//Muhammad Alfarizqi
//211910201014

#define BLYNK_TEMPLATE_ID "TMPL6B6jkbovX"
#define BLYNK_TEMPLATE_NAME "Parking System"
#define BLYNK_AUTH_TOKEN "K34o9OnQiyLH-iIJIPSIN-fVPWC4dLk_"

//Including Library files
#define BLYNK_PRINT Serial
#include <WiFi.h>
#include <WiFiClient.h>
#include <BlynkSimpleEsp32.h>

//Defining wifi credentials
char auth[] = BLYNK_AUTH_TOKEN;
char ssid[] = "Wokwi-GUEST";
char pass[] = "";

//Defining Pin numbers 
#define ECHO_A 2
#define TRIG_A 18
#define ECHO_B 4
#define TRIG_B 5
#define ECHO_C 13
#define TRIG_C 14
#define ECHO_D 17
#define TRIG_D 16
#define buzzer 19

int a,b,c,d;
int Slot;

//char full[] = "Full";
//char fr[] = "Free";

BlynkTimer timer;

void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);

  Blynk.begin(BLYNK_AUTH_TOKEN, ssid, pass);
//Defining Pin modes
  pinMode(TRIG_A, OUTPUT);
  pinMode(ECHO_A, INPUT);
  pinMode(TRIG_B, OUTPUT);
  pinMode(ECHO_B, INPUT);
  pinMode(TRIG_C, OUTPUT);
  pinMode(ECHO_C, INPUT);
  pinMode(TRIG_D, OUTPUT);
  pinMode(ECHO_D, INPUT);
  pinMode(buzzer, OUTPUT);

  Serial.begin(115200);
  Serial.println("Hello, ESP32!");
}

void loop() {
  // put your main code here, to run repeatedly:
  a=check(TRIG_A,ECHO_A);
  tone(buzzer, 1000);
  noTone(buzzer);
  if(a==0){
     Blynk.virtualWrite(V1, 0 );
     tone(buzzer, 1000);
     //delay(100);
     //noTone(buzzer);
  }
  else{
     Blynk.virtualWrite(V1, 1);
     noTone(buzzer);
  }
  b=check(TRIG_B,ECHO_B);
  if(b==0){
     Blynk.virtualWrite(V2, 0 );
     tone(buzzer, 1000);
     //delay(100);
  }
  else{
     Blynk.virtualWrite(V2, 1);
     noTone(buzzer);
  }
  c=check(TRIG_C,ECHO_C);
  if(c==0){
     Blynk.virtualWrite(V3, 0 );
     tone(buzzer, 1000);
     //delay(100);
  }
  else{
     Blynk.virtualWrite(V3, 1);
     noTone(buzzer);
  }
  d=check(TRIG_D,ECHO_D);
  if(d==0){
     Blynk.virtualWrite(V4, 0 );
     tone(buzzer, 1000);
     //delay(100);
  }
  else{
     Blynk.virtualWrite(V4, 1);
     noTone(buzzer);
  }
  Serial.printf("%d %d %d %d \n",a,b,c,d);
  Slot=a+b+c+d;
  Serial.printf("slots free = %d \n",Slot);
  Blynk.virtualWrite(V0, Slot);
  delay(2000); // this speeds up the simulation
}

//function to chech distance
float check(int trigerpin, int echopin){
    float distance, duration;
    digitalWrite(trigerpin, LOW);
    delay(2);
    digitalWrite(trigerpin, HIGH);
    delay(10);
    digitalWrite(trigerpin, LOW);
    duration=pulseIn(echopin,HIGH);
    distance=duration/2*0.034;
    Serial.print("distance (in cm)=");
    Serial.println(distance);
    delay(10);
    if(distance>100){
      return 1;

    } 
    else{
      return 0;
    }
 }