The following video shows what I'm going to do:
Real time clock using PIC16F877A microcontroller and DS1307 serial RTC
About DS1307 RTC IC:
The DS1307 is an 8-pin integrated circuit uses I2C communication protocol to communicate with master device which is in our case the PIC16F877A microcontroller. This small chip can count seconds, minutes, hours, day, date, month and year with leap-year up to year 2100.
The DS1307 receives and transfers data (clock data and calendar data) as BCD format, so after receiving data we have to convert these data into decimal data, and before writing data to the DS1307 we have to convert this data from decimal to BCD format. For example we have the BCD number 33, converting this number into decimal gives 21.
The following image shows the DS1307 pin configurations:
The DS1307 uses an external 32.768KHz crystal and there is no need to add any resistors or capacitors with it.
More informations in the DS1307 RTC datasheet.
RTC with 2 alarms using PIC16F877A and DS1307 circuit:
Project circuit schematic is shown below.
- PIC16F877A Microcontroller
- DS1307
- 2004 (20x4) LCD
- 3V Cell Battery
- 8MHz and 32.768KHz crystal oscillators
- 2 x 22pF capacitors
- 3 x 10K resistors
- 10K Potentiometer
- 470Ohm resistor
- 3 Buttons
- LED (For Alarm 1)
- Buzzer (For Alarm 2)
- +5V Power Supply
- Protoboard
- Jumper Wires
This is the full code of this project.....It is easy! be patient!
// Real time clock with alarm using PIC16F877A and DS1307 RTCC CCS C code // http://ccspicc.blogspot.com/ // electronnote@gmail.com //LCD module connections #define LCD_RS_PIN PIN_D0 #define LCD_RW_PIN PIN_D1 #define LCD_ENABLE_PIN PIN_D2 #define LCD_DATA4 PIN_D3 #define LCD_DATA5 PIN_D4 #define LCD_DATA6 PIN_D5 #define LCD_DATA7 PIN_D6 //End LCD module connections #include <16F877A.h> #fuses HS,NOWDT,NOPROTECT,NOLVP #use delay(clock = 8000000) #include <lcd.c> #use fast_io(B) #use I2C(master, I2C1, FAST = 100000) #use pwm (PWM1, FREQUENCY = 2400Hz, DUTY = 50, PWM_OFF) short alarm1_status, alarm2_status; char time[] = "TIME: : : "; char calendar[] = " / /20 "; char alarm1[] = "ALARM1: : :00 "; char alarm2[] = "ALARM2: : :00 "; unsigned int8 second, second10, minute, minute10, hour, hour10, date, date10, month, month10, year, year10, day, alarm1_minute, alarm1_hour, alarm2_minute, alarm2_hour; void ds1307_display(){ second10 = (second & 0x70) >> 4; second = second & 0x0F; minute10 = (minute & 0x70) >> 4; minute = minute & 0x0F; hour10 = (hour & 0x30) >> 4; hour = hour & 0x0F; date10 = (date & 0x30) >> 4; date = date & 0x0F; month10 = (month & 0x10) >> 4; month = month & 0x0F; year10 = (year & 0xF0) >> 4; year = year & 0x0F; time[16] = second + 48; time[15] = second10 + 48; time[13] = minute + 48; time[12] = minute10 + 48; time[10] = hour + 48; time[9] = hour10 + 48; calendar[9] = year + 48; calendar[8] = year10 + 48; calendar[4] = month + 48; calendar[3] = month10 + 48; calendar[1] = date + 48; calendar[0] = date10 + 48; lcd_gotoxy(1, 1); // Go to column 1 row 1 printf(lcd_putc, time); // Display time lcd_gotoxy(1, 2); // Go to column 1 row 2 switch(day){ case 1: lcd_putc("DATE:Sun "); break; case 2: lcd_putc("DATE:Mon "); break; case 3: lcd_putc("DATE:Tue "); break; case 4: lcd_putc("DATE:Wed "); break; case 5: lcd_putc("DATE:Thu "); break; case 6: lcd_putc("DATE:Fri "); break; case 7: lcd_putc("DATE:Sat "); break;} lcd_gotoxy(10, 2); // Go to column 10 row 2 printf(lcd_putc, calendar); // Display calendar } void