单片机实例33——4×4键盘及8位数码管显示构成的电子密码锁（硬件电路图+C语言程序）

密码锁（硬件电路图+C语言程序）"/>

单片机实例33——4×4键盘及8位数码管显示构成的电子密码锁（硬件电路图+C语言程序）

33． 4×4键盘及8位数码管显示构成的电子密码锁

1． 实验任务

用4×4组成0－9数字键及确认键。

用8位数码管组成显示电路提示信息，当输入密码时，只显示“8.”，当密码位数输入完毕按下确认键时，对输入的密码与设定的密码进行比较，若密码正确，则门开，此处用LED发光二极管亮一秒钟做为提示，同时发出“叮咚”声；若密码不正确，禁止按键输入3秒，同时发出“嘀、嘀”报警声；若在3秒之内仍有按键按下，则禁止按键输入3秒被重新禁止。

2． 电路原理图

图4.33.1

3． 系统板上硬件连线

（1）． 把“单片机系统”区域中的P0.0－P0.7用8芯排线连接到“动态数码显示”区域中的ABCDEFGH端子上。

（2）． 把“单片机系统“区域中的P2.0－P2.7用8芯排线连接到“动态数码显示”区域中的S1S2S3S4S5S6S7S8端子上。

（3）． 把“单片机系统”区域中的P3.0－P3.7用8芯排线连接到“4×4行列式键盘”区域中的R1R2R3R4C1C2C3C4端子上。

（4）． 把“单片机系统”区域中的P1.0用导线连接到“八路发光二极管模块”区域中的L2端子上。

（5）． 把“单片机系统”区域中的P1.7用导线连接到“音频放大模块”区域中的SPK IN端子上。

（6）． 把“音频放大模块”区域中的SPK OUT接到喇叭上。

4． 程序设计内容

（1）． 4×4行列式键盘识别技术：有关这方面内容前面已经讨论过，这里不再重复。

（2）． 8位数码显示，初始化时，显示“P　　　”，接着输入最大6位数的密码，当密码输入完后，按下确认键，进行密码比较，然后给出相应的信息。在输入密码过程中，显示器只显示“8.”。当数字输入超过6个时，给出报警信息。在密码输入过程中，若输入错误，可以利用“DEL”键删除刚才输入的错误的数字。

