C51 driver for 1602LCD module

I have a 1602 LCD, ks0066 driver chip, with LED backlight. I wrote a driver with reference to some information on the website. After writing it, I found that it is basically the same as the code circulating on the Internet.

/*========================================

                          1602lcd module driver

==========================================

Description: 1. Crystal: 11.0592MHz

      2.1602 driver: ks0066

******************************************/

#include

#include

#define lcm_rs P2_7 //Register selection

#define lcm_rw P2_6 //Read/write control

#define lcm_e P2_5 //Read/write enable

#define lcm_blk P2_4 //backlight led 1.off 0.on

#define lcm_data P0

// Function declaration

void delay5ms(void);

void delay400ms(void);

void lcm_write_command(unsigned char wc_lcm,busy_c);

/**********************************

//Function name: void lcm_ini(void)

// Pass parameters: None

//Return value: None

//Function: LCM initialization

//Function description:

*************************************/

void lcm_ini(void)

{

     lcm_data = 0;

     lcm_write_command(0x38,0); //16*2 display, 5*7 dot matrix, 8-bit data interface, no busy detection

     delay5ms();

     lcm_write_command(0x38,0);

     delay5ms();

     lcm_write_command(0x38,0); //Three-time display mode, no busy detection

     delay5ms();

     lcm_write_command(0x38,1); //16*2 display, 5*7 dot matrix, 8-bit data interface, need to detect busy

     lcm_write_command(0x80,1); //Turn off the display

     lcm_write_command(0x01,1); //clear display    

     lcm_write_command(0x06,1); //Pointer and cursor +1, no scrolling

     lcm_write_command(0x0c,1); //Turn on display, don't display cursor

}

/**********************************

//Function name: unsigned char lcm_read_status(void)

// Pass parameters: None

//Return value: unsigned char

//Function: Read lcm status, wait for lcm to be idle

//Function description: DB7=1, busy

*************************************/

unsigned char lcm_read_status(void)

{

     lcm_data=0xff;

     lcm_rs=0;

     lcm_rw=1;

     lcm_e=0;

     lcm_e=0;

     lcm_e=1;

     while(lcm_data & 0x80);

     return lcm_data;

}

/**********************************

//Function name: void lcm_write_data(unsigned char wd_lcm)

// Pass parameter: unsigned char wd_lcm

//Return value: None

//Function: lcm write data

//Function description:    

*************************************/

void lcm_write_data(unsigned char wd_lcm)

{

     lcm_read_status(); //Judge the lcm busy flag

     lcm_data = wd_lcm;

     lcm_rs = 1;

     lcm_rw = 0;

     lcm_e = 0;

     lcm_e = 0;

     lcm_e = 1;

}

/**********************************

//Function name: void lcm_write_command(unsigned char wc_lcm, busy_c)

// Pass parameters: unsigned char wc_lcm, busy_c

//Return value: None

//Function: lcm write command

//Function description: busy_c=0, no need to detect busy signal

*************************************/

void lcm_write_command(unsigned char wc_lcm, busy_c)

{

     if (busy_c)

         lcm_read_status();

     lcm_data = wc_lcm;

     lcm_rs=0;

     lcm_rw = 0;

     lcm_e = 0;

     lcm_e = 0;

     lcm_e = 1;

}

/**********************************

//Function name: void disp_one_char(unsigned char x, unsigned char y, unsigned char disp_data)

// Pass parameters: unsigned char x, unsigned char y, unsigned char disp_data

//Return value: None

//Function: Display a character at the specified position

//Function description:    

*************************************/

void disp_one_char(unsigned char x, unsigned char y, unsigned disp_data)

{

     y = y&0x01;

     x = x&0x0f; //Limit to 2 lines, 15 characters per line

     if (y)

         x =x + 0x40; //Calculate RAM address

     x = x + 0x80;

     lcm_write_command(x,0);

     lcm_write_data(disp_data);

}

/**********************************

//Function name: void disp_one_char(unsigned char x, unsigned char y, unsigned char *disp_data)

// Pass parameters: unsigned char x, unsigned char y, unsigned char *disp_data

//Return value: None

//Function: Display a string of characters at the specified position

//Function description:    

*************************************/    

void disp_list_char(unsigned char x, unsigned char y, unsigned char *disp_data)    

{

     unsigned char char_length,j;

     char_length = strlen(disp_data);

     y = y&0x1;

     x = x&0x0f;

     for (j=0;j

     {

         disp_one_char( x,y,disp_data[j]); //Display a character

         x++;

