Arduino: RTC DS3231 PC Sync

Sumber: http://playground.arduino.cc/Code/time

Siapkan Library

Download dari

• http://playground.arduino.cc/uploads/Code/Time.zip

Extrak

cd /usr/share/arduino/libraries/

atau

cd ~/Arduino/libraries

wget http://playground.arduino.cc/uploads/Code/Time.zip
unzip Time.zip
cd Time
gedit DateStrings.cpp 

Tambahkan di

char   > char  const
PGM_P  > PGM_P const

Code

#include <Time.h>  

#define TIME_MSG_LEN  11   // time sync to PC is HEADER followed by Unix time_t as ten ASCII digits
#define TIME_HEADER  'T'   // Header tag for serial time sync message
#define TIME_REQUEST  7    // ASCII bell character requests a time sync message

// T1262347200  //noon Jan 1 2010

void setup()  {
  Serial.begin(9600);
}

void loop(){    
  if(Serial.available() )
  {
    processSyncMessage();
  }
  if(timeStatus() == timeNotSet)
    Serial.println("waiting for sync message");
  else    
      digitalClockDisplay();  
  delay(1000);
}

void digitalClockDisplay(){
  // digital clock display of the time
  Serial.print(hour());
  printDigits(minute());
  printDigits(second());
  Serial.print(" ");
  Serial.print(day());
  Serial.print(" ");
  Serial.print(month());
  Serial.print(" ");
  Serial.print(year());
  Serial.println();
}

void printDigits(int digits){
  // utility function for digital clock display: prints preceding colon and leading 0
  Serial.print(":");
  if(digits < 10)
    Serial.print('0');
  Serial.print(digits);
}

void processSyncMessage() {
  // if time sync available from serial port, update time and return true
  while(Serial.available() >=  TIME_MSG_LEN ){  // time message consists of header & 10 ASCII digits
    char c = Serial.read() ;
    Serial.print(c);  
    if( c == TIME_HEADER ) {      
      time_t pctime = 0;
      for(int i=0; i < TIME_MSG_LEN -1; i++){  
        c = Serial.read();          
        if( c >= '0' && c <= '9'){  
          pctime = (10 * pctime) + (c - '0') ; // convert digits to a number    
        }
      }  
      setTime(pctime);   // Sync Arduino clock to the time received on the serial port
    }  
  }
}

PC Sync

Lakukan

date +T%s\n > /dev/ttyACM0

Untuk mensinkronisasi waktu

Referensi

• http://playground.arduino.cc/Code/time