// I2C Light Sensor

#include <Wire.h>

#define address 0x44 // A0 = L

void setup()
{
  Wire.begin(); // join i2c bus (address optional for master)
  pinMode(3, OUTPUT);  // LED pro blikani, aby bylo videt, ze to neco dela
  Serial.begin(9600);  // Zmerena intenzita osvetleni se bude vypisovat na seriovou linku
}

int data = 0;

void loop()
{
  int lux=0;
  
  Serial.print("lux=");

  // Setup device
  Wire.beginTransmission(address); 
  Wire.send(0x00);            // sends address
  Wire.send(0b11000000);      // setup (eye light sensing; measurement range 2 [4000 lx])
  Wire.endTransmission();     // stop transmitting

  // Delay for measurement
  digitalWrite(3, HIGH);   // set the LED on
  delay(500);
  digitalWrite(3, LOW);    // set the LED off
  delay(500);


  //  Connect to device and set register address
  Wire.beginTransmission(address); 
  Wire.send(0x00);            // sends address
  Wire.endTransmission();     // stop transmitting
  //  Connect to device and request one byte
  Wire.beginTransmission(address);
  Wire.requestFrom(address, 1);
  data = Wire.receive();
  Wire.endTransmission();     // stop transmitting
//  Serial.print(data, HEX);

//  Serial.print(" LSB=");
  //  Connect to device and set register address
  Wire.beginTransmission(address); 
  Wire.send(0x01);            // sends address
  Wire.endTransmission();     // stop transmitting
  //  Connect to device and request one byte
  Wire.beginTransmission(address);
  Wire.requestFrom(address, 1);
  data = Wire.receive();
  Wire.endTransmission();     // stop transmitting
//  Serial.print(data, HEX);
  lux=data;

//  Serial.print(" MSB=");  
  //  Connect to device and set register address
  Wire.beginTransmission(address);
  Wire.send(0x02);            // sends address
  Wire.endTransmission();     // stop transmitting
  //  Connect to device and request one byte
  Wire.beginTransmission(address);
  Wire.requestFrom(address, 1);
  data = Wire.receive();
  Wire.endTransmission();     // stop transmitting
//  Serial.print(data, HEX);
  lux+=data*256;

  Serial.print((unsigned)lux, DEC);

  Serial.print(" luxIR=");

  // Setup device
  Wire.beginTransmission(address); 
  Wire.send(0x00);            // sends address
  Wire.send(0b11100000);      // setup (eye light sensing; measurement range 2 [4000 lx])
  Wire.endTransmission();     // stop transmitting

  // Delay for measurement
  digitalWrite(3, HIGH);   // set the LED on
  delay(500);
  digitalWrite(3, LOW);    // set the LED off
  delay(500);


  //  Connect to device and set register address
  Wire.beginTransmission(address); 
  Wire.send(0x00);            // sends address
  Wire.endTransmission();     // stop transmitting
  //  Connect to device and request one byte
  Wire.beginTransmission(address);
  Wire.requestFrom(address, 1);
  data = Wire.receive();
  Wire.endTransmission();     // stop transmitting
//  Serial.print(data, HEX);

//  Serial.print(" LSB=");
  //  Connect to device and set register address
  Wire.beginTransmission(address); 
  Wire.send(0x01);            // sends address
  Wire.endTransmission();     // stop transmitting
  //  Connect to device and request one byte
  Wire.beginTransmission(address);
  Wire.requestFrom(address, 1);
  data = Wire.receive();
  Wire.endTransmission();     // stop transmitting
//  Serial.print(data, HEX);
  lux=data;

//  Serial.print(" MSB=");  
  //  Connect to device and set register address
  Wire.beginTransmission(address);
  Wire.send(0x02);            // sends address
  Wire.endTransmission();     // stop transmitting
  //  Connect to device and request one byte
  Wire.beginTransmission(address);
  Wire.requestFrom(address, 1);
  data = Wire.receive();
  Wire.endTransmission();     // stop transmitting
//  Serial.print(data, HEX);
  lux+=data*256;

  Serial.println((unsigned)lux, DEC);

}