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micr_brain
Joined: 29 Jun 2007
Posts: 5
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| Ds1307 12-hour format. |
 Posted: Thu Jan 24, 2008 8:29 am |
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Dear Electronics friends.
I want to display on lcd the current date and the time with 12-hour format.
Please tell me , how set 12-hour format mode.
Thanks micr_brain. |
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Humberto
Joined: 08 Sep 2003
Posts: 1215
Location: Buenos Aires, La Reina del Plata
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| Posted: Thu Jan 24, 2008 9:13 am |
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http://datasheets.maxim-ic.com/en/ds/DS1307.pdf
From page 8:
"The DS1307 can be run in either 12-hour or 24-hour mode. Bit 6 of the hours register
is defined as the 12-hour or 24-hour mode-select bit.
When high, the 12-hour mode is selected.
In the 12-hour mode, bit 5 is the AM/PM bit with logic high being PM.
In the 24-hour mode, bit 5 is the second 10-hour bit (20 to 23 hours).
The hours value must be re-entered whenever the 12/24-hour mode bit is changed."
Humberto |
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micr_brain
Joined: 29 Jun 2007
Posts: 5
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| Posted: Sat Jan 26, 2008 8:52 pm |
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Thanks Humberto.
Please tell me how enable 12-hour format with this file
micro_brain
| Code: | #include <16F876a.h>
#include <ds1307.h>
#fuses NOWDT,XT, PUT, NOPROTECT, BROWNOUT ,NODEBUG ,NOLVP
#use delay(clock=4000000)
#use rs232(baud=9600,parity=N,xmit=PIN_A0,rcv=PIN_A1,bits=8)
#zero_ram
int DATE,MTH,YR,HR,MT,SECDS,DOW;
void main() {
setup_adc_ports(NO_ANALOGS);
setup_adc(ADC_OFF);
setup_spi(FALSE);
setup_timer_0(RTCC_INTERNAL|RTCC_DIV_1);
setup_comparator(NC_NC_NC_NC);
setup_vref(FALSE);
ds1307_init();
while(1){
ds1307_get_time(HR,MT,SECDS);
ds1307_get_date(DATE,MTH,YR,DOW);
printf("\rTime %2D:%02D:%02D",HR,MT,SECDS);
printf(" Date %2D/%02D/%02D",DATE,MTH,YR);
delay_ms(100);
if(!input(PIN_C0 ))
ds1307_set_date_time(28,1,8,2,11,50,0); // Time 11:50:00 Date 28/01/08
}
}
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this is 24-hour format. working Perfectly.
but I want to change this code to 12-hour format and (AM/PM) indication
Please help me.
ds1307.h
| Code: |
//////////////////////////////////////////////////////////////////////////////////
/// DS1307.C ///
/// Driver for Real Time Clock ///
/// ///
/// ds1307_init() - Enable oscillator without clearing the seconds register -///
/// used when PIC loses power and DS1307 run from 3V BAT ///
/// - Disable squarewave output ///
/// ///
/// ds1307_set_date_time(day,mth,year,dow,hour,min,sec) Set the date/time ///
/// ///
/// ds1307_get_date(day,mth,year,dow) Get the date ///
/// ///
/// ds1307_get_time(hr,min,sec) Get the time ///
/// ///
////////////////////////////////////////////////////////////////////////////////
#use delay(clock=4000000)
#define RTC_SDA PIN_C4
#define RTC_SCL PIN_C3
#use i2c(master, sda=RTC_SDA, scl=RTC_SCL)
BYTE bin2bcd(BYTE binary_value);
BYTE bcd2bin(BYTE bcd_value);
void ds1307_init(void)
{
BYTE seconds = 0;
i2c_start();
i2c_write(0xD0); // WR to RTC
i2c_write(0x00); // REG 0
i2c_start();
i2c_write(0xD1); // RD from RTC
seconds = bcd2bin(i2c_read(0)); // Read current "seconds" in DS1307
i2c_stop();
seconds &= 0x7F;
delay_us(3);
i2c_start();
i2c_write(0xD0); // WR to RTC
i2c_write(0x00); // REG 0
i2c_write(bin2bcd(seconds)); // Start oscillator with current "seconds value
i2c_start();
i2c_write(0xD0); // WR to RTC
i2c_write(0x07); // Control Register
i2c_write(0x80); // Disable squarewave output pin
i2c_stop();
}
void ds1307_set_date_time(BYTE day, BYTE mth, BYTE year, BYTE dow, BYTE hr, BYTE min, BYTE sec)
{
sec &= 0x7F;
hr &= 0x3F;
i2c_start();
i2c_write(0xD0); // I2C write address
i2c_write(0x00); // Start at REG 0 - Seconds
i2c_write(bin2bcd(sec)); // REG 0
i2c_write(bin2bcd(min)); // REG 1
i2c_write(bin2bcd(hr)); // REG 2
i2c_write(bin2bcd(dow)); // REG 3
i2c_write(bin2bcd(day)); // REG 4
i2c_write(bin2bcd(mth)); // REG 5
i2c_write(bin2bcd(year)); // REG 6
i2c_write(0x80); // REG 7 - Disable squarewave output pin
i2c_stop();
}
void ds1307_get_date(BYTE &day, BYTE &mth, BYTE &year, BYTE &dow)
{
i2c_start();
i2c_write(0xD0);
i2c_write(0x03); // Start at REG 3 - Day of week
i2c_start();
i2c_write(0xD1);
dow = bcd2bin(i2c_read() & 0x7f); // REG 3
day = bcd2bin(i2c_read() & 0x3f); // REG 4
mth = bcd2bin(i2c_read() & 0x1f); // REG 5
year = bcd2bin(i2c_read(0)); // REG 6
i2c_stop();
}
void ds1307_get_time(BYTE &hr, BYTE &min, BYTE &sec)
{
i2c_start();
i2c_write(0xD0);
i2c_write(0x00); // Start at REG 0 - Seconds
i2c_start();
i2c_write(0xD1);
sec = bcd2bin(i2c_read() & 0x7f);
min = bcd2bin(i2c_read() & 0x7f);
hr = bcd2bin(i2c_read(0) & 0x3f);
i2c_stop();
}
BYTE bin2bcd(BYTE binary_value)
{
BYTE temp;
BYTE retval;
temp = binary_value;
retval = 0;
while(1)
{
// Get the tens digit by doing multiple subtraction
// of 10 from the binary value.
if(temp >= 10)
{
temp -= 10;
retval += 0x10;
}
else // Get the ones digit by adding the remainder.
{
retval += temp;
break;
}
}
return(retval);
}
// Input range - 00 to 99.
BYTE bcd2bin(BYTE bcd_value)
{
BYTE temp;
temp = bcd_value;
// Shifting upper digit right by 1 is same as multiplying 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));
}
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Thanks |
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