51系列单片机是很古老的单片机了。虽然古老，但在测使用上还是有一定优势的。我在买了电子模块时，一般首选ESP8266，使用ARduino开发环境进行测试。但有时候也会选用51单片机编程测试。主要是自己用51单片机很多年，51单片机的IO口控制指令很简单，不像Arm芯片那样，需要配置很多东西。这不最近和显示屏杠上了，买了很多显示屏玩，有OLED的，LCD的，也有TFT的。有I2C接口的，有SPI接口的，也有RGB并口的。买来了肯定是要测试的，玩的同时，也算是积累经验吧。
以下是一款1.3寸的240*240的显示屏，SPI接口：
接口定义如下：
驱动芯片是ST7789
程序使用IO口模拟SPI方式：
//1.3寸TFT_ST7735液晶驱动
#include<reg52.h>
#include<absacc.h>
#include<intrins.h>
#include<string.h>
#include<font.h>
#include <I2C.h> //I2C协议
#include <Delay.h> //延时模块
#include <debug.h> //延时模块
#define uchar unsigned char
#define uint unsigned int
#define LEDS P2
//测试硬件平台：IAP15W4K58S4
//主频：11.0594MHZ
//单片机IO推挽输出设置定义
//#define USE_LANDSCAPE//测试程序横竖屏切换，横屏请开启此宏，竖屏请屏蔽
//---------------------------液晶屏接线说明-------------------------------------//
//接线前请参考液晶屏说明书第10页引脚定义
sbit bl =P1^4;//接模块BL引脚，背光可以采用IO控制或者PWM控制，也可以直接接到高电平常亮
sbit scl =P1^0;//接模块CLK引脚,接裸屏Pin9_SCL
sbit sda =P1^1;//接模块DIN/MOSI引脚，接裸屏Pin8_SDA
sbit rs =P1^3;//接模块D/C引脚，接裸屏Pin7_A0
sbit cs =P1^7;//接模块CE引脚，接裸屏Pin12_CS
sbit reset =P1^2;//接模块RST引脚，接裸屏Pin6_RES
//---------------------------End of液晶屏接线---------------------------------//
//定义常用颜色
#define RED 0xf800
#define GREEN0x07e0
#define BLUE 0x001f
#define WHITE0xffff
#define BLACK0x0000
#define YELLOW 0xFFE0
#define GRAY0 0xEF7D
#define GRAY1 0x8410
#define GRAY2 0x4208
void Contrast_Adjust();
code typFNT_GBK16 hz16[];
void Output_Pixel(uint x,uint y);
void delay_ms(uint time) {
uint i,j;
for(i=0;i<time;i++)
for(j=0;j<250;j++);
}
//向SPI总线传输一个8位数据
void SPI_WriteData(uchar Data) {
unsigned char i=0;
for(i=8;i>0;i--) {
if(Data&0x80)
sda=1; //输出数据
else sda=0;
scl=0;
scl=1;
Data<<=1;
}
}
//向液晶屏写一个8位指令
void Lcd_WriteIndex(uchar Data) {
cs=0;
rs=0;
SPI_WriteData(Data);
cs=1;
}
//向液晶屏写一个8位数据
void Lcd_WriteData(uchar Data) {
unsigned char i=0;
cs=0;
rs=1;
SPI_WriteData(Data);
cs=1;
}
//向液晶屏写一个16位数据
void LCD_WriteData_16Bit(unsigned int Data) {
unsigned char i=0;
cs=0;
rs=1;
SPI_WriteData(Data>>8); //写入高8位数据
SPI_WriteData(Data); //写入低8位数据
cs=1;
}
void Reset() {
reset=0;
delay_ms(100);
reset=1;
delay_ms(100);
}
//////////////////////////////////////////////////////////////////////////////////////////////
//液晶屏初始化 for S6D02A1
void lcd_initial() {
Reset();//Reset before LCD Init.
