Homemade 51 MCU common header files (st7920 serial mode)

ST7920.H

The user function is C51.
Copyright (c) 1988-2004 Keil Elektronik GmbH sum zhaojun
All rights reserved.
---------------------------- --------------------------------------------------*/
// Serial mode
#ifndef __ST7920_H__
#define __ST7920_H__

#define uint unsigned int
#define uchar unsigned char

//Pin definition
#define LCD_CS P3_2 // Chip select high level is valid. When using a single-chip LCD, the high level can be fixed.
#define LCD_SID P3_3 // Data
#define LCD_CLK P3_4 // Clock
#define LCD_PSB P3_5 // Low level indicates that it is driven by the serial port. The low level can be fixed.
#define LCD_RST P3_6 // LCD reset. The LCD module has its own reset circuit. It can be left unconnected.
//#define LCD_BACK P2_6 // LCD backlight control

/******************************************************** 
 Function name: void Delay_LCD(uint Number)
 Function: LCD delayDescription
 : If the BF flag is not checked before sending an instruction, a longer delay must be made between the previous instruction and this instructionEntry
 parameter: NumberReturn
 value: None 
 ****************************************************/
void Delay_LCD(uint Number) 
{
  uint i,j;

  for (i=0; i   {
      for(j=0; j<10; j++)
        {
   ;
  }
 }
}

/******************************************************** 
 Function name: void Send_byte(uchar Byte) 
 Function: Send a byte
 Input parameter: Byte
 Return value: None 
 ********************************************************/
void Send_byte(uchar Byte) 
{
 uchar i;

  for (i=0; i<8; i++)
    {
     LCD_SID = Byte&0x80; // Take out the highest bit and write serial data
     LCD_CLK = 1; // Serial synchronous clock signal
     LCD_CLK = 0;
    Byte <<= 1; // Shift left
   }  
}
/********************************************************* 
 Function name: void WriteCommandLCM()
 Function: Write command
 entry to LCMParameter: WCLCMReturn
 value: None  
 ****************************************************/
void WriteCommandLCM(uchar WCLCM)
{
   uchar Start_data,Hdata,Ldata;

 Start_data = 0xf8; // write instruction 11111000
  
   Hdata = WCLCM&0xf0; // take the upper four bits DDDD0000
   Ldata = (WCLCM << 4) & 0xf0; // take the lower four bits 0000DDDD

   Send_byte(Start_data); // Send the first byte of the start signal - format: 1111ABC
   Delay_LCD(5); // Delay is required

   Send_byte(Hdata); // Send the upper four bits of the second byte - format: DDDD0000
   Delay_LCD(1); // Delay is required

   Send_byte(Ldata); // Send the third byte of the lower four bits - format: 0000DDDD
   Delay_LCD(1); // Delay is required
}
/******************************************************** 
 Function name: void WriteDataLCM()
 Function: Write data to LCM1602Description
 : Write the data in the parameter WDLCM to LCMEntry
 parameter: WDLCMReturn 
 value: None  
 ****************************************************/
void WriteDataLCM(uchar WDLCM)
{
   uchar Start_data,Hdata,Ldata;

 Start_data = 0xfa; // write data 11111010 

   Hdata = WDLCM & 0xf0; // Take the upper four bits DDDD0000
   Ldata = (WDLCM << 4) & 0xf0; // Take the lower four bits 0000DDDD

   Send_byte(Start_data); // Send the first byte of the start signal - format: 1111ABC
   Delay_LCD(5); // Delay is required

   Send_byte(Hdata); // Send the upper four bits of the second byte - format: DDDD0000
   Delay_LCD(1); // Delay is required

   Send_byte(Ldata); // Send the lower four bits 3rd byte - format: 0000DDDD
   Delay_LCD(1); // Delay is required
}

/******************************************************** 
 Function name: void Lcdinit(void)
 Function: LCD initialization
 entry Parameter: NoneReturn
 value: None 
 ********************************************************/
void Lcdinit(void)  
{
   Delay_LCD(10); // Start waiting, wait for LCM to enter working status
   LCD_PSB = 0; // Serial port drive mode
   LCD_RST = 0;

 Delay_LCD(1); 
 LCD_RST = 1; // Reset LCD
   LCD_CS = 1; // Chip select

   WriteCommandLCM(0x30); // 8-bit interface, basic command set
   WriteCommandLCM(0x0c); // Display on, cursor off, reverse white off
   WriteCommandLCM(0x01); // Clear the screen, reset the DDRAM address counter to zero  
}

/******************************************************** 
 Function name: void DisplayListChar()
 Function: write string to the pointed address
 Entry parameter: x- horizontal coordinate, y- vertical coordinate, s- string
 Return value: None  
 ****************************************************/
void DisplayListChar(uchar x, uchar y, uchar code *s)
{
 uchar add; // display address

 switch (y) // Display address count
 {
  case 0: add = x + 0x80; break; // Address of the first line
  case 1: add = x + 0x90; break; // Address of the second line  
  case 2: add = x + 0x88; break; // Address of the third line
  case 3: add = x + 0x98; break; // Address of the fourth line
  default: break; 
 }

 WriteCommandLCM(0x30); // 8-bit interface, basic command set
 WriteCommandLCM(add); // write address

    while (*s > 0) // Write string
    {
     WriteDataLCM(*s);
        s++;
        Delay_LCD(50);
    }
}

/******************************************************** 
 Function name: void DisplayPicture(uint code *img)
 Function: Display graphics on LCDDescription
 : When displaying graphics on LCD, due to the particularity of ST7920, two screens should be usedControl 
 entry parameter: *imgReturn
 value: None 
 ********************************************************/
//Graphics modevoid
DisplayPicture(uint code *img) 
{ 
    uchar Line,Row; // Line is the row address; Row is the column addressuint
    regist = 0; // Graphics address register

 WriteCommandLCM(0x36); // Graphics mode, extended command
    // -------------- Upper half screen----------------
   for (Line=0; Line<32; Line++)     
    { 
       WriteCommandLCM(0x80 + Line); // Write row address
       WriteCommandLCM(0x80); // Write column

       for (Row=0; Row<16; Row++)
  {
       WriteDataLCM(img[regist++]); // Write image data
  }
    }
    // --------------- Lower half screen---------------
   regist=512; // Lower half screen starting data

   for (Line=0; Line<32; Line++)  
    { 
       WriteCommandLCM(0x80 + Line); // Write row address
    WriteCommandLCM(0x88); // Write column

       for (Row=0; Row<16; Row++)
  {
        WriteDataLCM(img[regist++]); // Write image data
  }
    }

 WriteCommandLCM(0x30); // Basic instructions
}

/******************************************************** 
 Function name: void main(void)
 Function: main function
 entry parameter: noneReturn
 value: none 
 ****************************************************/
void main(void)
{

   Lcdinit(); // Initialize LCD

   while(1)
   {

  DisplayListChar(0,0,"zhaojun");
   }

}

#endif