Horloge temps PCF8583

[Tyller]

Salut tout le monde, Je reviens sur le PCF8583 en ouvrant ce nouveau post pour plus de clarté.

Voila la chose. On a un projet de 2ème année de BTS et j'ai donc un collègue qui doit utiliser ce fameux PCF. Jusqu'à présent, tout fonctionne mais il nous faudrait comprendre le fonctionnement du programme qu'il a put trouver sur le net.

En premier lieu, il y a une fonction nommée date_time_t dt; mais elle n'est définie nulle part, et n'est pas référencée dans l'aide du compilateur qui est PIC CCS.

Voilà, si quelqu'un peu nous éclairer sur ce petit truc, pour le moment.

Je vous met le programme dans le post suivant.
-----

[Tyller]

// PCF8583.C

#ifndef PCF8583_SDA
#define PCF8583_SDA  PIN_C4
#define PCF8583_SCL  PIN_C3
#endif

#use i2c(master, sda=PCF8583_SDA, scl=PCF8583_SCL)

#ifndef PCF8583_WRITE_ADDRESS
#define PCF8583_WRITE_ADDRESS 0xA0
#define PCF8583_READ_ADDRESS  0xA1
#endif

// Register addresses
#define PCF8583_CTRL_STATUS_REG    0x00
#define PCF8583_100S_REG           0x01
#define PCF8583_SECONDS_REG        0x02
#define PCF8583_MINUTES_REG        0x03
#define PCF8583_HOURS_REG          0x04
#define PCF8583_DATE_REG           0x05
#define PCF8583_MONTHS_REG         0x06
#define PCF8583_TIMER_REG          0x07

#define PCF8583_ALARM_CONTROL_REG  0x08
#define PCF8583_ALARM_100S_REG     0x09
#define PCF8583_ALARM_SECS_REG     0x0A
#define PCF8583_ALARM_MINS_REG     0x0B
#define PCF8583_ALARM_HOURS_REG    0x0C
#define PCF8583_ALARM_DATE_REG     0x0D
#define PCF8583_ALARM_MONTHS_REG   0x0E
#define PCF8583_ALARM_TIMER_REG    0x0F

// Use the first NVRAM address for the year byte.
#define PCF8583_YEAR_REG           0x10


// Commands for the Control/Status register.
#define PCF8583_START_COUNTING     0x00
#define PCF8583_STOP_COUNTING      0x80



char const weekday_names[7][10] =
{
{"Sunday"},
{"Monday"},
{"Tuesday"},
{"Wednesday"},
{"Thursday"},
{"Friday"},
{"Saturday"}
};   
               
// This structure defines the user's date and time data.
// The values are stored as unsigned integers.  The user
// should declare a structure of this type in the application
// program. Then the address of the structure should be
// passed to the PCF8583 read/write functions in this
// driver, whenever you want to talk to the chip.
typedef struct
{
int8 seconds;    // 0 to 59
int8 minutes;    // 0 to 59
int8 hours;      // 0 to 23  (24-hour time)
int8 day;        // 1 to 31
int8 month;      // 1 to 12
int8 year;       // 00 to 99
int8 weekday;    // 0 = Sunday, 1 = Monday, etc.
}date_time_t;


//----------------------------------------------
void PCF8583_write_byte(int8 address, int8 data)
{
disable_interrupts(GLOBAL);
i2c_start();
i2c_write(PCF8583_WRITE_ADDRESS);
i2c_write(address);
i2c_write(data);
i2c_stop();
enable_interrupts(GLOBAL);
}   

//----------------------------------------------
int8 PCF8583_read_byte(int8 address)
{
int8 retval;

disable_interrupts(GLOBAL);
i2c_start();
i2c_write(PCF8583_WRITE_ADDRESS);
i2c_write(address);
i2c_start();
i2c_write(PCF8583_READ_ADDRESS);
retval = i2c_read(0);
i2c_stop();
enable_interrupts(GLOBAL);
return(retval);
}   


void PCF8583_init(void)
{
PCF8583_write_byte(PCF8583_CTRL_STATUS_REG,
                              PCF8583_START_COUNTING);
}   

//----------------------------------------------
// This function converts an 8 bit binary value
// to an 8 bit BCD value.
// The input range must be from 0 to 99.

int8 bin2bcd(int8 value)
{
char retval;

retval = 0;

while(1)
  {
   // Get the tens digit by doing multiple subtraction
   // of 10 from the binary value.
   if(value >= 10)
     {
      value -= 10;
      retval += 0x10;
     }
   else // Get the ones digit by adding the remainder.
     {
      retval += value;
      break;
     }
   }

return(retval);
}

//----------------------------------------------
// This function converts an 8 bit BCD value to
// an 8 bit binary value.
// The input range must be from 00 to 99.

char bcd2bin(char bcd_value)
{
char temp;

temp = bcd_value;

// Shifting the upper digit right by 1 is
// the same as multiplying it by 8.
temp >>= 1;

