#include <Wire.h>

// Set up a serial monitor port and initialize the MCP79400 to run.

void setup()
{
  Wire.begin();                                         // join i2c bus (address optional for master)
  Serial.begin(9600);                              // start serial for output
  
  Wire.beginTransmission(0x6f);   // transmit to device address 111 (0x6F)
  Wire.write(0);                                     // point to internal register “0”
  Wire.write(0x80);                              // Set highest bit to enable 32KHz clock
  Wire.endTransmission(0);             // send bytes and stop transmission
  delay(5);
  
  Wire.beginTransmission(0x6f);   // transmit to device address 111 (0x6F)
  Wire.write(7);                                     // point to internal register “7”
  Wire.write(0x40);                             // make MFP pin an output w/ 1HZ square wave
  Wire.endTransmission(0);            // send bytes and stop transmission
  delay(5);
}

// Main program loop reads MCP79400 registers associated with time/date.

void loop()
{
Wire.beginTransmission(0x6f);   // transmit to device address 111 (0x6F)
Wire.write(0);                                    // point to internal register “0”
Wire.endTransmission();              // send bytes and stop transmission

  Wire.requestFrom(0x6f,6);       // reads bytes from sequential addresses
byte Seconds = Wire.read();     // receive a byte
byte Minutes = Wire.read();     // receive a byte
byte Hours = Wire.read();       // receive a byte
byte Day = Wire.read();         // receive a byte
byte Date = Wire.read();        // receive a byte
byte Month = Wire.read();       // receive a byte
byte Year = Wire.read();        // receive a byte

//Convert BCD seconds to total seconds and send to serial monitor

Serial.print((((Seconds&0x70)>>4)*10)+(Seconds&0x0f));  // print seconds
Serial.println(" seconds");
delay(1000);
}