单片机习题,按下矩阵按钮后,在2个数码管上显示按键值0到15。

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#include <reg52.h>sbit ADDR0 = P1^0;sbit ADDR1 = P1^1;sbit ADDR2 = P1^2;sbit ADDR3 = P1^3;sbit ENLED = P1^4;sbit KEY_IN_1 = P2^4;sbit KEY_IN_2 = P2^5;sbit KEY_IN_3 = P2^6;sbit KEY_IN_4 = P2^7;sbit KEY_OUT_1 = P2^3;sbit KEY_OUT_2 = P2^2;sbit KEY_OUT_3 = P2^1;sbit KEY_OUT_4 = P2^0;unsigned char code LedChar[] = { //数码管显示字符转换表 0xC0, 0xF9, 0xA4, 0xB0, 0x99, 0x92, 0x82, 0xF8, 0x80, 0x90, 0x88, 0x83, 0xC6, 0xA1, 0x86, 0x8E};unsigned char KeySta[4][4] = { //全部矩阵按键的当前状态 {1, 1, 1, 1}, {1, 1, 1, 1}, {1, 1, 1, 1}, {1, 1, 1, 1}};void main(){ unsigned char i, j; unsigned char backup[4][4] = { //按键值备份，保存前一次的值 {1, 1, 1, 1}, {1, 1, 1, 1}, {1, 1, 1, 1}, {1, 1, 1, 1} }; EA = 1; //使能总中断 ENLED = 0; //选择数码管DS1进行显示 ADDR3 = 1; ADDR2 = 0; ADDR1 = 0; ADDR0 = 0; TMOD = 0x01; //设置T0为模式1 TH0 = 0xFC; //为T0赋初值0xFC67，定时1ms TL0 = 0x67; ET0 = 1; //使能T0中断 TR0 = 1; //启动T0 P0 = LedChar[0]; //默认显示0 while (1) { for (i=0; i<4; i++) //循环检测4*4的矩阵按键 { for (j=0; j<4; j++) { if (backup[i][j] != KeySta[i][j]) //检测按键动作 { if (backup[i][j] != 0) //按键按下时执行动作 { P0 = LedChar[i*4+j]; //将编号显示到数码管 } backup[i][j] = KeySta[i][j]; //更新前一次的备份值 } } } }}/* T0中断服务函数，扫描矩阵按键状态并消抖 */void InterruptTimer0() interrupt 1{ unsigned char i; static unsigned char keyout = 0; //矩阵按键扫描输出索引 static unsigned char keybuf[4][4] = { //矩阵按键扫描缓冲区 {0xFF, 0xFF, 0xFF, 0xFF}, {0xFF, 0xFF, 0xFF, 0xFF}, {0xFF, 0xFF, 0xFF, 0xFF}, {0xFF, 0xFF, 0xFF, 0xFF} }; TH0 = 0xFC; //重新加载初值 TL0 = 0x67; //将一行的4个按键值移入缓冲区 keybuf[keyout][0] = (keybuf[keyout][0] << 1) | KEY_IN_1; keybuf[keyout][1] = (keybuf[keyout][1] << 1) | KEY_IN_2; keybuf[keyout][2] = (keybuf[keyout][2] << 1) | KEY_IN_3; keybuf[keyout][3] = (keybuf[keyout][3] << 1) | KEY_IN_4; //消抖后更新按键状态 for (i=0; i<4; i++) //每行4个按键，所以循环4次 { if ((keybuf[keyout][i] & 0x0F) == 0x00) { //连续4次扫描值为0，即4*4ms内都是按下状态时，可认为按键已稳定的按下 KeySta[keyout][i] = 0; } else if ((keybuf[keyout][i] & 0x0F) == 0x0F) { //连续4次扫描值为1，即4*4ms内都是弹起状态时，可认为按键已稳定的弹起 KeySta[keyout][i] = 1; } } //执行下一次的扫描输出 keyout++; //输出索引递增 keyout = keyout & 0x03; //索引值加到4即归零 switch (keyout) //根据索引，释放当前输出引脚，拉低下次的输出引脚 { case 0: KEY_OUT_4 = 1; KEY_OUT_1 = 0; break; case 1: KEY_OUT_1 = 1; KEY_OUT_2 = 0; break; case 2: KEY_OUT_2 = 1; KEY_OUT_3 = 0; break; case 3: KEY_OUT_3 = 1; KEY_OUT_4 = 0; break; default: break; }}这里的ADDR 和ENLED 是控制的数码管的位选和段选，，，，因为是用到了38译码器， 你这里可以根据自己电路的连接方式自己更改下，，，数码管的扫描显示方式 是一样的