#include <reg52.h>
sbit ADDR0 = P1^0;
sbit ADDR1 = P1^1;
sbit ADDR2 = P1^2;
sbit ADDR3 = P1^3;
sbit ENLED = P1^4;
sbit KEY1 = P2^4;
sbit KEY2 = P2^5;
sbit KEY3 = P2^6;
sbit KEY4 = P2^7;
unsigned char code LedChar[] = { //數碼管顯示字符轉換表
0xC0, 0xF9, 0xA4, 0xB0, 0x99, 0x92, 0x82, 0xF8,
0x80, 0x90, 0x88, 0x83, 0xC6, 0xA1, 0x86, 0x8E
};
void delay();
void main(){
bit keybuf = 1; //按鍵值暫存，臨時保存按鍵的掃描值
bit backup = 1; //按鍵值備份，保存前一次的掃描值
unsigned char cnt = 0; //按鍵計數，記錄按鍵按下的次數
ENLED = 0; //選擇數碼管 DS1 進行顯示
ADDR3 = 1;
ADDR2 = 0;
ADDR1 = 0;
ADDR0 = 0;
P2 = 0xF7; //P2.3 置 0，即 KeyOut1 輸出低電平
P0 = LedChar[cnt]; //顯示按鍵次數初值
while (1){
keybuf = KEY4; //把當前掃描值暫存
if (keybuf != backup){ //當前值與前次值不相等說明此時按鍵有動作
delay(); //延時大約 10ms
if (keybuf == KEY4){ //判斷掃描值有沒有發生改變，即按鍵抖動
if (backup == 0){ //如果前次值為 0，則說明當前是彈起動作
cnt++; //按鍵次數+1
//只用 1 個數碼管顯示，所以加到 10 就清零重新開始
if (cnt >= 10){
cnt = 0;
}
P0 = LedChar[cnt]; //計數值顯示到數碼管上
}
backup = keybuf; //更新備份為當前值，以備進行下次比較
}
}
}
}
/* 軟件延時函數，延時約 10ms */
void delay(){
unsigned int i = 1000;
while (i--);
} |