alarm_display(){ // Display alarms info lcd_gotoxy(21, 1); // Go to column 1 row 3 if(alarm1_status){ alarm1[13] = alarm1_minute % 10 + 48; alarm1[12] = alarm1_minute/10 + 48; alarm1[10] = alarm1_hour%10 + 48; alarm1[9] = alarm1_hour/10 + 48; printf(lcd_putc, alarm1);} else lcd_putc("ALARM1: OFF "); lcd_gotoxy(21, 2); if(alarm2_status){ alarm2[13] = alarm2_minute % 10 + 48; alarm2[12] = alarm2_minute/10 + 48; alarm2[10] = alarm2_hour%10 + 48; alarm2[9] = alarm2_hour/10 + 48; lcd_gotoxy(21, 2); // Go to column 1 row 4 printf(lcd_putc, alarm2);} else lcd_putc("ALARM2: OFF "); } void ds1307_write(unsigned int8 address, data_){ i2c_start(); // Start I2C i2c_write(0xD0); // DS1307 address i2c_write(address); // Send register address i2c_write(data_); // Write data to the selected register i2c_stop(); // Stop I2C } void ds1307_read(){ i2c_start(); // Start I2C i2c_write(0xD0); // DS1307 address i2c_write(0); // Send register address i2c_start(); // Restart I2C i2c_write(0xD1); // Initialize data read second =i2c_read(1); // Read seconds from register 0 minute =i2c_read(1); // Read minuts from register 1 hour = i2c_read(1); // Read hour from register 2 day = i2c_read(1); // Read day from register 3 date = i2c_read(1); // Read date from register 4 month = i2c_read(1); // Read month from register 5 year = i2c_read(0); // Read year from register 6 i2c_stop(); // Stop I2C } void alarm_check(){ if((alarm1_minute == ((minute & 0x0F) + (minute >> 4) * 10)) && (alarm1_hour == ((hour & 0x0F) + (hour >> 4) * 10)) && (second == 0) && alarm1_status) output_high(PIN_B3); if((alarm2_minute == ((minute & 0x0F) + (minute >> 4) * 10)) && (alarm2_hour == ((hour & 0x0F) + (hour >> 4) * 10)) && (second == 0) && alarm2_status) pwm_on(); } void main(){ port_b_pullups(TRUE); // Enable PORTB pull-ups output_b(0); set_tris_b(7); // Configure RB0 & RB1 as inputs lcd_init(); // Initialize LCD module lcd_putc('\f'); // LCD clear while(TRUE){ if(input(PIN_B0) == 0){ // Convert BCD to decimal minute = minute + minute10 * 10; hour = hour + hour10 * 10; date = date + date10 * 10; month = month + month10 * 10; year = year + year10 * 10; // End conversion lcd_gotoxy(1, 1); // Go to column 1 row 1 lcd_putc(" Minutes: "); lcd_gotoxy(1, 2); lcd_putc(" "); delay_ms(200); while(TRUE){ if(input(PIN_B1) == 0) minute++; if(minute > 59) minute = 0; lcd_gotoxy(10, 2); // Go to column 10 row 2 printf(lcd_putc,"%02u", minute); if(input(PIN_B0) == 0) break; delay_ms(200); } lcd_gotoxy(7, 1); // Go to column 7 row 1 lcd_putc(" Hour: "); lcd_gotoxy(10, 2); // Go to column 10 row 2 lcd_putc(" "); delay_ms(200); while(TRUE){ if(input(PIN_B1) == 0) hour++; if(hour > 23) hour = 0; lcd_gotoxy(10, 2); // Go to column 10 row 2 printf(lcd_putc,"%02u", hour); if(input(PIN_B0) == 0) break; delay_ms(200); } lcd_gotoxy(9, 1); // Go to column 9 row 1 lcd_putc("Day: "); lcd_gotoxy(10, 2); // Go to column 10 row 2 lcd_putc(" "); delay_ms(200); while(TRUE){ if(input(PIN_B1) == 0) day++; if(day > 7) day = 1; lcd_gotoxy(6, 2); // Go to column 6 row 2 switch(day){ case 1: lcd_putc(" Sunday "); break; case 2: lcd_putc(" Monday "); break; case 3: lcd_putc(" Tuesday "); break; case 4: lcd_putc("Wednesday"); break; case 5: lcd_putc("Thursday "); break; case 6: lcd_putc(" Friday "); break; case 7: lcd_putc(" Saturday"); break;} if(input(PIN_B0) == 0) break; delay_ms(200); } lcd_gotoxy(9, 1); // Go to column 9 row 1 lcd_putc("Date:"); lcd_gotoxy(6, 2); // Go to column 6 row 2 lcd_putc(" "); delay_ms(200); while(TRUE){ if(input(PIN_B1) == 0) date++; if(date > 31) date = 1; lcd_gotoxy(10, 2); // Go to column 10 row 2 printf(lcd_putc,"%02u", date); if(input(PIN_B0) == 0) break; delay_ms(200); } lcd_gotoxy(8, 1); // Go to column 8 row 1 lcd_putc("Month"); lcd_gotoxy(10, 2); // Go to column 10 row 2 lcd_putc(" "); delay_ms(200); while(TRUE){ if(input(PIN_B1) == 0) month++; if(month > 12) month = 1; lcd_gotoxy(10, 2); // Go to column 10 row 2 printf(lcd_putc,"%02u", month); if(input(PIN_B0) == 0) break; delay_ms(200); } lcd_gotoxy(8, 1); lcd_putc(" Year"); lcd_gotoxy(9, 2); lcd_putc("20 "); delay_ms(200); while(TRUE){ if(input(PIN_B1) == 0) year++; if(year > 99) year = 0; lcd_gotoxy(11, 2); printf(lcd_putc,"%02u", year); if(input(PIN_B0) == 0){ // Convert decimal to BCD minute = ((minute/10) << 4) + (minute % 10); hour = ((hour/10) << 4) + (hour % 10); date = ((date/10) << 4) + (date % 10); month = ((month/10) << 4) + (month % 10); year = ((year/10) << 4) + (year % 10); // End conversion ds1307_write(1, minute); ds1307_write(2, hour); ds1307_write(3, day); ds1307_write(4, date); ds1307_write(5, month); ds1307_write(6, year); ds1307_write(0, 0); delay_ms(200); break; } delay_ms(200); } } if(input(PIN_B2) == 0){ lcd_gotoxy(21, 1); lcd_putc(" ALARM1: "); lcd_gotoxy(21, 2); lcd_putc(" "); delay_ms(200); while(TRUE){ ds1307_read(); ds1307_display(); if(input(PIN_B1) == 0) alarm1_status++; if(alarm1_status){ lcd_gotoxy(30, 2); lcd_putc("ON ");} else{ lcd_gotoxy(30, 2); lcd_putc("OFF");} if(input(PIN_B2) == 0) break; delay_ms(200);} if(alarm1_status){ lcd_gotoxy(21, 1); lcd_putc(" ALARM1 Minutes:"); lcd_gotoxy(21, 2); lcd_putc(" "); delay_ms(200); while(TRUE){ ds1307_read(); ds1307_display(); if(input(PIN_B1) == 0) alarm1_minute++; if(alarm1_minute > 59) alarm1_minute = 0; lcd_gotoxy(30, 2); printf(lcd_putc,"%02u", alarm1_minute); if(input(PIN_B2) == 0) break; delay_ms(200); } lcd_gotoxy(21, 1); lcd_putc(" ALARM1 Hour: "); lcd_gotoxy(21, 2); lcd_putc(" "); delay_ms(200); while(TRUE){ ds1307_read(); ds1307_display(); if(input(PIN_B1) == 0) alarm1_hour++; if(alarm1_hour > 23) alarm1_hour = 0; lcd_gotoxy(30, 2); printf(lcd_putc,"%02u", alarm1_hour); if(input(PIN_B2) == 0) break; delay_ms(200); }} lcd_gotoxy(21, 1); lcd_putc(" ALARM2: "); lcd_gotoxy(21, 2); lcd_putc(" "); delay_ms(200); while(TRUE){ ds1307_read(); ds1307_display(); if(input(PIN_B1) == 0) alarm2_status++; if(alarm2_status){ lcd_gotoxy(30, 2); lcd_putc("ON ");} else{ lcd_gotoxy(30, 2); lcd_putc("OFF");} if(input(PIN_B2) == 0) break; delay_ms(200);} if(alarm2_status){ lcd_gotoxy(21, 1); lcd_putc(" ALARM2 Minutes:"); lcd_gotoxy(21, 2); lcd_putc(" "); delay_ms(200); while(TRUE){ ds1307_read(); ds1307_display(); if(input(PIN_B1) == 0) alarm2_minute++; if(alarm2_minute > 59) alarm2_minute = 0; lcd_gotoxy(30, 2); printf(lcd_putc,"%02u", alarm2_minute); if(input(PIN_B2) == 0) break; delay_ms(200); } lcd_gotoxy(21, 1); lcd_putc(" ALARM2 Hour: "); lcd_gotoxy(21, 2); lcd_putc(" "); delay_ms(200); while(TRUE){ ds1307_read(); ds1307_display(); if(input(PIN_B1) == 0) alarm2_hour++; if(alarm2_hour > 23) alarm2_hour = 0; lcd_gotoxy(30, 2); printf(lcd_putc,"%02u", alarm2_hour); if(input(PIN_B2) == 0) break; delay_ms(200); }} delay_ms(200); } if(input(PIN_B1) == 0){ output_low(PIN_B3); pwm_off(); } ds1307_read(); // Read data from DS1307 RTCC alarm_check(); // Check if there is an alarm ds1307_display(); // Diaplay time and calendar alarm_display(); // Display alarms delay_ms(50); } }