while(RB1)
    {
        lcd_goto(0x41);
        showtemp();
        __delay_ms(50);
        if(command == 0x36) { i = ReadHour()+1; if(i>23) i = 0; SetHour(i); SetSeconds(0); command = 255; }
        if(command == 0x32) { i = ReadMin()+1; if(i>59) i = 0; SetMin(i); SetSeconds(0); command = 255;  }
        showtime();
        __delay_ms(50);
    }

#include <htc.h>

#define _XTAL_FREQ 4000000



#define SCL1 TRISB3
#define SDA1 TRISB4
#define SCL1_IN RB3
#define SDA1_IN RB4

void i2c_delay (void);


void i2c_start(void);

void i2c_stop (void);

bit i2c_tx(unsigned char d);

unsigned char i2c_rx(unsigned char ack);
unsigned char BCDconv (unsigned char source);
unsigned char DCBconv (unsigned char source);
void SetMin(unsigned char minutes);
unsigned char ReadMin();
void SetHour(unsigned char hours);
unsigned char ReadHour();
void SetSeconds(unsigned char seconds);
unsigned char ReadSeconds();

#include <htc.h>
#include "softi2c.h"

void i2c_delay (void) //Задержка speed/18
{
__delay_us(5);
}

void i2c_start(void)  //Старт передачи
{
SCL1 = 1;
SDA1 = 1;
i2c_delay();
SDA1 = 0;
i2c_delay();
SCL1 = 0;
}

void i2c_stop (void)
{
i2c_delay();
SDA1 = 0;
SCL1 = 0;
i2c_delay();
SCL1 = 1;
i2c_delay();
SDA1 = 1;

}

bit i2c_tx(unsigned char d)
{
char x;
static bit b;
   for (x=0; x<8; x++) {
       i2c_delay();
       if (d&0x80) SDA1 = 1;
       else SDA1 = 0;
       i2c_delay();
       SCL1 = 1;
       d <<= 1;
       i2c_delay();
       SCL1 = 0;
   }
i2c_delay();
i2c_delay();
SDA1 = 1;
SCL1 = 1;
i2c_delay();

b = SDA1_IN;
SCL1 = 0;
return b;

}

unsigned char i2c_rx(unsigned char ack)
{
unsigned char x,d=0;
    SDA1 = 1;
    for (x=0; x<8;x++) {
                        d <<= 1;
                               do {
                                   i2c_delay();
                                   SCL1 = 1;
                                   } while (SCL1_IN==0);
                        i2c_delay();
                        if (SDA1_IN) d |= 1;
                        SCL1 = 0;
    }
    i2c_delay();
    if (ack) SDA1 = 0;
                   else SDA1 = 1;
    SCL1 = 1;
    i2c_delay();
    SCL1 = 0;
   
    return d; 

}


unsigned char BCDconv (unsigned char source) {
  unsigned char temp_min=0;
  unsigned char temp_maj=0;
   temp_min = source&15;
   temp_maj = source >> 4;
   //printf("\r\n minor - %x", temp_min);
   //printf("\r\n major - %x", temp_maj);
   temp_maj *= 10;
   //printf("\r\n major - %x", temp_maj);
 
   return temp_maj+temp_min;
}

unsigned char DCBconv (unsigned char source) {
 unsigned char temp_min=0;
 unsigned char temp_maj=0;
 temp_maj = source/10 ;
 temp_min = source - temp_maj*10;
 temp_maj <<= 4;

 return temp_maj+temp_min;

}

void SetMin(unsigned char minutes) {        //записываем значение в минуты
     i2c_start();           
    i2c_tx(0b11010000);
    i2c_tx(0x01);
    i2c_tx(DCBconv(minutes));
    i2c_stop();
}

unsigned char ReadMin() {
    unsigned char clockreturn1 = 0;
    i2c_start();            //читаем значение минут
    i2c_tx(0b11010000);
    i2c_tx(0x01);
    i2c_start();
    i2c_tx(0b11010001);
    clockreturn1 = i2c_rx(0);
    i2c_stop();

    return BCDconv(clockreturn1);
}

void SetHour(unsigned char hours) {        //записываем значение в часы
     i2c_start();           
    i2c_tx(0b11010000);
    i2c_tx(0x02);
    i2c_tx(DCBconv(hours));
    i2c_stop();
}

unsigned char ReadHour() {
    unsigned char clockreturn2 = 0;
    unsigned char clockreturn22 = 0;
    i2c_start();            //читаем значение часов
    i2c_tx(0b11010000);
    i2c_tx(0x02);
    i2c_start();
    i2c_tx(0b11010001);
    clockreturn2 = i2c_rx(0);
    i2c_stop();
    /*
    temp2 = temp&0b00001111;
    temp /= 10;
    temp = temp >> 4;
    temp = temp*10 + temp2;*/
   
    return BCDconv(clockreturn2);
}

void SetSeconds(unsigned char seconds) {        //записываем значение в секунды
    i2c_start();           
    i2c_tx(0b11010000);
    i2c_tx(0x00);
    i2c_tx(DCBconv(seconds) & 0b01111111);
    i2c_stop();
}

unsigned char ReadSeconds() {
    unsigned char clockreturn = 0;
    i2c_start();            //читаем значение минут
    i2c_tx(0b11010000);
    i2c_tx(0x00);
    i2c_start();
    i2c_tx(0b11010001);
    clockreturn = i2c_rx(0);
    i2c_stop();

    return BCDconv(clockreturn);
}

    i = ReadSeconds();
    if(i>60) i = 0;
    SetSeconds(i & 0b01111111);
    i = 0;

void showtime(void)
{
    unsigned char sec;
    unsigned char min;
    unsigned char hur;
    lcd_goto(0);
    hur = ReadHour();
    lcd_showno2(hur);
    lcd_putch(':');
    lcd_showno2(min);
    min = ReadMin();
    lcd_putch(':');
    sec = ReadSeconds();
    lcd_showno2(sec);
}

void lcd_showno2(unsigned char var)
{
    if((var/10)>0)
    {
        unsigned char tmp = var;
        lcd_putch(0x30 + (var/10));
        while(tmp>=10) tmp = tmp-10;
        lcd_putch(0x30 + tmp);
       
    }
    else
    {
        lcd_putch(0x30);
        lcd_putch(0x30 + var);
    }
}