（3）． 4×4行列式键盘的按键功能分布图如图4.33.2所示：

图4.33.2

5． C语言源程序

#include <AT89X52.H>unsigned char ps[] = { 1,2,3,4,5 };unsigned char code dispbit[] = { 0xfe,0xfd,0xfb,0xf7,
0xef,0xdf,0xbf,0x7f };
unsigned char code dispcode[] = { 0x3f,0x06,0x5b,0x4f,0x66,
0x6d,0x7d,0x07,0x7f,0x6f,
0x77,0x7c,0x39,0x5e,0x79,0x71,
0x00,0x40,0x73,0xff };
unsigned char dispbuf[8] = { 18,16,16,16,16,16,16,16 };
unsigned char dispcount;
unsigned char flashcount;
unsigned char temp;
unsigned char key;
unsigned char keycount;
unsigned char pslen = 5;
unsigned char getps[6];
bit keyoverflag;
bit errorflag;
bit rightflag;
unsigned int second3;
unsigned int aa, bb;
unsigned int cc;
bit okflag;
bit alarmflag;
bit hibitflag;
unsigned char oka, okb;void main(void)
{unsigned char i, j;TMOD = 0x01;TH0 = (65536 - 500) / 256;TL0 = (65536 - 500) % 256;TR0 = 1;ET0 = 1;EA = 1;while (1){P3 = 0xff;P3_4 = 0;temp = P3;temp = temp & 0x0f;if (temp != 0x0f){for (i = 10; i > 0; i--)for (j = 248; j > 0; j--);temp = P3;temp = temp & 0x0f;if (temp != 0x0f){temp = P3;temp = temp & 0x0f;switch (temp){case 0x0e:key = 7;break;case 0x0d:key = 8;break;case 0x0b:key = 9;break;case 0x07:key = 10;break;}temp = P3;P1_1 = ~P1_1;if ((key >= 0) && (key < 10)){if (keycount < 6){getps[keycount] = key;dispbuf[keycount + 2] = 19;}keycount++;if (keycount == 6){keycount = 6;}else if (keycount > 6){keycount = 6;keyoverflag = 1;//key overflow}}else if (key == 12)//delete key{if (keycount > 0){keycount--;getps[keycount] = 0;dispbuf[keycount + 2] = 16;}else{keyoverflag = 1;}}else if (key == 15)//enter key{if (keycount != pslen){errorflag = 1;rightflag = 0;second3 = 0;}else{for (i = 0; i < keycount; i++){if (getps[i] != ps[i]){i = keycount;errorflag = 1;rightflag = 0;second3 = 0;goto a;}}errorflag = 0;rightflag = 1;a: i = keycount;}}temp = temp & 0x0f;while (temp != 0x0f){temp = P3;temp = temp & 0x0f;}keyoverflag = 0;//?????????}}P3 = 0xff;P3_5 = 0;temp = P3;temp = temp & 0x0f;if (temp != 0x0f){for (i = 10; i > 0; i--)for (j = 248; j > 0; j--);temp = P3;temp = temp & 0x0f;if (temp != 0x0f){temp = P3;temp = temp & 0x0f;switch (temp){case 0x0e:key = 4;break;case 0x0d:key = 5;break;case 0x0b:key = 6;break;case 0x07:key = 11;break;}temp = P3;P1_1 = ~P1_1;if ((key >= 0) && (key < 10)){if (keycount < 6){getps[keycount] = key;dispbuf[keycount + 2] = 19;}keycount++;if (keycount == 6){keycount = 6;}else if (keycount > 6){keycount = 6;keyoverflag = 1;//key overflow}}else if (key == 12)//delete key{if (keycount > 0){keycount--;getps[keycount] = 0;dispbuf[keycount + 2] = 16;}else{keyoverflag = 1;}}else if (key == 15)//enter key{if (keycount != pslen){errorflag = 1;rightflag = 0;second3 = 0;}else{for (i = 0; i < keycount; i++){if (getps[i] != ps[i]){i = keycount;errorflag = 1;rightflag = 0;second3 = 0;goto a4;}}errorflag = 0;rightflag = 1;a4: i = keycount;}}temp = temp & 0x0f;while (temp != 0x0f){temp = P3;temp = temp & 0x0f;}keyoverflag = 0;//?????????}}P3 = 0xff;P3_6 = 0;temp = P3;temp = temp & 0x0f;if (temp != 0x0f){for (i = 10; i > 0; i--)for (j = 248; j > 0; j--);temp = P3;temp = temp & 0x0f;if (temp != 0x0f){temp = P3;temp = temp & 0x0f;switch (temp){case 0x0e:key = 1;break;case 0x0d:key = 2;break;case 0x0b:key = 3;break;case 0x07:key = 12;break;}temp = P3;P1_1 = ~P1_1;if ((key >= 0) && (key < 10)){if (keycount < 6){getps[keycount] = key;dispbuf[keycount + 2] = 19;}keycount++;if (keycount == 6){keycount = 6;}else if (keycount > 6){keycount = 6;keyoverflag = 1;//key overflow}}else if (key == 12)//delete key{if (keycount > 0){keycount--;getps[keycount] = 0;dispbuf[keycount + 2] = 16;}else{keyoverflag = 1;}}else if (key == 15)//enter key{if (keycount != pslen){errorflag = 1;rightflag = 0;second3 = 0;}else{for (i = 0; i < keycount; i++){if (getps[i] != ps[i]){i = keycount;errorflag = 1;rightflag = 0;second3 = 0;goto a3;}}errorflag = 0;rightflag = 1;a3: i = keycount;}}temp = temp & 0x0f;while (temp != 0x0f){temp = P3;temp = temp & 0x0f;}keyoverflag = 0;//?????????}}P3 = 0xff;P3_7 = 0;temp = P3;temp = temp & 0x0f;if (temp != 0x0f){for (i = 10; i > 0; i--)for (j = 248; j > 0; j--);temp = P3;temp = temp & 0x0f;if (temp != 0x0f){temp = P3;temp = temp & 0x0f;switch (temp){case 0x0e:key = 0;break;case 0x0d:key = 13;break;case 0x0b:key = 14;break;case 0x07:key = 15;break;}temp = P3;P1_1 = ~P1_1;if ((key >= 0) && (key < 10)){if (keycount < 6){getps[keycount] = key;dispbuf[keycount + 2] = 19;}keycount++;if (keycount == 6){keycount = 6;}else if (keycount > 6){keycount = 6;keyoverflag = 1;//key overflow}}else if (key == 12)//delete key{if (keycount > 0){keycount--;getps[keycount] = 0;dispbuf[keycount + 2] = 16;}else{keyoverflag = 1;}}else if (key == 15)//enter key{if (keycount != pslen){errorflag = 1;rightflag = 0;second3 = 0;}else{for (i = 0; i < keycount; i++){if (getps[i] != ps[i]){i = keycount;errorflag = 1;rightflag = 0;second3 = 0;goto a2;}}errorflag = 0;rightflag = 1;a2: i = keycount;}}temp = temp & 0x0f;while (temp != 0x0f){temp = P3;temp = temp & 0x0f;}keyoverflag = 0;//?????????}}}
}void t0(void) interrupt 1 using 0
{TH0 = (65536 - 500) / 256;TL0 = (65536 - 500) % 256;flashcount++;if (flashcount == 8){flashcount = 0;P0 = dispcode[dispbuf[dispcount]];P2 = dispbit[dispcount];dispcount++;if (dispcount == 8){dispcount = 0;}}if ((errorflag == 1) && (rightflag == 0)){bb++;if (bb == 800){bb = 0;alarmflag = ~alarmflag;}if (alarmflag == 1)//sound alarm signal{P1_7 = ~P1_7;}aa++;if (aa == 800)//light alarm signal{aa = 0;P1_0 = ~P1_0;}second3++;if (second3 == 6400){second3 = 0;errorflag = 0;rightflag = 0;alarmflag = 0;bb = 0;aa = 0;}}else if ((errorflag == 0) && (rightflag == 1)){P1_0 = 0;cc++;if (cc < 1000){okflag = 1;}else if (cc < 2000){okflag = 0;}else{errorflag = 0;rightflag = 0;P1_7 = 1;cc = 0;oka = 0;okb = 0;okflag = 0;P1_0 = 1;}if (okflag == 1){oka++;if (oka == 2){oka = 0;P1_7 = ~P1_7;}}else{okb++;if (okb == 3){okb = 0;P1_7 = ~P1_7;}}}if (keyoverflag == 1){P1_7 = ~P1_7;}
}