A Simple Clock using DS1307 + PIC16F877A
Even I have posted about "DS1307 + PIC16F877A", I didn't have chance to make a real prototype of the clock. I have done only on the simulation software. Today, I have received a comment about that post. ah_bear followed my code and schematic on that post but the clock didn't work. This is because the code on that post is for reading time from DS1307 so there must be some values in the DS1307 before you can read. The solution is simple. Just place setting time codes before reading codes
The schematic of the clock is very simple. Please note that the schematic does not show power supply to the PIC16F877A and the DS1307, you have to connect them by youself. If you are new to PIC/LCD interface please see MikroC "Hello World!" LCD example .
The source code:
//Sample code for
//DS1307 RTC Interfacing with PIC16F877A
//Coded by punkky@gmail.com
//Compiler: mikroC 8.0.0
//http://picnote.blogspot.com
//05/01/2009
//Use with your own risk
unsigned short read_ds1307(unsigned short address );
void write_ds1307(unsigned short address,unsigned short w_data);
unsigned short sec;
unsigned short minute;
unsigned short hour;
unsigned short day;
unsigned short date;
unsigned short month;
unsigned short year;
unsigned short data;
char time[9];
char ddate[11];
unsigned char BCD2UpperCh(unsigned char bcd);
unsigned char BCD2LowerCh(unsigned char bcd);
void main(){
I2C_Init(100000); //DS1307 I2C is running at 100KHz
PORTB = 0;
TRISB = 0; // Configure PORTB as output
TRISC = 0xFF;
Lcd_Init(&PORTB); // Initialize LCD connected to PORTB
Lcd_Cmd(Lcd_CLEAR); // Clear display
Lcd_Cmd(Lcd_CURSOR_OFF); // Turn cursor off
Lcd_Out(1, 1, "TIME:");
Lcd_Out(2, 1, "DATE:");
//Set Time
write_ds1307(0,0x80); //Reset second to 0 sec. and stop Oscillator
write_ds1307(1,0x10); //write min 27
write_ds1307(2,0x01); //write hour 14
write_ds1307(3,0x02); //write day of week 2:Monday
write_ds1307(4,0x05); // write date 17
write_ds1307(5,0x01); // write month 6 June
write_ds1307(6,0x09); // write year 8 --> 2008
write_ds1307(7,0x10); //SQWE output at 1 Hz
write_ds1307(0,0x00); //Reset second to 0 sec. and start Oscillator
while(1)
{
sec=read_ds1307(0); // read second
minute=read_ds1307(1); // read minute
hour=read_ds1307(2); // read hour
day=read_ds1307(3); // read day
date=read_ds1307(4); // read date
month=read_ds1307(5); // read month
year=read_ds1307(6); // read year
time[0] = BCD2UpperCh(hour);
time[1] = BCD2LowerCh(hour);
time[2] = ':';
time[3] = BCD2UpperCh(minute);
time[4] = BCD2LowerCh(minute);
time[5] = ':';
time[6] = BCD2UpperCh(sec);
time[7] = BCD2LowerCh(sec);
time[8] = '\0';
ddate[0] = BCD2UpperCh(date);
ddate[1] = BCD2LowerCh(date);
ddate[2] ='/';
ddate[3] = BCD2UpperCh(month);
ddate[4] = BCD2LowerCh(month);
ddate[5] ='/';
ddate[6] = '2';
ddate[7] = '0';
ddate[8] = BCD2UpperCh(year);
ddate[9] = BCD2LowerCh(year);
ddate[10] = '\0';
Lcd_Out(1,6,time);
Lcd_Out(2,6,ddate);
Delay_ms(50);
}
}
unsigned short read_ds1307(unsigned short address)
{
I2C_Start();
I2C_Wr(0xd0); //address 0x68 followed by direction bit (0 for write, 1 for read) 0x68 followed by 0 --> 0xD0
I2C_Wr(address);
I2C_Repeated_Start();
I2C_Wr(0xd1); //0x68 followed by 1 --> 0xD1
data=I2C_Rd(0);
I2C_Stop();
return(data);
}
unsigned char BCD2UpperCh(unsigned char bcd)
{
return ((bcd >> 4) + '0');
}
unsigned char BCD2LowerCh(unsigned char bcd)
{
return ((bcd & 0x0F) + '0');
}
void write_ds1307(unsigned short address,unsigned short w_data)
{
I2C_Start(); // issue I2C start signal
//address 0x68 followed by direction bit (0 for write, 1 for read) 0x68 followed by 0 --> 0xD0
I2C_Wr(0xD0); // send byte via I2C (device address + W)
I2C_Wr(address); // send byte (address of DS1307 location)
I2C_Wr(w_data); // send data (data to be written)
I2C_Stop(); // issue I2C stop signal
}
Posted by punkky at Monday, January 05, 2009
Topics: Clock, DS1307, Microcontroller, PIC16F877a, Schematic, Source Code
12 comments:
Blue Tear's said...
Great post. But i need help to increase buttons to set time and date. Can you help me with this.
January 6, 2009 10:20 PM
punkky said...
I'm working on the complete clock. I will post the whole things. Please come back later.
January 11, 2009 10:49 AM
Blue Tear's said...
Can you post your new code for the buttons. Thanks
January 15, 2009 8:28 PM
oxoxo said...
thanks for sharing the code.
but i do not understand the datasheet for DS1307 on how to set the time that i want..for example, i want to set the time for 24-hr clock at 0800 or 1900(7p.m). i don get to understand how u write 0x01 as 14 hour (write_ds1307(2,0x01); //write hour 14) and other timing as well.
do advise this asap, a million thanks~!
