#include <LiquidCrystal.h>
#include <Wire.h>

LiquidCrystal lcd(2, 3, 4, 5, 6, 7);
int BH1750address = 0x23;
byte buff[2];

void setup() {
  Wire.begin();
  lcd.begin(16, 2);
  lcd.print("  BH1750 Light  ");
  lcd.setCursor(0, 1);
  lcd.print("Intensity Sensor");
  delay(2000);
  lcd.clear();
}

void loop() {
  int i;
  uint16_t value = 0;
  BH1750_Init(BH1750address);
  delay(200);

  if (2 == BH1750_Read(BH1750address)) {
    value = ((buff[0] << 8) | buff[1]) / 1.2;
    lcd.setCursor(0, 0);
    lcd.print("Intensity in LUX");
    lcd.setCursor(6, 1);
    lcd.print(value);
    lcd.print("   ");
  }
  delay(150);
}

int BH1750_Read(int address) {
  int i = 0;
  Wire.beginTransmission(address);
  Wire.requestFrom(address, 2);
  while (Wire.available()) {
    buff[i] = Wire.read();
    i++;
  }
  Wire.endTransmission();
  return i;
}

void BH1750_Init(int address) {
  Wire.beginTransmission(address);
  Wire.write(0x10);  // Power on the sensor
  Wire.endTransmission();

  Wire.beginTransmission(address);
  Wire.write(0x11);  // Set measurement mode to continuous high-resolution mode
  Wire.endTransmission();
}