/**
   ESP32 + DHT22 Example for Wokwi
   
   https://wokwi.com/arduino/projects/322410731508073042
*/

/*********
  Rui Santos
  Complete project details at https://RandomNerdTutorials.com/esp32-hc-sr04-ultrasonic-arduino/
  
  Permission is hereby granted, free of charge, to any person obtaining a copy
  of this software and associated documentation files.
  
  The above copyright notice and this permission notice shall be included in all
  copies or substantial portions of the Software.
*********/

#include <ESP32Servo.h>

Servo myservo;  // create servo object to control a servo

int pos = 0;    // variable to store the servo position

// First HC-SR04 Sensor Pins
const int trigPin = 12;
const int echoPin = 27;

// Second HC-SR04 Sensor Pins
const int trigPin2 = 25;
const int echoPin2 = 33;

// Relay Pin
const int relayPin = 26;

// Define sound speed in cm/uS
#define SOUND_SPEED 0.034
#define CM_TO_INCH 0.393701

long duration, duration2;
float distanceCm, distanceCm2;
float distanceInch, distanceInch2;

void setup() {
  Serial.begin(115200); // Starts the serial communication
  pinMode(trigPin, OUTPUT); // Sets the trigPin as an Output
  pinMode(echoPin, INPUT); // Sets the echoPin as an Input
  pinMode(trigPin2, OUTPUT); // Sets the trigPin2 as an Output
  pinMode(echoPin2, INPUT); // Sets the echoPin2 as an Input
  pinMode(relayPin, OUTPUT); // Sets the relayPin as an Output
  myservo.attach(13);  // attaches the servo on pin 13 to the servo object
}

void loop() {
  // First HC-SR04 Sensor
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
  duration = pulseIn(echoPin, HIGH);
  distanceCm = duration * SOUND_SPEED/2;
  distanceInch = distanceCm * CM_TO_INCH;
  Serial.print("Distance 1 (cm): ");
  Serial.println(distanceCm);

  // Second HC-SR04 Sensor
  digitalWrite(trigPin2, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin2, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin2, LOW);
  duration2 = pulseIn(echoPin2, HIGH);
  distanceCm2 = duration2 * SOUND_SPEED/2;
  distanceInch2 = distanceCm2 * CM_TO_INCH;
  Serial.print("Distance 2 (cm): ");
  Serial.println(distanceCm2);

  // Control Servo
  if(distanceCm < 50) {
    myservo.write(180);
    delay(15);
  } else {
    myservo.write(90);
    delay(15);
  }

  // Control Relay
  if(distanceCm2 > 50) {
    digitalWrite(relayPin, HIGH); // Turn on relay if distance is more than 50 cm
  } else {
    digitalWrite(relayPin, LOW); // Turn off relay otherwise
  }

  delay(1000);
}