12864 Read and Write Program

If a problem occurs, it is usually not written strictly according to the sequence, especially in terms of delay.

Procedure: (Check the busy signal every time you read or write)

#define uchar unsigned char
#define uint unsigned int

#define Lcd_Bus P0 //MCU P2<------> LCM
sbit RS_12 = P3^5;
sbit RW_12 = P3^6;
sbit E_12 = P3^7;

void chk_busy(); //Check busy
void write_com(uchar cmdcode); //Write command address with row first and column last
void write_data(uchar Dispdata); // Write data
uchar read_data(void); //Read data The first byte needs to be read twice, that is, it needs to be read three times. The last two times are required. The first time, the address is automatically increased by 1, and the same is true for writing

void lcdreset(); //12864 initialization
void hzkdis(unsigned char code *s); //Display string
void Disp_Img(uchar code *img); //Drawing
void clrgdram(); //Clear the entire space
void clrscreen(); //Clear the screen, including the address

void ceshi() ; //First screen display

void chk_busy()
{ RS_12=0;
RW_12=1;
E_12=1;
Lcd_Bus=0xff;
while((Lcd_Bus&0x80)==0x80);
E_12=0;
}

void write_com(uchar cmdcode)
{
chk_busy();
RS_12=0;
RW_12=0;
E_12=1;
Lcd_Bus=cmdcode;
delay10(1);////////////////////Add appropriate delay when writing data
E_12=0;
delay10(1);;
}

void write_data(uchar Dispdata)
{
chk_busy();
RS_12=1;
RW_12=0;
E_12=1;
Lcd_Bus=Dispdata;
delay10(1); //Add appropriate delay when writing data
E_12=0;
delay10(1);
}

uchar read_data(void)
{
uchar da=0x00;
chk_busy();
Lcd_Bus=0xff;
RS_12=1;
RW_12=1;
E_12=1;
delay10(1);
da=Lcd_Bus;
E_12=0;
delay10(5);
return(da);
}

void lcdreset()
{ delayns(2);
write_com(0x30);
delay10(1); //Select basic instruction set
write_com(0x30); //Select 8-bit data stream
delay10(1);
write_com(0x0c); //Turn on display (no cursor, no inverting)
delay10(1);
write_com(0x01); //Clear display and set address pointer to 00H
delayns(1);
write_com(0x06); //Specify the cursor movement direction and display shift when reading and writing data
delayns(2);
}


void hzkdis(unsigned char code *s)
{ while(*s>0)
{ write_data(*s);
s++;
delay10(3);
}
}

void Disp_Img(uchar code *img)
{ unsigned int j=0;
unsigned char x,y,i;
for(i=0;i<9;i+=8)
for(y=0;y<32;y++)
for(x=0;x<8;x++)
{ write_com(0x36);//Function setting---8BIT control interface, expanded instruction set
write_com(y+0x80); //Row address
write_com(x+0x80+i); //Column address
write_com(0x30);
write_data(img[j++]);
write_data(img[j++]);
}

}

void clrgdram()
{ unsigned char x,y;
for(y=0;y<64;y++)
for(x=0;x<16;x++)
{ write_com(0x34);
write_com(y+0x80); // Row address
write_com(x+0x80); //Column address
write_com(0x30);
write_data(0x00);
write_data(0x00);
}
}

void clrscreen()
{
write_com(0x01);
delay10(3);
}

void ceshi()
{write_com(0x01); //Clear the display and set the address pointer to 00H
delay10(1);

write_com(0x80); //First line (if the address is: 80H, the first position of the first line of LCD will be displayed)
hzkdis(" Welcome ");

write_com(0x90); //The second line (if the address is: 90H, the first position of the second line of LCD is displayed)
hzkdis(" Here is group B 12 ");

write_com(0x88); //The third line (if the address is: 88H, that is, the first position of the second line of LCD is displayed)
hzkdis(" Constant Temperature Device Experiment ");

write_com(0x98); //The fourth line (if the address is: 98H, the first position of the second line of LCD will be displayed)
hzkdis(" Start now ");

}