#define BLYNK_TEMPLATE_ID "TMPL3k-B39Oiw"
#define BLYNK_TEMPLATE_NAME "AC Voltmeter"
#define BLYNK_AUTH_TOKEN "4vGeHNxEpeF4hSwvmrMZBwKwVo02T2XM"


#define BLYNK_PRINT Serial
 
 #include "EmonLib.h"
 #include <WiFi.h>
 #include <WiFiClient.h>
 #include <BlynkSimpleEsp32.h>
 #include <Wire.h>
 #include <LiquidCrystal_I2C.h>
 LiquidCrystal_I2C lcd(0x27, 20, 4);
  
  // Constants for calibration
  const float vCalibration = 175;

  // Blynk and WiFi credentials

  char auth[] = BLYNK_AUTH_TOKEN; // Blynk authentication token
  const char* ssid = "Galaxy F23 5G 3FF5"; // Your WiFi network SSID
  const char* pass = "edrp6836ehan"; // Your WiFi network password
   
   // EnergyMonitor instance
   EnergyMonitor emon;
    
    // Timer for regular updates
    BlynkTimer timer; 

    unsigned long lastMillis = millis();
      
      void setup()
      {
        Serial.begin(115200);
          Blynk.begin(auth, ssid, pass);
           
             // Initialize the LCD
                lcd.begin();    
                 // Display "Tech Trends Shameer"
                   lcd.setCursor(3, 0);
                     lcd.print("Tech Trends ");
                       lcd.setCursor(3, 1);
                         lcd.print("  Shameer    ");
                           delay(3000);  // Wait for 3 seconds

                               // Clear the LCD and display "AC Voltmeter"
                                 lcd.clear();
                                   lcd.setCursor(3, 0);
                                     lcd.print("AC Voltmeter"); 
                                       delay(2000);
                                        
                                          // Setup voltage and current inputs
                                            emon.voltage(35, vCalibration, 1.7); // Voltage: input pin, calibration, phase_shift  
                                             
                                               // A small delay for system to stabilize
                                                 delay(1000);
                                                 }
                                                  
                                                   
                                                   void loop()
                                                   {
                                                     emon.calcVI(25, 1000);       // Calculate all. No. of half wavelengths (crossings), time-out
                                                       
                                                         float supplyVoltage = emon.Vrms;  // Extract Vrms into a variable
                                                           
                                                             lcd.clear();  // Clear the LCD display
                                                               
                                                                 if (supplyVoltage >= 100)
                                                                   {
                                                                       lcd.setCursor(0, 0);
                                                                           lcd.print("Voltage: ");
                                                                               lcd.print(supplyVoltage);
                                                                                   lcd.print(" V");
                                                                                       Serial.print("Voltage : ");
                                                                                           Serial.println(supplyVoltage);
                                                                                               Blynk.virtualWrite(V1, supplyVoltage); // Send voltage value to Blynk virtual pin V1
                                                                                                 }
                                                                                                   else
                                                                                                     {
                                                                                                         lcd.setCursor(0, 0);
                                                                                                             lcd.print("Power OFF");
                                                                                                                 Serial.println("Power OFF");
                                                                                                                     Blynk.virtualWrite(V1, supplyVoltage);
                                                                                                                       }

                                                                                                                         delay(1000);  // Delay before taking the next reading
                                                                                                                           Blynk.run(); // Run Blynk
                                                                                                                           }