键盘扫描及动态LED 显示实验报告

《单片机》实验报告

一.实验题目

实验4.7 7279 键盘扫描及动态LED 显示实验

二.实验要求

本实验利用7279 进行键盘扫描及动态LED 数码管显示控制。

三.实验源程序

#include

//*** 函数定义***

void long_delay(void); // 长延时

void short_delay(void); // 短暂延时

void delay10ms(unsigned char); // 延时10MS

void write7279(unsigned char, unsigned char); // 写入到HD7279

unsigned char read7279(unsigned char); // 从HD7279读出

void send_byte(unsigned char); // 发送一个字节

#define uchar unsigned char

#define uint unsigned int

uchar

bianma[]={0x1b,0x13,0x0b,0x03,0x1a,0x12,0x0a,0x02,0x19,0x11,0x09,0x01,0x18,0x10,0x08,0x 00};

unsigned char receive_byte(void); // 接收一个字节

//*** 变量及I/O口定义***

unsigned char digit[5];

unsigned char key_number, j, k,mk; //mk为按键次数计数值

unsigned int tmr;

unsigned long wait_cnter;

sbit cs=P1^0; // cs at P1.0

sbit clk=P1^1; // clk 连接于P1.1

sbit dat=P1^2; // dat 连接于P1.2

sbit key=P1^3; // key 连接于P1.3

void write7279(unsigned char cmd, unsigned char dta) {

send_byte (cmd);

send_byte (dta);

}

unsigned char read7279(unsigned char command) {

send_byte(command);

return(receive_byte());

}

void send_byte( unsigned char out_byte)

{

unsigned char i;

cs=0;//芯片使能

long_delay();

for (i=0;i<8;i++) //分8次移入数据

{

if (out_byte&0x80)//先传高位

{

dat=1;

}

else

{

dat=0;

}

clk=1;

short_delay();

clk=0;

short_delay();

out_byte=out_byte*2;//数据左移

}

dat=0;

}

unsigned char receive_byte(void)

{

unsigned char i, in_byte;

dat=1; // set to input mode

long_delay();

for (i=0;i<8;i++)//分8次读入数据高位在前

{

clk=1;

short_delay();

in_byte=in_byte*2; //数据左移

if (dat)

{

in_byte=in_byte|0x01;

}

clk=0;

short_delay();

}

dat=0;

return (in_byte);

}

void long_delay(void)

{

unsigned char i;

for (i=0;i<0x30;i++);

}

void short_delay(void)

{

unsigned char i;

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

}

void main(){

uchar jianpan,i,num;

send_byte(0xa4); //全部复位指令

while(1){

if(key==0){ //如果按键按下

send_byte(0x15); //读键盘指令

jianpan=receive_byte(); //接收键盘数据// P0=num;

for(i=0;i<16;i++){

if(jianpan==bianma[i]){ //等于判断一定是双等于号

num=i;

break;

}

}

send_byte(0xa1);

write7279(0xc8,num);

while(key==0);

}

} }