STM8控制LCD12864液晶屏实验

2021-09-02 来源：eefocus

第一部分并口传输显示中英文

主要是以下几个函数:

首先：写一个LCD_write函数来给LCD发送数据.根据时序图，发送数据是RW要置0，E要产生下降沿，RS置1为数据，RS置0为命令，由于是并口传输PSB置1.

其次：能够给LCD发命令后，我们就要使用LCD_init函数发送初始化命令。初始化命令至少包括：1、设置显示，2、功能设定，3、初始化清屏3个部分。

写命令时注意每个命令都有自己的运行时间，记得保证足够延时。

第三：写一个LCD_display函数可以分行分列显示内容。

void LCD_write(u8 data,u8 cmd_flag);

void LCD_init(void);

void LCD_display(u8 row,u8 col,u8 *string);

一、并口方式理论及资料

1.先上时序图：

这里要注意的是 PWeh 要大于450ns 以STM8S208MB内部16M RC振荡器计算，每次执行时间为： 1s/(16M/8分频) =500ns 所以必须延时保证E引脚上升区域大于450ns。

同理 tdsw也需要延时。

2.指令表

ST7920指令集分为2种，第一种：10种基础指令集RE=0，第二种：6种高级指令集RE=0

第一部分是显示中英文，所以只需用到基础指令集RE=0

3.引脚图和硬件电路

4.为什么每行可以写八个汉字或16个英文/数字？

因为每个汉字需要占2个字节。

此外还要留意，第一行和第三行的内存地址是连在一起的，不控制光标的话，写完第一行就会换行到第三行。（光标写完是自动加一的）

5.程序代码

//------------------------------header------------------------------------------

#include 'iostm8s208mb.h'

//------------------------------common datatype---------------------------------

typedef unsigned char uint8_t;

typedef unsigned short uint16_t;

typedef unsigned long uint32_t;

#define u8 uint8_t

#define u16 uint16_t

#define u32 uint32_t

//------------------------------macros------------------------------------------

#define LCDRS PF_ODR_ODR0

#define LCDRW PF_ODR_ODR3

#define LCDEN PF_ODR_ODR4

#define LCDPSB PF_ODR_ODR5

#define LCDDATA PB_ODR

//------------------------------function declare--------------------------------

void delay(u8 count);

void GPIO_init(void);

void LCD_write(u8 data,u8 cmd_flag);

void LCD_init(void);

void LCD_display(u8 row,u8 col,u8 *string);

//------------------------------global------------------------------------------

//------------------------------main--------------------------------------------

void main( void )

{

GPIO_init();

LCD_init();

LCD_display(1,0,'熊爸的学习时间');

LCD_display(2,0,'================');

LCD_display(3,0,'使用LCD12864显示');

LCD_display(4,0,'屏来并口显示数据');

}

//------------------------------functions---------------------------------------

void delay(u8 count)

{

u8 i,j;

while (count--)

{

for(i=0;i<50;i++)

for(j=0;j<20;j++);

}

void GPIO_init(void)

{

//lcd DB0~DB7

PB_DDR |=0XFF;

PB_CR1 |=0XFF;

PB_CR2 &=0X00;

PB_ODR &=0X00;

//LCD RS RW EN PSB

PF_DDR |=0X39;

PF_CR1 |=0X39;

PF_CR2 &=0XC6;

PF_ODR &=0XC6;

LCDPSB=1;

LCDRW=0;

}

void LCD_write(u8 data,u8 cmd_flag)

{

LCDRS=cmd_flag;

LCDEN=0;

delay(1);

LCDEN=1;

LCDDATA=data;

delay(1); //delay保证E的周期

LCDEN=0;

delay(1);

}

void LCD_init(void)

{

LCD_write(0X0C,0);

delay(1);

LCD_write(0X30,0);

delay(1);

LCD_write(0X01,0);

delay(1);

}

void LCD_display(u8 row,u8 col,u8 *string)

{

switch (row)

{

case 1:row=0X80;break;

case 2:row=0X90;break;

case 3:row=0X88;break;

case 4:row=0X98;break;

default:row=0X80;

}

LCD_write(row+col,0);

while (*string != '')

{

LCD_write(*string,1);

string++;

}

5.实验效果

第二部分并行显示图片

1、指令集

使用绘图功能需要打开扩展指令集

2、绘画步骤

1.使用扩展指令集并关闭绘图显示功能 0X34
2.设置垂直地址
3.设置水平地址
4.写D15~D8位
5.写D7~D0位
6.打开绘图显示功能 0X36
7.返回基本指令集

垂直地址：表示方法第几行+偏移量例如： 0x80+j

水平地址：第一行0X80 第二行0X90 第三行0X88 第四行0X98

这部分处理函数如下：

void LCD_pic(u8 *pic)

{

u8 i,j,k;

LCD_write(0X34,0);delay(10);

for ( i = 0; i <2; i++)

{

for ( j = 0; j <32; j++)

{

LCD_write(0X80+j,0);

LCD_write(0X80+8*i,0);

for ( k = 0; k <16; k++)

