_TRIG, LOW) ;
  tempo = pulseIn(pino_ECO, HIGH);
  distancia = (tempo * 0.0343) / 2;
  return distancia;
}