Single chip microcomputer controls LCD1602 to display characters (test passed)-EEWORLD

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This test is on the commonly used LCD1602 display screen. The operation process is very simple, but there are some minor issues to pay attention to. For example, the LCD processing speed is a bit slow, and the microcontroller needs to delay appropriately when sending control instructions, otherwise the operation may fail.

1. Hardware Introduction

1>Pin Introduction

The specific pins are as follows:

The pins that need to be operated on the microcontroller are: RS, RW, E and DB0~7

2>Instruction Introduction

Here, let’s just introduce what is CGRAM and what is DDRAM?

CGRAM: It is a user-defined character storage memory. You can define characters at the specified address.

DDRAM: It is a memory corresponding to the screen position. By setting this address, it is determined where on the screen the characters will be displayed.

2. Software

#include
#include
#define DATA P0
sbit RS=P2^6;
sbit RW=P2^5;
sbit EN=P2^7;
unsigned char zifu[]={"Hello,World!0"};
unsigned char wangzhi[]={"http://shop108408772.taobao.com/"};
void delayms(unsigned char m) //适当延时
{unsigned char i;
while(m--)
{
for(i=0;i<=250;i++)
{_nop_();
}
}
}
void WRITE_BYTE(unsigned char canshu) //写1个字节
{
RW=0;
_nop_();
_nop_();
EN=1;
_nop_();
DATA=canshu;
EN=0;
_nop_();
_nop_();
}

void main()
{
unsigned char *point;
RS=0;
WRITE_BYTE(1); //Clear screen
delayms(10); //About 23ms delay
WRITE_BYTE(2); //Cursor home
delayms(10);
WRITE_BYTE(6);   // AC automatically increases by 1, screen does not move
delayms(10);
WRITE_BYTE(0x0F); //Cursor display flashes
delayms(10);
WRITE_BYTE(0x14);   //Cursor moves right
delayms(10);
WRITE_BYTE(0x38); //Two lines display, 5X7 characters
delayms(10);
WRITE_BYTE(0x80);   //Set DDRAM address
delayms(10);
_nop_();
point=wangzhi;
while(*point!='') //Hello, world!，http: //shop108408772.taobao.com
{RS=1;
_nop_();
WRITE_BYTE(*point);
point=point+1;
delayms(10);
if(point==wangzhi+16)
{RS=0;
WRITE_BYTE(0xC0);   //Set the DDRAM address to the first character of the downstream
delayms(10);
}
}
while(1);
}

3. Problems in testing

1> Pay attention to the appropriate delay after each instruction, otherwise the operation will go wrong

2> In this test, the busy flag is not read, and the direct delay and operation can basically pass

4. Test Results

Reference address：Single chip microcomputer controls LCD1602 to display characters (test passed)

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