// Isolate the bits for the upper digit.
temp &= 0x78;

// Now return: (Tens * 8) + (Tens * 2) + Ones
return(temp + (temp >> 2) + (bcd_value & 0x0f));

}

//----------------------------------------------
void PCF8583_set_datetime(date_time_t *dt)
{
int8 bcd_sec;
int8 bcd_min;
int8 bcd_hrs;
int8 bcd_day;
int8 bcd_mon;

// Convert the input date/time into BCD values
// that are formatted for the PCF8583 registers. 
bcd_sec = bin2bcd(dt->seconds);
bcd_min = bin2bcd(dt->minutes);
bcd_hrs = bin2bcd(dt->hours);   
bcd_day = bin2bcd(dt->day) | (dt->year << 6);
bcd_mon = bin2bcd(dt->month) | (dt->weekday << 5);

// Stop the RTC from counting, before we write to
// the date and time registers.
PCF8583_write_byte(PCF8583_CTRL_STATUS_REG,
                              PCF8583_STOP_COUNTING);

// Write to the date and time registers.  Disable interrupts
// so they can't disrupt the i2c operations.
disable_interrupts(GLOBAL);
i2c_start();
i2c_write(PCF8583_WRITE_ADDRESS);
i2c_write(PCF8583_100S_REG);   // Start at 100's reg.   
i2c_write(0x00);               // Set 100's reg = 0
i2c_write(bcd_sec); 
i2c_write(bcd_min);
i2c_write(bcd_hrs);   
i2c_write(bcd_day);
i2c_write(bcd_mon);
i2c_stop();
enable_interrupts(GLOBAL);

// Write the year byte to the first NVRAM location.
// Leave it in binary format.
PCF8583_write_byte(PCF8583_YEAR_REG, dt->year);

// Now allow the PCF8583 to start counting again.
PCF8583_write_byte(PCF8583_CTRL_STATUS_REG,
                              PCF8583_START_COUNTING);
}

//----------------------------------------------
// Read the Date and Time from the hardware registers
// in the PCF8583.   We don't have to disable counting
// during read operations, because according to the data
// sheet, if any of the lower registers (1 to 7) is read,
// all of them are loaded into "capture" registers.
// All further reading within that cycle is done from
// those registers.

void PCF8583_read_datetime(date_time_t *dt)
{
int8 year_bits;
int8 year;

int8 bcd_sec;
int8 bcd_min;
int8 bcd_hrs;
int8 bcd_day;
int8 bcd_mon;

// Disable interrupts so the i2c process is not disrupted.
disable_interrupts(GLOBAL);

// Read the date/time registers inside the PCF8583.
i2c_start();
i2c_write(PCF8583_WRITE_ADDRESS);
i2c_write(PCF8583_SECONDS_REG);   // Start at seconds reg.
i2c_start();
i2c_write(PCF8583_READ_ADDRESS);

bcd_sec = i2c_read();     
bcd_min = i2c_read();     
bcd_hrs = i2c_read(); 
bcd_day = i2c_read();
bcd_mon = i2c_read(0);
i2c_stop();

enable_interrupts(GLOBAL);

// Convert the date/time values from BCD to
// unsigned 8-bit integers.  Unpack the bits
// in the PCF8583 registers where required.
dt->seconds = bcd2bin(bcd_sec);     
dt->minutes = bcd2bin(bcd_min);     
dt->hours   = bcd2bin(bcd_hrs & 0x3F); 
dt->day     = bcd2bin(bcd_day & 0x3F);
dt->month   = bcd2bin(bcd_mon & 0x1F);
dt->weekday = bcd_mon >> 5;
year_bits   = bcd_day >> 6;   

// Read the year byte from NVRAM.
// This is an added feature of this driver.
year = PCF8583_read_byte(PCF8583_YEAR_REG);

// Check if the two "year bits" were incremented by
// the PCF8583.  If so, increment the 8-bit year
// byte (read from NVRAM) by the same amount.
while(year_bits != (year & 3))
      year++;

dt->year = year;

// Now update the year byte in the NVRAM
// inside the PCF8583.
PCF8583_write_byte(PCF8583_YEAR_REG, year);

}

[invite5b66c9bd]

slt a ts.
je veux afficher l'Heure et la date sur un lcd a travers un pcf8583 et un PIC 16F877.
je veux avoir le programme en language PICBASIC.
de l'aide SVP c'est urg
merci d'avance

[Tyller]

Salut Chaffa, il n'y a pas assez de précision dans ta question pour que l'on puisse y répondre.
Quel est le LCD utilisé, comment est'il branché sur le pic, est ce que tu utilise un autre composant pour passer du pic au LCD etc..

Suivant le LCD et suivant mes souvenir, s'il est directement branché sur le pic, tu à une fonction qui te permet d'écrire ce que tu veux du genre printf(); mais bon, le basic ça remonte a 3 ans déjà, m'en souviens plus.

[A voir en vidéo sur Futura]