三个IO口驱动两片74LS165,拓展为16位按键。附件包括Proteus仿真文件及源程序。
仿真原理图如下(proteus仿真工程文件可到本帖附件中下载)
单片机源程序如下:
代码:
- #include <reg52.h>
- #define uint16 unsigned int
- #define uint8 unsigned char
- sbit HC165_nPL = P3 ^ 5;
- sbit HC165_CK = P3 ^ 6;
- sbit HC165_OUT = P3 ^ 7;
- unsigned int HC165(void)
- {
- unsigned char i;
- unsigned int Temp, Temp1, Temp2;
- HC165_CK = 1;
- HC165_nPL = 0; //HC165读按键
- HC165_nPL = 1; //暂停HC165读按键
- Temp1 = 0;
- if(HC165_OUT == 1)
- {
- Temp1 |= 0x01;
- }
- for(i = 0;i < 7;i++)
- {
- HC165_CK = 0;
- HC165_CK = 1;
- Temp1 <<= 1;
- if(HC165_OUT == 1)
- {
- Temp1 |= 0x01;
- }
- }
- HC165_CK = 0;
- HC165_CK = 1;
- Temp2 = 0;
- if(HC165_OUT == 1)
- {
- Temp2 |= 0x01;
- }
- for(i = 0;i < 7;i++)
- {
- HC165_CK = 0;
- HC165_CK = 1;
- Temp2 <<= 1;
- if(HC165_OUT == 1)
- {
- Temp2 |= 0x01;
- }
- }
- HC165_CK = 0;
-
- Temp = (Temp2 << 8) + Temp1;
- return(Temp);
- }
- void main( )
- {
- uint16 num;
-
- while(1)
- {
- num = HC165( );
-
- switch(num)
- {
- case 0xfffe: P1 = 0xfe; P2 = 0xff; break;
- case 0xfffd: P1 = 0xfd; P2 = 0xff; break;
- case 0xfffb: P1 = 0xfb; P2 = 0xff; break;
- case 0xfff7: P1 = 0xf7; P2 = 0xff; break;
- case 0xffef: P1 = 0xef; P2 = 0xff; break;
- case 0xffdf: P1 = 0xdf; P2 = 0xff; break;
- case 0xffbf: P1 = 0xbf; P2 = 0xff; break;
- case 0xff7f: P1 = 0x7f; P2 = 0xff; break;
- case 0xfeff: P1 = 0xff; P2 = 0xfe; break;
- case 0xfdff: P1 = 0xff; P2 = 0xfd; break;
- case 0xfbff: P1 = 0xff; P2 = 0xfb; break;
- case 0xf7ff: P1 = 0xff; P2 = 0xf7; break;
- case 0xefff: P1 = 0xff; P2 = 0xef; break;
- case 0xdfff: P1 = 0xff; P2 = 0xdf; break;
- case 0xbfff: P1 = 0xff; P2 = 0xbf; break;
- case 0x7fff: P1 = 0xff; P2 = 0x7f; break;
- default: break;
- }
- }
- }
所有资料51hei提供下载:
74LS165按键.zip
(82.88 KB)
(下载次数: 59, 2020-3-18 14:01 上传)
下载积分: 黑币 -5