[51 microcontroller] 1602 custom character principles and examples (examples of "Chinese", love and degrees Celsius)

principle

When setting the contrast of the 1602 screen, we can see a 5*8 dot matrix. In fact, the LCD displays the character fonts (picture below), and the CGROM has been defined and can only be read but not written, while the RAM It can be read and written, so we just need to write our custom character font into the corresponding CGRAM. CGRAM has a total of 8 corresponding addresses: (0x40, 0x48, 0x50, 0x58, 0x60, 0x68, 0x70, 0x78 ), because each font corresponds to 8 lines, so you need to add 8 after each font is written. When writing to CGRAM according to the instructions, you need to add 0x40, so the corresponding address is as above. However, in fact, the actual address of CGRAM is 0x00-0x07, so write it after When entering data, you need to write it according to the actual address. The same principle applies to the fonts in CGROM.

Font code: 1602 display mode is 5*7 dot matrix. The font code corresponds to the 8 lines of the font graphic. The first three digits of each line are 0 and the last line is 0x00. Therefore, the character code for degrees Celsius is: 0x10, 0x06, 0x09,0x08,0x08,0x09,0x06,0x00

The font code can be obtained using ZIMO221 font extraction software.                      

Sample code

#include

#include   //strlen header file

//Define custom symbols for different digit variable types

#define uint8 unsigned char

#define uint16 unsigned short int

#define uint32 unsigned long int

#define int8 signed char

#define int16 signed short int

#define int32 signed long int

#define uint64 unsigned long long int

#define int64 signed long long int

//Define some commonly used instructions in 1602 so that different readers can modify them according to their own needs

#define SETMODE 0x38 //16*2 display, 5*7 dot matrix, 8-bit data interface

#define DISOPEN 0x0C //Display on, do not display the cursor, the cursor does not flash

#define DISMODE 0x06 //Add 1 to the address after reading and writing characters, and the screen display will not move

#define SETADDR 0x80 //Set the initial value of the data address pointer

#define CLEAR 0x01 //Clear the screen and clear the data pointer to zero

#define RET 0x02 //Enter, clear data pointer 

#define PORT P0 //I/O port 

sbit RS = P3^5;

sbit E = P3^4; 

sbit dula = P2^6;

sbit wela = P2^7;

void delay(uint16 time);

void Write1602_Com(uint8 com);

void Write1602_Dat(uint8 dat);

void Init1602(void);

void Write1602_Str(uint8 addr,uint8 length,uint8 *pbuf);

uint8 code xin[8]={ //Xin character model

0x00,0x1B,0x1F,0x1F,0x1F,0x0E,0x04,0x00

};

uint8 code hot[8]={ //Celsius temperature font

0x10,0x06,0x09,0x08,0x08,0x09,0x06,0x00

};

uint8 code zuo[8]={ //Chinese left part font model

0x00,0x02,0x01,0x02,0x01,0x01,0x02,0x00

};

uint8 code you[8]={ //Chinese right part font model

0x00,0x1e,0x12,0x0c,0x0a,0x11,0x00,0x00             

};

uint8 i; 

void main()

{

    Init1602(); //Initialize 1602 

    //Customized CGRAM

    Write1602_Str(0x40,8,hot); //Celsius temperature scale->in memory 000 of CGRAM

    Write1602_Str(0x48,8,zuo); //The left part of Han -> CGRAM memory 001

    Write1602_Str(0x50,8,you); //The right part of Han -> CGRAM memory 010

    Write1602_Str(0x58,8,xin); //Heart->Memory 011 of CGRAM

    Write1602_Com(0x80); //Set the DDRAM address, which is the displayed position

    for(i=0;i<8;i++)

       Write1602_Dat(0);

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

       Write1602_Dat(3);

    Write1602_Com(0xc0); //Same as above

    for(i=0;i<16;i++)

       Write1602_Dat(1+i%2);

    while(1);

} 

void delay(uint16 time)

{

    uint8 i,j;

for(i=time;i>0;i--)

for(j=0;j<110;j++);

} 

void Init1602(void)

{

dula=0;    //Turn off the display of the data tube, because my 51 corresponds to the input of the data tube

wela=0;    //So a latch lock is needed to turn off the impact

    Write1602_Com(SETMODE); //Mode setting

    delay(5);

    Write1602_Com(DISOPEN); //Display settings

    delay(5);

    Write1602_Com(DISMODE); //Display mode

    delay(5);

    Write1602_Com(CLEAR); //Clear the screen

    delay(5);

} 

void Write1602_Dat(uint8 dat)

{

    E=0;

    RS=1; //data

    delay(5); //Delay

    PORT=dat; //port assignment

    delay(5);

    E=1; //High pulse

    delay(5);

    E=0;

} 

void Write1602_Com(uint8 com)

{

    E=0;

    RS=0; //Command

    delay(5); //Delay

    PORT=com; //port assignment

    delay(5);

    E=1; //High pulse

    delay(5);

    E=0;

}

void Write1602_Str(uint8 addr,uint8 length,uint8 *pbuf)

{

    uint8 i; 

    Write1602_Com(addr);

    for(i=0;i 

    {

       Write1602_Dat(pbuf[i]);

    }

} 

Effect

A bit ugly. . . . It’s a font issue, so you can design it yourself.

Summarize:

1. Design font templates for custom characters and obtain character codes

2. Write the character code in the corresponding position of CGRAM

3. Write the address corresponding to CGRAM in DDRAM