Create library for PCF8583 (RTC) and enable it

main.c

@@ -1,13 +1,18 @@
 #include <avr/io.h>
 #include <avr/interrupt.h>
+#include <util/delay.h>
 #include "i2c.h"
+#include "rtc.h"
 #include "led.h"
 
 #define I2C_BITRATE 100000UL // 100kHz
+#define RTC_I2C_ADDR 0xA2
+
 
 int main() 
 {
   i2c_init(I2C_BITRATE); 
+  rtc_int0_init();
   led_init();
 
   sei();
@@ -20,4 +25,12 @@ int main()
   {
 
   }
+}
+
+ISR(INT0_vect)
+{
+  struct time curr_time = rtc_read_time(RTC_I2C_ADDR);
+  led_hour = curr_time.hour;
+  led_minute = curr_time.minute;
+  led_second = curr_time.second;
 }

rtc.c

@@ -0,0 +1,37 @@
+#include <avr/io.h>
+#include "rtc.h"
+#include "i2c.h"
+
+void rtc_int0_init(void)
+{
+  INT0_DIR &= ~(1<<INT0_PIN);
+  INT0_PORT |= (1<<INT0_PIN);
+  GICR |= (1<<INT0);
+}
+
+void rtc_int1_init(void)
+{
+  INT1_DIR &= ~(1<<INT1_PIN);
+  INT1_PORT |= (1<<INT1_PIN);
+  GICR |= (1<<INT1);
+}
+
+void rtc_set_time(uint8_t part, uint8_t value) 
+{  
+  uint8_t bcd = DEC_2_BCD(value);
+  i2c_writebuf(RTC_I2C_ADDR, part, 1, &bcd);
+}
+
+struct time rtc_read_time(void) 
+{
+  uint8_t buffer[3];
+  i2c_readbuf(RTC_I2C_ADDR, 0x02, 3, buffer);
+
+  struct time curr_time = {
+    BCD_2_DEC(buffer[2]),
+    BCD_2_DEC(buffer[1]),
+    BCD_2_DEC(buffer[0])
+  };
+
+  return curr_time;
+}

rtc.h

@@ -0,0 +1,33 @@
+#ifndef __RTC_H__
+#define __RTC_H__
+
+#define RTC_I2C_ADDR 0xA2
+
+#define SECOND 0x02
+#define MINUTE 0x03
+#define HOUR 0x04
+
+#define INT0_PORT PORTD
+#define INT0_DIR DDRD
+#define INT0_PIN PD2
+#define INT1_PORT PORTD
+#define INT1_DIR DDRD
+#define INT1_PIN PD3
+
+
+#define DEC_2_BCD(dec) ((((dec) / 10) << 4) | ((dec) % 10))
+#define BCD_2_DEC(bcd) (((((bcd) >> 4) & 0x0F) * 10) + ((bcd) & 0x0F))
+
+struct time 
+{
+  uint8_t hour;
+  uint8_t minute;
+  uint8_t second;
+};
+
+void rtc_int0_init(void);
+void rtc_int1_init(void);
+void rtc_set_time(uint8_t part, uint8_t value);
+struct time rtc_read_time(void);
+
+#endif