ZetoHkr

#include <reg51.h>

// define type abbreviation
#define uchar unsigned char
#define uint unsigned int
// define data port
#define DATAPORT P1

// define control pins
sbit halt = P2^7;
sbit fs1 = P2^6;
sbit md2 = P2^5;
sbit rst = P2^4;
sbit ce = P2^3;
sbit cd = P2^2;
sbit rd = P2^1;
sbit wr = P2^0;

// fonts
// method of obtaining: https://www.zhetao.com/fontarray.html
// parameter:
//     byte width: 8bit
//     font height: 16
//     columns: 2
//     font: Songti abc, size: 0 (automatic)
unsigned char code font[][16] = {
  /*--  0  --*/
  {0x00,0x00,0x00,0x18,0x24,0x42,0x42,0x42,0x42,0x42,0x42,0x42,0x24,0x18,0x00,0x00,},
  /*--  1  --*/
  {0x00,0x00,0x00,0x08,0x38,0x08,0x08,0x08,0x08,0x08,0x08,0x08,0x08,0x3E,0x00,0x00,},
  /*--  2  --*/
  {0x00,0x00,0x00,0x3C,0x42,0x42,0x42,0x02,0x04,0x08,0x10,0x20,0x42,0x7E,0x00,0x00,},
  /*--  3  --*/
  {0x00,0x00,0x00,0x3C,0x42,0x42,0x02,0x04,0x18,0x04,0x02,0x42,0x42,0x3C,0x00,0x00,},
  /*--  4  --*/
  {0x00,0x00,0x00,0x04,0x0C,0x0C,0x14,0x24,0x24,0x44,0x7F,0x04,0x04,0x1F,0x00,0x00,},
  /*--  5  --*/
  {0x00,0x00,0x00,0x7E,0x40,0x40,0x40,0x78,0x44,0x02,0x02,0x42,0x44,0x38,0x00,0x00,},
  /*--  6  --*/
  {0x00,0x00,0x00,0x18,0x24,0x40,0x40,0x5C,0x62,0x42,0x42,0x42,0x22,0x1C,0x00,0x00,},
  /*--  7  --*/
  {0x00,0x00,0x00,0x7E,0x42,0x04,0x04,0x08,0x08,0x10,0x10,0x10,0x10,0x10,0x00,0x00,},
  /*--  8  --*/
  {0x00,0x00,0x00,0x3C,0x42,0x42,0x42,0x24,0x18,0x24,0x42,0x42,0x42,0x3C,0x00,0x00,},
  /*--  9  --*/
  {0x00,0x00,0x00,0x38,0x44,0x42,0x42,0x42,0x46,0x3A,0x02,0x02,0x24,0x18,0x00,0x00,},
  /*--  space  --*/
  {0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,},
};

// delay function
void delay_lcd(uchar t) {
  for (; t != 0; t--);
}

// write data to lcd display
void write_data(uchar dat) {
  // The D of the C/D pin is available at low level, so CD = 0;
  cd = 0;
  // CE (Chip Enable) pin is available at low level, so CE = 0;
  ce = 0;
  // WR (Write) pin is available at low level, so WR = 0;
  wr = 0;
  // Send the data of dat to the data port;
  DATAPORT = dat;
  delay_lcd(1);
  // end write.
  wr = 1; ce = 1;
}

// write command to lcd display
void write_cmd(uchar cmd) {
  // The C of the C/D pin is available at high level, so CD = 1;
  cd = 1;
  // CE (Chip Enable) pin is available at low level, so CE = 0;
  ce = 0;
  // WR (Write) pin is available at low level, so WR = 0;
  wr = 0;
  // Send the command data of cmd to the data port;
  DATAPORT = cmd;
  delay_lcd(1);
  // end write.
  wr = 1; ce = 1;
}

// show half-width characters
// x: line position
// y: column position
// flag: whether to display in reverse color
// ch: font index pointer (array)
// count: number of characters
void display_hw(uchar x, uchar y, int flag, uchar ch, int count) {
  unsigned int place, i = 0, k;
  // iterate over character array
  for (i = 0; i < count; i++) {
    // One character 8bit width, one line 240bit, 30 characters in total
    // y: the vertical offset
    place = x * 30 + y;
    // half-width character contains 16 rows of 8-bit dot matrix
    for (k = 0; k <= 15; k++) {
      // write high address
      write_data(place & 0xff);
      // write low address
      write_data(place >> 8);
      // set address
      write_cmd(0x24);
      // Set continuous read and write
      write_cmd(0xb0);
      // Find the dot matrix data of the corresponding character in the font array according to the element index of ch
      write_data(flag ? font[ch[i]][k] : ~font[ch[i]][k]);
      place += 30;
    }
    // A line with more than 30 characters needs to be wrapped
    if (y > 30) {
      // One character 16bit height
      x += 16;
      y = 0;
    } else {
      // Continue write
      y += 2;
    }
  }
}

// initial lcd display
void lcd_initial() {
  // When FS1 is at low level, the font is 8*8, So fs1 = 0;
  fs1 = 0;
  // set graphics area
  write_data(30);
  write_data(0);
  write_cmd(0x43);
  // Turn off text display, turn on graphic display
  write_cmd(0x98);
}

void main(void) {
  unsigned char c[1] = {1};
  lcd_init();
  while (1) {
    display_hw(16, 0, 1, c, 1);
  }
}