     }

}

/**********************************

//Function name: void delay5ms(void)

// Pass parameters: None

//Return value: None

//Function: Delay 5MS

//Function description:

*************************************/

void delay5ms(void)

{

     unsigned int TempCyc = 5552;

     while(TempCyc--);

}

/**********************************

//Function name: void delay400ms(void)

// Pass parameters: None

//Return value: None

//Function: L delay 400MS

//Function description: LCM power-on delay

*************************************/

void delay400ms(void)

{

     unsigned char TempCycA = 5;

     unsigned int TempCycB;

     while(TempCycA--)

     {

         TempCycB=7269;

         while(TempCycB--);

     };

}

/*****d******************************

//Function name: void main(void)

// Pass parameters: None

//Return value: None

//Function: main function

//Function description:    

************************************/

void main(void)

{

     delay400ms();

     lcm_ini();

                 disp_list_char(1,0,"Welcome");

                 disp_list_char(1,0,"www.dzkjcn.com")

                 while(1);

}

The above program simply displays two lines of characters without scrolling or backlight.

C51 program for 4-line LCD 1602

----------------------------------

| LCM-----51 | LCM-----51 |　

----------------------------------

|RS-----P2.1 | DB4-----P1.4 |

|RW-----P2.0 | DB5-----P1.5 |

|E-----P2.2 | DB6-----P1.6 |

|VLCD connects 1K resistor to GND| DB7-----P1.7 |

-------------------------------------------------- -

[Note: AT89S51 uses 12M crystal oscillator]

================================================== ===========*/

void writelcd(bit command,unsigned char ddata)

{

ReadStatusLCM(); //Detection busy

LCM_Data = (ddata&0xf0)|(P1&0x0f);

LCM_RW = 0;

if(command==0) LCM_RS = 0; else LCM_RS=1;

LCM_E = 1;

LCM_E = 0;

LCM_E = 0;

LCM_Data = ((ddata<<4)&0xf0)|(P1&0x0f);

if(command==0) LCM_RS = 0; else LCM_RS=1;

LCM_E = 1;

LCM_E = 0;

LCM_E = 0;

}

//Read status

unsigned char ReadStatusLCM(void)

{

P1_7=1;

LCM_RS = 0;

LCM_RW = 1;

LCM_E = 0;

LCM_E = 0;

LCM_E = 1;

while(P1_7&0x01);//Detect busy signal

return(P1_7);

}

void LCMInit(void) //LCM initialization

{

LCM_Data=0xff;

writelcd(0,0x28); //Three-time display mode setting, do not detect busy signal

Delay5Ms();

writelcd(0,0x28);

Delay5Ms();

writelcd(0,0x28);

Delay5Ms();

writelcd(0,0x28); //Display mode setting, start to require each busy signal detection

writelcd(0,0x0c); //Display on and cursor setting

writelcd(0,0x01); //display clear screen

writelcd(0,0x06); //Display cursor movement settings

}

//Display a character at the specified position

void DisplayOneChar(unsigned char X, unsigned char Y, unsigned char DData)

{

Y &= 0x1; X &= 0xF; //Limit X to not be greater than 15, Y to not be greater than 1

if (Y) X |= 0x40; //When the second line is to be displayed, the address code + 0x40;

X |= 0x80; //Calculate the instruction code

writelcd(0,X);

writelcd(1,DData);

}

//Display a string of characters at the specified position ***Original characters will not be displayed if they encounter a space 0x20***

void DisplayListChar(unsigned char X, unsigned char Y, unsigned char code *DData)

{

   unsigned char ListLength,j;

   ListLength = strlen(DData);

   Y &= 0x1;

   X &= 0xF; //Limit X to not be greater than 15, Y to not be greater than 1

       if (X <= 0xF) //X coordinate should be less than 0xF

         {

       for(j=0;j

         {

              DisplayOneChar(X, Y, DData[j]); //Display a single character

              X++;

             }

         }

}

//5ms delay

void Delay5Ms(void)

{

unsigned int TempCyc = 5552;

while(TempCyc--);

}

//400ms delay

void Delay400Ms(void)

{

unsigned char TempCycA = 5;

unsigned int TempCycB;

while(TempCycA--)

{

   TempCycB=7269;

   while(TempCycB--);

};

}

/////LCM_end///////