POPX2 RTC show time and display on serial monitor

/*****************************************************
 *   TITLE : REAL TIME CLOCK
 *   CATAGORIES : I2C
 *   CREATED DATE : 22 NOVEMBER 2016
 *   AUTHOR : INNOVATIVE EXPERIMENT CO., LTD. (INEX)
 *   WEBSITE : HTTP://WWW.INEX.CO.TH
 *   DESCRIPTION : Read date and time on MCP7940  (DS1307 Compatible)
 *                 and send data to computer by serial port
 *                 toggle between on and off
 *                 and enable oscillator if disabled
 *                 โปรแกรมแสดงเวลาจาก ZX-RTC ที่ใช้ DS1307
 *                 run on arduino 1.7.10 and POP-X2 board
 *                 โดยส่งค่าทาง Serial Port เพื่อแสดงบนคอมพิวเตอร์
 *                 ถ้าโมดูลไม่ทำงาน จะกำหนดค่าและให้เริ่มทำงาน
******************************************************/
#include <popx2.h>
#include <Wire.h>
#define DEVICE_ADDRESS 0x6F
int second, minute, hour, dayOfWeek,dayOfMonth,month,year;
int second1;
void setup(){
  Serial.begin(9600);
  Wire.begin();
  setDateTime(0, 59, 13, 3, 22, 11, 16);
  setTextSize(2);
}
void loop(){
  getDateTime();
  Serial.print(hour);
  Serial.print(":");
  Serial.print(minute);
  Serial.print(":");
  Serial.print(second);
  Serial.print("   ");
  Serial.print(year);
  Serial.print("/");
  Serial.print(month);
  Serial.print("/");
  Serial.print(dayOfMonth);
  Serial.print("\n\r");
}

byte decToBcd(byte val){  return ((val / 10 * 16) + (val % 10)); } // Convert decimal to BCD function
byte bcdToDec(byte val){  return ((val / 16 * 10) + (val % 16));} // Convert BCD to decimal function
void getDateTime(){
  // Begin I2C transmission with DS1307 address
  Wire.beginTransmission(DEVICE_ADDRESS);
  Wire.write(0x00); // Send register address
  Wire.endTransmission(); // End I2C trasmission
  Wire.requestFrom(DEVICE_ADDRESS, 7); // Request next 7 register address
  // Get date and time
  second1 = Wire.read();
  minute = bcdToDec(Wire.read());
  hour   = bcdToDec(Wire.read() & 0x3f);
  dayOfWeek = bcdToDec(Wire.read());
  dayOfMonth = bcdToDec(Wire.read());
  month   = bcdToDec(Wire.read());
  year = bcdToDec(Wire.read());

  if ((second1&0x80)==0x00){
    Wire.beginTransmission(DEVICE_ADDRESS);
    Wire.write(0x00);
    Wire.write(second1|0x80);
    Wire.endTransmission();
  }
  second=bcdToDec(second1 &0x7F);
}

void setDateTime(int sec, int minu, int hr, int daywk, int daymn, int mn, int yr){
  // Begin I2C transmission with CMPS03 address
  Wire.beginTransmission(DEVICE_ADDRESS);
   Wire.write(0x00);
  // Send date and time to DS1307
  Wire.write(decToBcd(sec));
  Wire.write(decToBcd(minu));
  Wire.write(decToBcd(hr));
  Wire.write(decToBcd(daywk));
  Wire.write(decToBcd(daymn));
  Wire.write(decToBcd(mn));
  Wire.write(decToBcd(yr));

  // End I2C trasmission
  Wire.endTransmission();
}

// Set SQW
void setSQW(boolean st)
{
  // Begin I2C transmission with DS1307 address
  Wire.beginTransmission(DEVICE_ADDRESS);

  // Send register address
  Wire.write(0x07);

  if(st)
  {
    // Enable SQW command
    Wire.write(0x10);
  }
  else
  {
    // Disable SQW command
    Wire.write(0x00);
  }

  // End I2C trasmission
  Wire.endTransmission();
}