Program for LCD1602 to display adjustable clock

//Hope it helps beginners//

#include
#define uchar unsigned char
#define uint unsigned int
sbit lcden=P2^7;
sbit lcdrs=P2^6;
sbit W=P2^5;
sbit k1=P3^0;
sbit k2=P3^1;
sbit k3=P3^2;
uchar num,count,k1num;
char miao,fen,shi;
uchar code table[]=" 2015-01-5 SAT" ;
uchar code table1[]=" 00:00:00";

void delay(uint z)
{
uint x,y;
for(x=z;x>0;x--)
for(y=110;y>0;y--);
}

void write_com(uchar com) // write command
{
W=0;
lcdrs=0; //RS selects write command or write data, write command
P0=com; //send the written command to the data bus
delay(5); //delay a little to wait for the data to stabilize
lcden=1; //enable the end to give a high pulse, because the initialization function has set lcden to 0
delay(5); //delay a little
lcden=0; //set the enable end to 0 to complete the high pulse
}

void write_data(uchar date)
{
lcdrs=1;
P0=date;
delay(5);
lcden=1;
delay(5);
lcden=0;
}

void write_sfm(uchar add,uchar date) //Write data to a certain address
{
uchar shi,ge;
shi=date/10;
ge=date;
write_com(0x80+0x40+add); //The address pointer points to the add+1th in the second row
write_data(0x30+shi); //Send data, send the tens digit of data
write_data(0x30+ge); //Send data, send the ones digit of data
}

void keyscan()
{
if(k1==0)
{
delay(5);
if(k1==0)//debounce
{
k1num++; //Count, calculate how many times k1 is pressed
while(!k1); //Release detection
if(k1num==1) //When pressed once
{
TR0=0; //Timer stops, time stops
write_com(0x0f); //Turn on display, display cursor, cursor flashes
write_com(0x80+0x49); //The data pointer points to the units of seconds in the second line
}

if(k1num==2) //When k1 is pressed twice
{

// write_com(0x0f);
write_com(0x80+0x46); //The data pointer points to the units of minutes in the second line

}
if(k1num==3) //When k1 is pressed three times
{
// write_com(0x0f);
write_com(0x80+0x43); //The data pointer points to the unit digit of the second line
}

if(k1num==4) //If it is pressed four times
{
TR0=1; //Start timerk1num
=0; //
Clearwrite_com(0x0c); //Close cursor
}
// if(k1num==5)
// {
// write_com(0x80+0x14)
// }
}
}
if(k1num!=0) //If k1 has been pressed
{
if(k2==0) //If k2 is pressed
{
delay(5);
if(k2==0)
{
while(!k2); //Release detectionif
(k1num==1) //When k1 is pressed once, adjust the seconds
{
miao++; //Add one second each time k2 is pressedif
(miao==60)
{
miao=0;
}
write_sfm(8,miao); //Data is displayed in the 9th and 10th positions of the second line
write_com(0x80+0x40+9); //Cursor has been set in k1, data pointer points to 0x48

}
if(k1num==2) //If k1 is pressed twice
{
fen++;
if(fen==60)
fen=0;
write_sfm(5,fen); //Data is sent to the sixth position++
write_com(0x80+0x40+6); //Data pointer points to the seventh position } if(k1num==3) //If k1 is pressed 3 times { shi++; if(shi==24) shi=0; write_sfm(2,shi); //Data is sent to the third position++ write_com(0x80+0x40+3); //Address pointer points to the fourth position } } } if(k3==0) //After k1 is pressed, if k3 is pressed { delay(5); if(k3==0) { while(!k3); if(k1num==1) //If k1 is pressed once { miao--; if(miao==-1) { miao=59; } write_sfm(8,miao); //Data is sent to the ninth position of the second line++ write_com(0x80+0x40+9); //The pointer points to the tenth position } if(k1num==2) { fen--; if(fen==-1) fen=59; write_sfm(5,fen); write_com(0x80+0x40+6); } if(k1num==3) { shi--; if(shi==-1) shi=23; write_sfm(2,shi); write_com(0x80+0x40+3); } } } } }

void init() //initialization function
{
// dula=0;
// wela=0;
lcden=0;
write_com(0x38); //Set 16*2 display, 5*7 dot matrix, 8-bit data interface
write_com(0x0c ); //Open display, do not display cursor
write_com(0x06); //When writing a data, the address pointer increases by 1, and the cursor increases by 1. When displaying a data, the whole screen does not move
write_com(0x01); //Data pointer clears to 0, display clears to 0
write_com(0x80); //Display on the screen
TMOD=0x01;
TH0=(655536-50000)/256;
TL0=(655536-50000)%6;
EA=1;
ET0=1;
TR0=1;
}

void main()
{
init(); //初始化
for(num=0;num<15;num++)
{
write_data(table[num]);
delay(10);
}

write_com(0x80+0x40); //The second line is displayed at the beginning
for(num=0;num<10;num++)
{
write_data(table1[num]);
delay(5);
}
while(1)
{
keyscan();

}
}

void timer0() interrupt 1
{
TH0=(655536-50000)/256;
TL0=(655536-50000)%6;
count++;
if(count==18) //一秒时间到
{
count=0;
miao++;
if(miao==60)
{ miao=0;
fen++;
if(fen==60)
{
fen=0;
shi++;
if(shi==24)
{
shi=0;
}
write_sfm(2,shi);
}
write_sfm(5,fen);
}
write_sfm(8,miao);
}
}