LCD12864 LCD display program

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

Engineering: 3-wire serial drive mode of 12864 LCD driven by ST7920

Pin definition: RS(CS)=====> PD3 //PB0

    RW(SID)====> PD4     //PB1

          EN(SCLK)===> PD6// PB2

    PSB is hardware controlled. A high level is for 8-bit or 4-bit parallel mode, and a low level is for serial mode.

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

#include

#include

#define uchar unsigned char

#define uint unsigned int 

#define nop()  NOP()

#define xtal 8

#define Set_CS() DDRD |= (1<<3);PORTD |= (1<<3)

#define Set_SID() DDRD |= (1<<4);PORTD |= (1<<4)

#define Set_SCLK() DDRD |= (1<<6);PORTD |= (1<<6)

#define Clr_CS() DDRD |= (1<<3);PORTD &=~(1<<3)

#define Clr_SID() DDRD |= (1<<4);PORTD &=~(1<<4)

#define Clr_SCLK() DDRD |= (1<<6);PORTD &=~(1<<6)

//====================================================================

// Function declaration

void Delay(uint ms); //Delay subroutine

void W_1byte(volat RW, volat RS, volat W_data);

void Write_8bits(uint W_bits);

void LCD_Init(void);

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

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

//===================================================================

const uchar mynew1[]={"Welcome to my home"};

const uchar mynew2[]={"Create by:LQG  "};

const uchar mynew3[]={"There are many friends in the world"};

const uchar mynew4[]={"The world is so small"};

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

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

void main()

{ fly i = 0;

DDRD &= ~BIT(7);

PORTD &= ~BIT(7);

DDRC |=BIT(6);

PORTC &= ~BIT(6);

DDRC &= ~BIT(7);

PORTC &= ~BIT(7);

Clr_CS();

Clr_SID();

Clr_SCLK();

LCD_Init();

while(1)

{ 

  nop();

  nop();

  W_1byte(0,0,0x80); //Displayed address 0x80

  nop();

  for(i=0;mynew1[ i]!='';i++)

  {

   W_1byte(0,1,mynew1);

  }

  W_1byte(0,0,0x90); //Displayed address 0x90

  for(i=0;mynew2!='';i++)

  {

   W_1byte(0,1,mynew2); 

  }

  W_1byte(0,0,0x88); //Displayed address 0x88

  for(i=0;mynew3!='';i++)

  {

   W_1byte(0,1,mynew3);

  }

  W_1byte(0,0,0x98+3); //The displayed address 0x98 +3 is a space and starts with three characters, otherwise it will be garbled.

  for(i=0;mynew4!='';i++)

  {

   W_1byte(0,1,mynew4);

  }

  nop();

  for(;;)

  {

    continue;

  } 

}

}

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

void LCD_Init(void)

{

  fly cmd;

  cmd=0x30; //Function setting 8-bit data, basic instructions

W_1byte(0,0,cmd);

Delay(2);

cmd=0x0C; //Display status ON, cursor OFF, highlight OFF

W_1byte(0,0,cmd); //write command

Delay(2);

cmd=0x01; //Clear display

W_1byte(0,0,cmd); //write command

Delay(2);

cmd=0x02; //Address return

W_1byte(0,0,cmd); //write command

Delay(2);

cmd=0x80; //Set DDRAM address

W_1byte(0,0,cmd); //write command

Delay(2); //Delay

}

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

Function name: W_1byte

Entry parameters: RW, RS, W_data

Export parameters: None

Date of establishment: March 3, 2007

Modified Date:

Function: Write one byte of data to the 12864 LCD, including instructions and data

Description: RW=1, read data from LCD to MCU; RW=0, write data to LCD;

   (Generally, RW is set to 0, which means that data is only written to the LCD, not read)

          RS=1, data is written; RS=0, instructions are written;

    Normal mode: RW=0, RS=1; write data

       RW=0, RS=0; write instruction

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

void W_1byte(float RW, float RS, float W_data)

{

uint H_data,L_data,S_ID = 0xf8;  //11111RWRS0

if(RW == 0)

{

   S_ID &=~ 0x04;

}

else     //if(RW==1)

{

   S_ID |= 0X04;

}

if(RS == 0)

{

   S_ID &=~ 0x02;

}

else     //if(RS==1)

{

   S_ID |= 0X02;

}

H_data = W_data;

H_data &= 0xf0; //Shield the lower 4 bits of data

L_data = W_data; //xxxx0000 format

L_data &= 0x0f; //Shield the high 4 bits of data

L_data <<= 4; //xxxx0000 format

Set_CS();

Write_8bits(S_ID); //Send S_ID

Write_8bits(H_data); //Send H_data

Write_8bits(L_data); //Send L_data

Clr_CS(); 

}

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

Function name: Write_8bits

Input parameter: W_bits

Export parameters: None

Date of establishment: March 3, 2007

Modified Date:

Function: responsible for serial output of 8 bits

illustrate:

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

void Write_8bits(uint W_bits)

{

uint i,Temp_data;

for(i=0; i<8; i++)

{

  Temp_data = W_bits;

  Temp_data <<= i;

  if((Temp_data&0x80)==0)  //bit7 is zero

  {

   Clr_SID();

   nop();

   Set_SCLK();

   nop();

   nop();

   Clr_SCLK();

   nop();

   Clr_SID();

  }

  else         //bit7 is one

  {

   Set_SID();

   nop();

   Set_SCLK();

   nop();

   nop();

   Clr_SCLK();

   nop();

   Clr_SID();

  } 

}

}

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

Function name: Delay

Entry parameter: ms

Export parameters: None

Date of establishment: March 3, 2007

Modified Date:

Function: millisecond delay program, when the crystal oscillator is 1Mhz, xtal=1;

illustrate:

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

void Delay(uint ms) 

{ 

    uint i; 

    while(ms--)    

   { 

     for(i=1;i<(uint)(xtal*143-2);i++) 

         ; 

   }   

}

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