Blynk_example_v4

#define BLYNK_PRINT Serial
#include <WiFi.h>
#include <WiFiClient.h>
#include <BlynkSimpleEsp32.h>
#include <Wire.h>
#include <LiquidCrystal_I2C.h>
BlynkTimer timer;
LiquidCrystal_I2C lcd(0x27, 20, 4);
char auth[] = "xxx";
char ssid[] = "xxx";
char pass[] = "xxx";
int measurePin = 4;
int ledPower = 2;
int samplingTime = 280;
int deltaTime = 40;
int sleepTime = 9680;
float voMeasured = 0;
float calcVoltage = 0;
float dustDensity = 0;

void myTimerEvent(){            //Put your loop instruction in here with the Virtual pins at the end
    digitalWrite(ledPower,LOW);
    delayMicroseconds(samplingTime);
    voMeasured = analogRead(measurePin);
    delayMicroseconds(deltaTime);
    digitalWrite(ledPower,HIGH);
    delayMicroseconds(sleepTime);
    calcVoltage = voMeasured * (5.0 / 1024.0);
    dustDensity = 0.17 * calcVoltage - 0.1;
    Blynk.virtualWrite(V20,voMeasured );
    Blynk.virtualWrite(V21, calcVoltage);
    Blynk.virtualWrite(V22, dustDensity);
    updateLCD(voMeasured, calcVoltage, dustDensity);
}

void updateLCD(float newVO, float newVolts, float newDust){
    lcd.setCursor(1,1);
    lcd.print(newVO, 2);
    lcd.setCursor(9,2);
    lcd.print(newVolts, 2);
    lcd.setCursor(14,3);
    lcd.print(newDust, 2);

    return;
}
void setup(){
    Blynk.begin(auth, ssid, pass);
    lcd.begin();
    lcd.backlight();
    lcd.setCursor(0,0);
    lcd.print("Raw Signal Value: ");
    lcd.setCursor(0,2);
    lcd.print("Voltage:");
    lcd.setCursor(0,3);
    lcd.print("Dust Density:");
    pinMode(ledPower,OUTPUT);
    timer.setInterval(1000L, myTimerEvent);   //This sets the time between samples
}
void loop(){
  Blynk.run();
  timer.run();
}