DS 1307

Le module DS 1307 s’utilise via l’interface WIRE qui permet de communiquer avec les puces (protocole I2C).

Board	I2C / TWI pins
Uno, Ethernet	A4 (SDA), A5 (SCL)
Mega2560	20 (SDA), 21 (SCL)
Leonardo	2 (SDA), 3 (SCL)
Due	20 (SDA), 21 (SCL), SDA1, SCL1

Connectez la broche VCC sur la broche 5v de la carte Arduino et la broche GND sur GND.

 

Pour utiliser cette interface, il faut trouver l’adresse de la puce :

 // i2c_scanner  
 // This sketch tests the standard 7-bit addresses  
 // Devices with higher bit address might not be seen properly.  
 //------------------------------------------------------------  
 // You can plug and unplug device during the test  
 // Line SDA plug in UNO pin Analog 4 / Mega 44  
 // line SCL plug in UNO pin Analog 5 / Mega 43  
 #include <Wire.h>  
 void setup()  
 {  
  Wire.begin();  
  Serial.begin(9600);  
  Serial.println("\nI2C Scanner");  
 }  
 void loop()  
 {  
  byte error, address;  
  int nDevices;  
  Serial.println("Scanning...");  
  nDevices = 0;  
  for(address = 1; address < 127; address++ )   
  {  
   // The i2c_scanner uses the return value of  
   // the Write.endTransmisstion to see if  
   // a device did acknowledge to the address.  
   Wire.beginTransmission(address);  
   error = Wire.endTransmission();  
   if (error == 0)  
   {  
    Serial.print("I2C device found at address 0x");  
    if (address<16)   
     Serial.print("0");  
    Serial.print(address,HEX);  
    Serial.println(" !");  
    nDevices++;  
   }  
   else if (error==4)   
   {  
    Serial.print("Unknow error at address 0x");  
    if (address<16)   
     Serial.print("0");  
    Serial.println(address,HEX);  
   }    
  }  
  if (nDevices == 0)  
   Serial.println("No I2C devices found\n");  
  else  
   Serial.println("done\n");  
  delay(5000);      // wait 5 seconds for next scan  
 }  

L’adresse données est : I2C device found at address 0x68 !

Pour mettre à l’heure (et à la date !) le module :

 #include "Wire.h"  
 #define DS1307_ADDRESS 0x68  
 byte zero = 0x00; //workaround for issue #527  
 void setup(){  
  Wire.begin();  
  Serial.begin(9600);  
  setDateTime(); //MUST CONFIGURE IN FUNCTION  
 }  
 void loop(){  
  printDate();  
  delay(1000);  
 }  
 void setDateTime(){  
  byte second =   45; //0-59  
  byte minute =   40; //0-59  
  byte hour =    16; //0-23  
  byte weekDay =   6; //1-7  
  byte monthDay =  23; //1-31  
  byte month =    11; //1-12  
  byte year =    13; //0-99  
  Wire.beginTransmission(DS1307_ADDRESS);  
  Wire.write(zero); //stop Oscillator  
  Wire.write(decToBcd(second));  
  Wire.write(decToBcd(minute));  
  Wire.write(decToBcd(hour));  
  Wire.write(decToBcd(weekDay));  
  Wire.write(decToBcd(monthDay));  
  Wire.write(decToBcd(month));  
  Wire.write(decToBcd(year));  
  Wire.write(zero); //start   
  Wire.endTransmission();  
 }  
 byte decToBcd(byte val){  
 // Convert normal decimal numbers to binary coded decimal  
  return ( (val/10*16) + (val%10) );  
 }  
 byte bcdToDec(byte val) {  
 // Convert binary coded decimal to normal decimal numbers  
  return ( (val/16*10) + (val%16) );  
 }  
 void printDate(){  
  // Reset the register pointer  
  Wire.beginTransmission(DS1307_ADDRESS);  
  Wire.write(zero);  
  Wire.endTransmission();  
  Wire.requestFrom(DS1307_ADDRESS, 7);  
  int second = bcdToDec(Wire.read());  
  int minute = bcdToDec(Wire.read());  
  int hour = bcdToDec(Wire.read() & 0b111111); //24 hour time  
  int weekDay = bcdToDec(Wire.read()); //0-6 -> sunday - Saturday  
  int monthDay = bcdToDec(Wire.read());  
  int month = bcdToDec(Wire.read());  
  int year = bcdToDec(Wire.read());  
  //print the date EG  3/1/11 23:59:59  
  Serial.print(month);  
  Serial.print("/");  
  Serial.print(monthDay);  
  Serial.print("/");  
  Serial.print(year);  
  Serial.print(" ");  
  Serial.print(hour);  
  Serial.print(":");  
  Serial.print(minute);  
  Serial.print(":");  
  Serial.println(second);  
 } 

Code pour afficher l’heure et la date :

 void printDate() {  
  // Reset the register pointer  
  Wire.beginTransmission(DS1307_ADDRESS);  
  byte zero = 0x00;  
  Wire.write(zero);  
  Wire.endTransmission();  
  Wire.requestFrom(DS1307_ADDRESS, 7);  
  int second = bcdToDec(Wire.read());  
  int minute = bcdToDec(Wire.read());  
  int hour = bcdToDec(Wire.read() & 0b111111); //24 hour time  
  int weekDay = bcdToDec(Wire.read()); //0-6 -> sunday - Saturday  
  int monthDay = bcdToDec(Wire.read());  
  int month = bcdToDec(Wire.read());  
  int year = bcdToDec(Wire.read());  
  String sMessage, sSec, sMin, sHour, sDay, sMonth, sYear;  
  //print the date  
  sMessage = sNb(monthDay) + "/" + sNb(month) + "/" + sNb(year) + " " + sNb(hour) + ":" + sNb(minute) + ":" + sNb(second);  
  Serial.println(sMessage);  
 }  
 byte bcdToDec(byte val) {  
  // Convert binary coded decimal to normal decimal numbers  
  return ( (val / 16 * 10) + (val % 16) );  
 }  
 String sNb(int nNb)  
 { if (nNb < 10)  
   return "O" + String(nNb);  
  else  
   return String(nNb);  
 }  

Le code pour mettre à jour la date et l’heure en fonction d’une chaîne texte est ici