/*
  HC-SR04 Ultrasonic Sensor Example.

  Turn the LED on when an object is within 100cm range.

  Copyright (C) 2021, Uri Shaked
*/

#define ECHO_PIN 2
#define TRIG_PIN 3
int ledRojo = 13;
int ledAmarillo = 11;
int ledVerde = 12;

void setup() {
  Serial.begin(115200);
  pinMode(ledRojo, OUTPUT);
  pinMode(ledAmarillo, OUTPUT);
  pinMode(ledVerde, OUTPUT);
  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);
}

float readDistanceCM() {
  digitalWrite(TRIG_PIN, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);
  int duration = pulseIn(ECHO_PIN, HIGH);
  return duration * 0.034 / 2;
}

void loop() {
  float distance = readDistanceCM();

  bool muyCerca = distance < 100;
  bool cerca = distance > 100 && distance < 200;
  bool lejos = distance > 200 && distance < 300;

  if (muyCerca) {
    digitalWrite(ledRojo, HIGH);
    digitalWrite(ledAmarillo, LOW);
    digitalWrite(ledVerde, LOW);
  } else if (cerca) {
    digitalWrite(ledRojo, LOW);
    digitalWrite(ledAmarillo, HIGH);
    digitalWrite(ledVerde, LOW);
  } else if (lejos) {
    digitalWrite(ledRojo, LOW);
    digitalWrite(ledAmarillo, LOW);
    digitalWrite(ledVerde, HIGH);
  }

  Serial.print("Measured distance: ");
  Serial.println(readDistanceCM());

  delay(100);
}