---

#include <QuadDisplay.h>

#define DISPLAY_PIN 3
#define trigPin 9
#define echoPin 10

long duration;
float distance_cm;
int distance_int;

void setup() {
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
  
  displayClear(DISPLAY_PIN);
  displayInt(DISPLAY_PIN, 0);
}

void loop() {
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
  
  duration = pulseIn(echoPin, HIGH);
  distance_cm = duration * 0.034 / 2;
  
  if (distance_cm < 0) distance_int = 0;
  else if (distance_cm > 9999) distance_int = 9999;
  else distance_int = (int)distance_cm;
  
  displayInt(DISPLAY_PIN, distance_int);
  
  delay(300);
}