{

LCD_write(*pic++,1);

}

LCD_write(0X36,0);delay(10);

LCD_write(0X30,0);delay(10);

}

3、再来看GDRAM

其实12864 只用了GDRAM的一半

Y坐标取值范围：0X80+0-31

X坐标取值范围：0X80或者0X88

//------------------------------header------------------------------------------

#include 'iostm8s208mb.h'

//------------------------------common datatype---------------------------------

typedef unsigned char uint8_t;

typedef unsigned short uint16_t;

typedef unsigned long uint32_t;

#define u8 uint8_t

#define u16 uint16_t

#define u32 uint32_t

//------------------------------macros------------------------------------------

#define LCDRS PF_ODR_ODR0

#define LCDRW PF_ODR_ODR3

#define LCDEN PF_ODR_ODR4

#define LCDPSB PF_ODR_ODR5

#define LCDDATA PB_ODR

//------------------------------function declare--------------------------------

void delay(u8 count);

void GPIO_init(void);

void LCD_write(u8 data,u8 cmd_flag);

void LCD_init(void);

void LCD_pic(u8 *pic);

//------------- -----------------global------------------------------------------

u8 dis[]={0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,

0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,

0x00,0x00,0x03,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,

0x00,0x00,0x0F,0xC0,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,

0x00,0x00,0x1F,0xE0,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,

0x00,0x00,0x3F,0xF0,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,

0x00,0x00,0xFF,0xFE,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,

0x00,0x03,0xFF,0xFF,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,

0x00,0x0F,0xFC,0xFF,0xE0,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,

0x00,0x3F,0xF8,0x7F,0xF0,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,

0x00,0xFF,0xC3,0x0F,0xFC,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,

0x01,0xFF,0xC7,0x8F,0xFE,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,

0x07,0xFE,0x3F,0xF1,0xFF,0x80,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,

0x07,0xFC,0x3F,0xF0,0xFF,0x80,0x03,0x00,0x00,0x00,0x30,0x60,0x00,0x00,0x00,0x00,

0x07,0xE3,0xFF,0xFF,0x1F,0x80,0x03,0x00,0x63,0xFC,0x30,0xE0,0x30,0xC4,0x08,0x60,

0x07,0xE3,0xFF,0xFF,0x8F,0x80,0xFF,0xFC,0x63,0x0C,0x30,0xC0,0xC6,0xFC,0x7C,0xF8,

0x07,0x8F,0xFC,0xFF,0xE7,0x80,0xC0,0x0C,0x63,0x0C,0xFD,0xFC,0xFF,0xC8,0xF8,0x5C,

0x07,0x8F,0xF0,0x3F,0xE7,0x80,0xC6,0x0D,0xFB,0x0C,0xCD,0x8C,0x02,0xCC,0x4F,0xE0,

0x07,0x8F,0xC0,0x0F,0xE7,0x80,0x06,0x00,0x5B,0xFC,0xCF,0x8C,0xFE,0xFC,0x0F,0xE0,

0x07,0x8F,0x80,0x07,0xE7,0x80,0x0E,0x00,0xDB,0x00,0xCD,0x0C,0xC6,0xC5,0xFF,0xFE,

0x07,0x8F,0xC0,0x0F,0xE7,0x81,0xFF,0xFE,0xDB,0x60,0xCC,0x8C,0xFE,0xDC,0xF0,0x1C,

0x07,0x8F,0xF0,0x3F,0xE7,0x80,0x18,0x70,0xDB,0x6C,0xFD,0xCC,0xC6,0xF8,0x7F,0xF8,

0x07,0x8F,0xFC,0xFF,0xE7,0x80,0x38,0x60,0xDB,0x7C,0xCC,0xCC,0xFE,0xC4,0x63,0x18,

0x07,0x8F,0xFF,0xFF,0xE7,0x80,0x3E,0xE0,0xF3,0x78,0xCC,0xEC,0xC6,0xCC,0x63,0x18,

0x07,0x8F,0xFF,0xFF,0xE7,0x80,0x0F,0xC0,0x3F,0x70,0xCC,0x6C,0xDE,0xFC,0x7F,0xF8,

0x07,0x8F,0xFF,0xFF,0xE7,0x80,0x07,0xC0,0x7E,0x64,0xCC,0x4C,0x4C,0x98,0x60,0x0E,

0x07,0x8F,0x3F,0xF3,0xE7,0x80,0x1E,0xF0,0xF6,0x66,0xCC,0x0C,0xCC,0xCC,0x60,0x0C,

0x01,0x8F,0x0F,0xC3,0xE6,0x00,0x7C,0x39,0xCE,0x6C,0xFC,0x0C,0xCC,0xCC,0x70,0x1C,

0x00,0x8F,0x03,0x03,0xE4,0x00,0xE0,0x0C,0x84,0x7C,0xCC,0xF8,0x80,0x04,0x3F,0xF8,

0x06,0x0F,0x00,0x03,0xE1,0x80,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,

0x07,0x0F,0x00,0x03,0xC3,0x80,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,

