/*
  HC-SR04 Ultrasonic Sensor Example.

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

  Copyright (C) 2021, Uri Shaked
*/

#define ECHO1_PIN 2
#define TRIG1_PIN 3
#define ECHO2_PIN 6
#define TRIG2_PIN 7

void setup() {
  Serial.begin(115200);
  pinMode(13, OUTPUT);
  pinMode(12, OUTPUT);
  pinMode(TRIG1_PIN, OUTPUT);
  pinMode(ECHO1_PIN, INPUT);
  pinMode(TRIG2_PIN, OUTPUT);
  pinMode(ECHO2_PIN, INPUT);
}

float readDistanceCM1() {
  digitalWrite(TRIG1_PIN, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIG1_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG1_PIN, LOW);
  
  int duration1 = pulseIn(ECHO1_PIN, HIGH);

  return duration1 * 0.034 / 2;
}

float readDistanceCM2() {
  digitalWrite(TRIG2_PIN, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIG2_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG2_PIN, LOW);
  
  int duration2 = pulseIn(ECHO2_PIN, HIGH);

  return duration2 * 0.034 / 2;
}


void loop() {
  float distance1 = readDistanceCM1();

  bool isNearby1 = distance1 < 100;
  digitalWrite(LED_BUILTIN, isNearby1);

  Serial.print("Measured distance 1: ");
  Serial.print(readDistanceCM1());
  Serial.print("  | ");


  float distance2 = readDistanceCM2();

  bool isNearby2 = distance2 < 100;
  digitalWrite(12, isNearby2);

  Serial.print("Measured distance 2: ");
  Serial.println(readDistanceCM2());

  delay(100);
}