//Lcd_WriteIndex(0x11);//Sleep exit
delay_ms (120);
Lcd_WriteIndex(0x36);
Lcd_WriteData(0x00);
Lcd_WriteIndex(0x3A);
Lcd_WriteData(0x05);
Lcd_WriteIndex(0xB2);
Lcd_WriteData(0x0C);
Lcd_WriteData(0x0C);
Lcd_WriteData(0x00);
Lcd_WriteData(0x33);
Lcd_WriteData(0x33);
Lcd_WriteIndex(0xB7);
Lcd_WriteData(0x35);
Lcd_WriteIndex(0xBB);
Lcd_WriteData(0x19);
Lcd_WriteIndex(0xC0);
Lcd_WriteData(0x2C);
Lcd_WriteIndex(0xC2);
Lcd_WriteData(0x01);
Lcd_WriteIndex(0xC3);
Lcd_WriteData(0x12);
Lcd_WriteIndex(0xC4);
Lcd_WriteData(0x20);
Lcd_WriteIndex(0xC6);
Lcd_WriteData(0x0F);
Lcd_WriteIndex(0xD0);
Lcd_WriteData(0xA4);
Lcd_WriteData(0xA1);
Lcd_WriteIndex(0xE0);
Lcd_WriteData(0xD0);
Lcd_WriteData(0x04);
Lcd_WriteData(0x0D);
Lcd_WriteData(0x11);
Lcd_WriteData(0x13);
Lcd_WriteData(0x2B);
Lcd_WriteData(0x3F);
Lcd_WriteData(0x54);
Lcd_WriteData(0x4C);
Lcd_WriteData(0x18);
Lcd_WriteData(0x0D);
Lcd_WriteData(0x0B);
Lcd_WriteData(0x1F);
Lcd_WriteData(0x23);
Lcd_WriteIndex(0xE1);
Lcd_WriteData(0xD0);
Lcd_WriteData(0x04);
Lcd_WriteData(0x0C);
Lcd_WriteData(0x11);
Lcd_WriteData(0x13);
Lcd_WriteData(0x2C);
Lcd_WriteData(0x3F);
Lcd_WriteData(0x44);
Lcd_WriteData(0x51);
Lcd_WriteData(0x2F);
Lcd_WriteData(0x1F);
Lcd_WriteData(0x1F);
Lcd_WriteData(0x20);
Lcd_WriteData(0x23);
Lcd_WriteIndex(0x21);
Lcd_WriteIndex(0x11);
Lcd_WriteIndex(0x29);
}
/*************************************************
函数名：LCD_Set_Region
功能：设置lcd显示区域，在此区域写点数据自动换行
入口参数：xy起点和终点
返回值：无
*************************************************/
void Lcd_SetRegion(unsigned int x_start,unsigned int y_start,unsigned int x_end,unsigned int y_end) {
Lcd_WriteIndex(0x2a);
Lcd_WriteData(0x00);
Lcd_WriteData(x_start);
Lcd_WriteData(0x00);
Lcd_WriteData(x_end);
Lcd_WriteIndex(0x2b);
Lcd_WriteData(0x00);
Lcd_WriteData(y_start);
Lcd_WriteData(0x00);
Lcd_WriteData(y_end);
Lcd_WriteIndex(0x2c);
}
void PutPixel(uint x_start,uint y_start,uint color) {
Lcd_SetRegion(x_start,y_start,x_start+1,y_start+1);
LCD_WriteData_16Bit(color);
}
void dsp_single_colour(int color) {
uchar i,j;
Lcd_SetRegion(0,0,240-1,240-1);
for (i=0;i<240;i++)
for (j=0;j<240;j++)
LCD_WriteData_16Bit(color);
}
//采用设置窗口方法填充字库数据，相比Gui_DrawFont_GBK16更快速
//x:水平方向上的坐标
//y:垂直方向上的坐标
void Fast_DrawFont_GBK16(uint x, uint y, uint fc, uint bc, uchar *s) {
unsigned char i,j;
unsigned short k;
uint HZnum;
HZnum=sizeof(hz16)/sizeof(typFNT_GBK16);
while(*s) {
if((*s) >= 128) {
for (k=0;k<HZnum;k++) {
if ((hz16[k].Index[0]==*(s))&&(hz16[k].Index[1]==*(s+1))) { Lcd_SetRegion(x,y,x+16-1,y+16-1);
for(i=0;i<16*2;i++) {
for(j=0;j<8;j++) {
if(hz16[k].Msk[i]&(0x80>>j))
LCD_WriteData_16Bit(fc);
else {
if (fc!=bc)
LCD_WriteData_16Bit(bc);
}
}
}
}
}
s+=2;x+=16;
} else {
s+=1;
}
}
}
//此方法描绘汉字较慢
void Gui_DrawFont_GBK16(uint x, uint y, uint fc, uint bc, uchar *s) {
unsigned char i,j;
unsigned short k,x0;
x0=x;
while(*s) {
if((*s) >= 128) {
for (k=0;k<hz16_num;k++) {
if ((hz16[k].Index[0]==*(s))&&(hz16[k].Index[1]==*(s+1))) {
for(i=0;i<16;i++) {
for(j=0;j<8;j++) {
if(hz16[k].Msk[i*2]&(0x80>>j))
PutPixel(x+j,y+i,fc);
else
if (fc!=bc)
PutPixel(x+j,y+i,bc);
}
for(j=0;j<8;j++) {
if(hz16[k].Msk[i*2+1]&(0x80>>j))
PutPixel(x+j+8,y+i,fc);
else
if (fc!=bc)
PutPixel(x+j+8,y+i,bc);
}
}
}
}
s+=2;x+=16;
} else {
s+=1;
}
}
}
//清屏函数
//Color:要清屏的填充色
void LCD_Clear(uint Color) {
uint i,j;
Lcd_SetRegion(0,0,240-1,240-1);
for(i=0;i<240;i++) {
for (j=0;j<240;j++) {
LCD_WriteData_16Bit(Color);
}
}
}
main() {
lcd_initial();
bl=1;
LCD_Clear(BLACK); //清屏
Fast_DrawFont_GBK16(8,10, BLUE, WHITE,"中文测试");
delay_ms(5000);
while(1) {
}
}显示效果（文字很小）：
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