0x07,0xE3,0x00,0x03,0x1F,0x80,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,

0x07,0xF1,0x00,0x02,0x3F,0x81,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFC,

0x07,0xFE,0x00,0x01,0xFF,0x80,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,

0x07,0xFF,0x00,0x03,0xFF,0x81,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFC,

0x01,0xFF,0xC0,0x0F,0xFE,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,

0x00,0x7F,0xE0,0x1F,0xF8,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,

0x00,0x1F,0xF8,0x7F,0xE0,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,

0x00,0x0F,0xFF,0xFF,0xC0,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,

0x00,0x01,0xFF,0xFF,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,

0x00,0x00,0xFF,0xFC,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,

0x00,0x00,0x3F,0xF0,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,

0x00,0x00,0x1F,0xE0,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,

0x00,0x00,0x07,0xC0,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,

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

0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,

0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00};

//------------------------------main--------------------------------------------

void main( void )

{

CLK_CKDIVR=0X00;

delay(100);

GPIO_init();

LCD_init();

LCD_pic(dis);

}

//------------------------------functions---------------------------------------

void delay(u8 count)

{

u8 i,j;

while (count--)

{

for(i=0;i<50;i++)

for(j=0;j<20;j++);

}

void GPIO_init(void)

{

//lcd DB0~DB7

PB_DDR |=0XFF;

PB_CR1 |=0XFF;

PB_CR2 &=0X00;

PB_ODR &=0X00;

//LCD RS RW EN PSB

PF_DDR |=0X39;

PF_CR1 |=0X39;

PF_CR2 &=0XC6;

PF_ODR &=0XC6;

LCDPSB=1;

LCDRW=0;

}

void LCD_write(u8 data,u8 cmd_flag)

{

LCDRS=cmd_flag;

LCDEN=0;

delay(1);

LCDDATA=data;

LCDEN=1;

delay(1);

LCDEN=0;

delay(1);

}

void LCD_init(void)

{

LCD_write(0X0C,0);

delay(1);

LCD_write(0X34,0);

delay(1);

LCD_write(0X01,0);

delay(1);

}

void LCD_pic(u8 *pic)

{

u8 i,j,k;

LCD_write(0X34,0);delay(10);

for ( i = 0; i <2; i++)

{

for ( j = 0; j <32; j++)

{

LCD_write(0X80+j,0);

LCD_write(0X80+8*i,0);

for ( k = 0; k <16; k++)

{

LCD_write(*pic++,1);

}

LCD_write(0X36,0);delay(10);

LCD_write(0X30,0);delay(10);

}

实验效果：

这里说一下怎么得到DIS数组的

用PS制作一张128*64的BMP图片

然后将其导入字模提取软件中用C51格式取模即可

第三部分串口传输

串口传输非常省GPIO，可以做到用两个GPIO控制整块显示屏。非常给力！

选择串口通讯模式需要把PSB置0（或接GND）

此时 RS变为了片选端口我们直接置1（或接VDD）

RW变成了SDIO 我们用它来发送数据（接GPIO）

把EN变成了SCLK 我们用它来给通讯时钟（接GPIO）

1. 串口输出时序图

比如我们发送一个命令 0X34到LCD，可以

11111 0 0 0 （命令控制字）0XF8

0011 0000 ( 0X34的高4位) 0X30

0100 0000( 0X34的低4位) 0X40

通过仔细观察时序图，我们发现：时钟为0时可以改变数据，时钟为1时采集。所以大体思路是在CLK=0时装载，在CLK=1时发射。

2. 需要写的函数

通过上面的分析总结出我们需要以下函数：

① 一个将命令/数据分解成3个字节并发送的处理函数

void LCD_write(u8 data,u8 cmd_flag)

{

if(cmd_flag)

LCD_send_byte(0XFA);

else

LCD_send_byte(0XF8);

LCD_send_byte(data & 0XF0);

LCD_send_byte((data<<4) & 0XF0);

}

②一个控制时钟引脚并将数据在SDIO口逐位发送的函数

LCD_send_byte(u8 byte)

{

for (u8 i = 0; i < 8; i++)

{

LCDCLK=0;

if ((byte< LCDDIO=1;

else

LCDDIO=0;

LCDCLK=1;

}

3.程序（用并行显示图片程序改的）

//------------------------------header------------------------------------------

#include 'iostm8s208mb.h'

//------------------------------common datatype---------------------------------

typedef unsigned char uint8_t;

typedef unsigned short uint16_t;

typedef unsigned long uint32_t;

#define u8 uint8_t

#define u16 uint16_t

#define u32 uint32_t

//------------------------------macros------------------------------------------

#define LCDCS PF_ODR_ODR0

#define LCDDIO PF_ODR_ODR3

#define LCDCLK PF_ODR_ODR4

#define LCDPSB PF_ODR_ODR5

//------------------------------function declare--------------------------------

void delay(u8 count);

void GPIO_init(void);

void LCD_write(u8 data,u8 cmd_flag);

void LCD_init(void);

void LCD_pic(u8 *pic);

void LCD_send_byte(u8 byte);