//#include <Wire.h>

#include <LiquidCrystal_I2C.h>

int lcdColumns=16;
int lcdRows=2;
const int trigPin = 5;
const int echoPin = 18;
#define SOUND_SPEED 0.034
#define CM_TO_INCH 0.393701

long duration;
float distanceCm=1;
float distanceInch=1;
LiquidCrystal_I2C lcd(0x27, lcdColumns, lcdRows);

void setup() {
  lcd.init();
  // turn on LCD backlight                      
  lcd.backlight();

  //Wire.begin();
  //Serial.println("\nI2C Scanner");
  // put your setup code here, to run once:
  //Serial.begin(115200);
  Serial.println("Hello, ESP32!");
  pinMode(26, OUTPUT);
  // pinMode(trigPin, OUTPUT); // Sets the trigPin as an Output
  //pinMode(echoPin, INPUT);
}

void loop() {
  lcd.setCursor(0, 0);
  // print message
  lcd.print("Hello, World!");
  delay(1000);
  // clears the display to print new message
  lcd.clear();
  // set cursor to first column, second row
  lcd.setCursor(0,1);
  lcd.print("Hello, World!");
  delay(1000);
  lcd.clear();
 // byte error, address;
  // int nDevices;
  // Serial.println("Scanning...");
  // nDevices = 0;
  // for(address = 1; address < 127; address++ ) {
  //   Wire.beginTransmission(address);
  //   error = Wire.endTransmission();
  //   if (error == 0) {
  //     Serial.print("I2C device found at address 0x");
  //     if (address<16) {
  //       Serial.print("0");
  //     }
  //     Serial.println(address,HEX);
  //     nDevices++;
  //   }
  //   else if (error==4) {
  //     Serial.print("Unknow error at address 0x");
  //     if (address<16) {
  //       Serial.print("0");
  //     }
  //     Serial.println(address,HEX);
  //   }    
  // }
  // if (nDevices == 0) {
  //   Serial.println("No I2C devices found\n");
  // }
  // else {
  //   Serial.println("done\n");
  // }
  // delay(5000);          
   digitalWrite(26, HIGH);
  // // put your main code here, to run repeatedly:
   delay(1000);
   digitalWrite(26, LOW);
   delay(1000); // this speeds up the simulation
   digitalWrite(trigPin, LOW);
   delayMicroseconds(2);
  //Sets the trigPin on HIGH state for 10 micro seconds
   digitalWrite(trigPin, HIGH);
   delayMicroseconds(10);
   digitalWrite(trigPin, LOW);
  
  // // Reads the echoPin, returns the sound wave travel time in microseconds
  // duration = pulseIn(echoPin, HIGH);
  
  // // Calculate the distance
  // distanceCm = duration * SOUND_SPEED/2;
  
  // // Convert to inches
  // distanceInch = distanceCm * CM_TO_INCH;
  
  // // Prints the distance in the Serial Monitor
  // Serial.print("Distance (cm): ");
  // Serial.println(distanceCm);
  // Serial.print("Distance (inch): ");
  // Serial.println(distanceInch);
  
  // delay(1000);
}