#define BLYNK_PRINT Serial

#define BLYNK_TEMPLATE_ID "TMPL5WaC2CdoZ"
#define BLYNK_TEMPLATE_NAME "Ultrasonic Distance Sensor Testing with 2 LED"
#define BLYNK_AUTH_TOKEN "-shpZOflUM5aqrudWKDdVREvVzsdSaMm"

#include <WiFi.h>
#include <WiFiClient.h>
#include <BlynkSimpleEsp32.h>

char ssid[] = "Wokwi-GUEST";
char pass[] = "";

#define t 26     // Trigger pin
#define e 25      // Echo pin
#define greenLED 17 // Green LED pin
#define redLED 16   // Red LED pin

long echo;
float distance;

void setup() {
  Serial.begin(9600);
  pinMode(t, OUTPUT);
  pinMode(e, INPUT); 
  pinMode(greenLED, OUTPUT);
  pinMode(redLED, OUTPUT);
  Blynk.begin(BLYNK_AUTH_TOKEN, ssid, pass);
}

void loop() {
  Blynk.run();
  readSensor();
}

long pre = 0;
void readSensor(){
  if(millis() - pre > 2000){
    pre = millis();
    digitalWrite(t, LOW);
    delay(10);
    digitalWrite(t, HIGH);
    delayMicroseconds(10);  
    digitalWrite(t, LOW);
    echo = pulseIn(e, HIGH);
    distance = (echo / 2.0) / 29.0;
    
    Blynk.virtualWrite(V5, distance); // Send distance to Blynk app
    
    if(distance < 100){
      Blynk.virtualWrite(V1, HIGH); // Turn on green LED widget
      Blynk.virtualWrite(V2, LOW); // Turn off red LED widget
      digitalWrite(greenLED, HIGH);
      digitalWrite(redLED, LOW);
    } else {
      Blynk.virtualWrite(V1, LOW); // Turn off green LED widget
      Blynk.virtualWrite(V2, HIGH); // Turn on red LED widget
      digitalWrite(greenLED, LOW);
      digitalWrite(redLED, HIGH);
    }
    
    Serial.println(distance);
  }
}

// Blynk virtual pin write handlers
BLYNK_WRITE(V1) {
  int pinValue = param.asInt();
  digitalWrite(greenLED, pinValue);
}

BLYNK_WRITE(V2) {
  int pinValue = param.asInt();
  digitalWrite(redLED, pinValue);
}