March 25, 2009 12:33 AM
PIC said...
good program
April 25, 2009 6:53 PM
trungnt said...
Based on your code, I have written code for RTC using buttons to set time and 12 Led 7-Seg to show time (year-month-date-hour-min-sec). Thanks!!!
May 27, 2009 9:53 PM
Chuck said...
Can you help me? This is my first attempt to program a chip.
What to make a red clock for car.
I've been trying to program a pic chip 16f628A for the last month.
For some reason all I get is ERROR hardware not found on COM.
I have down loaded picaxe programming editor.
I purchased the pic programmer.
I have a USB to serial cable.
What is wrong?????
July 14, 2009 4:54 PM
Chuck said...
Me again. You can contact me at sbcm07@hotmail.com
July 15, 2009 3:26 AM
Ranier said...
hi everyone, help me to make add-ons to this circuit.. i will make an alarm clock that will based to the digital clock made... this is my first time to program to a chip. pls help me... here's my email address... ranier21ph@yahoo.com
October 6, 2009 5:32 PM
KENNY said...
may i know wat type of crystal r using?
December 8, 2009 8:16 PM
sarah said...
may i know which software did you used to simulate the circuit and the coding.tq
December 10, 2009 11:22 PM
Minos said...
I've made the schematic, but the simul inisis doesn't work. time is 00:00:00, and date 00:00:2000. can u help me pls?
January 11, 2010 7:58 PM
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The source code:
//Sample code for
//DS1307 RTC Interfacing with PIC16F877A
//Coded by punkky@gmail.com
//Compiler: mikroC 8.0.0
//http://picnote.blogspot.com
//05/01/2009
//Use with your own risk
unsigned short read_ds1307(unsigned short address );
void write_ds1307(unsigned short address,unsigned short w_data);
unsigned short sec;
unsigned short minute;
unsigned short hour;
unsigned short day;
unsigned short date;
unsigned short month;
unsigned short year;
unsigned short data;
char time[9];
char ddate[11];
unsigned char BCD2UpperCh(unsigned char bcd);
unsigned char BCD2LowerCh(unsigned char bcd);
void main(){
I2C_Init(100000); //DS1307 I2C is running at 100KHz
PORTB = 0;
TRISB = 0; // Configure PORTB as output
TRISC = 0xFF;
Lcd_Init(&PORTB); // Initialize LCD connected to PORTB
Lcd_Cmd(Lcd_CLEAR); // Clear display
Lcd_Cmd(Lcd_CURSOR_OFF); // Turn cursor off
Lcd_Out(1, 1, "TIME:");
Lcd_Out(2, 1, "DATE:");
//Set Time
write_ds1307(0,0x80); //Reset second to 0 sec. and stop Oscillator
write_ds1307(1,0x10); //write min 27
write_ds1307(2,0x01); //write hour 14
write_ds1307(3,0x02); //write day of week 2:Monday
write_ds1307(4,0x05); // write date 17
write_ds1307(5,0x01); // write month 6 June
write_ds1307(6,0x09); // write year 8 --> 2008
write_ds1307(7,0x10); //SQWE output at 1 Hz
write_ds1307(0,0x00); //Reset second to 0 sec. and start Oscillator
while(1)
{
sec=read_ds1307(0); // read second
minute=read_ds1307(1); // read minute
hour=read_ds1307(2); // read hour
day=read_ds1307(3); // read day
date=read_ds1307(4); // read date
month=read_ds1307(5); // read month
year=read_ds1307(6); // read year
time[0] = BCD2UpperCh(hour);
time[1] = BCD2LowerCh(hour);
time[2] = ':';
time[3] = BCD2UpperCh(minute);
time[4] = BCD2LowerCh(minute);
time[5] = ':';
time[6] = BCD2UpperCh(sec);
time[7] = BCD2LowerCh(sec);
time[8] = '\0';
ddate[0] = BCD2UpperCh(date);
ddate[1] = BCD2LowerCh(date);
ddate[2] ='/';
ddate[3] = BCD2UpperCh(month);
ddate[4] = BCD2LowerCh(month);
ddate[5] ='/';
ddate[6] = '2';
ddate[7] = '0';
ddate[8] = BCD2UpperCh(year);
ddate[9] = BCD2LowerCh(year);
ddate[10] = '\0';
Lcd_Out(1,6,time);
Lcd_Out(2,6,ddate);
Delay_ms(50);
}
}
unsigned short read_ds1307(unsigned short address)
{
I2C_Start();
I2C_Wr(0xd0); //address 0x68 followed by direction bit (0 for write, 1 for read) 0x68 followed by 0 --> 0xD0
I2C_Wr(address);
I2C_Repeated_Start();
I2C_Wr(0xd1); //0x68 followed by 1 --> 0xD1
data=I2C_Rd(0);
I2C_Stop();
return(data);
}
unsigned char BCD2UpperCh(unsigned char bcd)
{
return ((bcd >> 4) + '0');
}
unsigned char BCD2LowerCh(unsigned char bcd)
{
return ((bcd & 0x0F) + '0');
}
void write_ds1307(unsigned short address,unsigned short w_data)
{
I2C_Start(); // issue I2C start signal
//address 0x68 followed by direction bit (0 for write, 1 for read) 0x68 followed by 0 --> 0xD0
I2C_Wr(0xD0); // send byte via I2C (device address + W)
I2C_Wr(address); // send byte (address of DS1307 location)
I2C_Wr(w_data); // send data (data to be written)
I2C_Stop(); // issue I2C stop signal
}
