1：獨(dú)立按鍵控制小燈亮滅（單片機(jī)）：#include<reg52.h> //51單片機(jī)函數(shù)頭文件sbitkey=P3^0; //定義按鍵的IO口sbitD1=P1^0; //定義led燈的IO口voiddelay(unsignedchary) //延時(shí)子函數(shù){ unsignedcharj,k; for(j=y;j>0;j--) for(k=0;k<57;k--);}voidkeyscan(){ if(key==0) { delay(10); //延時(shí)10ms，去抖動(dòng) if(key==0) { D1=0; } }}voidmain(){ while(1) { keyscan(); }}2：矩陣鍵盤控制多個(gè)小燈（單片機(jī)）：#include<reg52.h>#defineuintunsignedint#defineucharunsignedcharsbitD1=P1^0;sbitD2=P1^1;sbitD3=P1^2;sbitD4=P1^3;voiddelay(uintz) //延時(shí)函數(shù){uintx,y;for(x=z;x>0;x--)for(y=100;y>0;y--); }voidmain(){while(1){ uchartemp; P3=0xfe; //鍵盤掃描temp=P3;temp=temp&0xf0;while(temp!=0xf0) { delay(5); //延時(shí)去抖temp=P3;temp=temp&0xf0;while(temp!=0xf0) {temp=P3;switch(temp){case0xee:D1=0;break;case0xde:D2=0;break; }} while(temp!=0xf0) //按鍵松手檢測(cè) { temp=P3; temp=temp&0xf0; } } P3=0xfd;temp=P3;temp=temp&0xf0;while(temp!=0xf0) {delay(5);temp=P3;temp=temp&0xf0;while(temp!=0xf0) {temp=P3;switch(temp){ case0xde:D3=0;break; case0xdd:D4=0;break; }} while(temp!=0xf0) { temp=P3; temp=temp&0xf0; } }}}3：矩陣鍵盤控制數(shù)碼管顯示（單片機(jī)）：#include<reg52.h>#defineuintunsignedint#defineucharunsignedcharsbitwela=P2^0;ucharcodetable[]={ //段選的數(shù)字決定顯示的數(shù)字，這里的是數(shù)字0~150x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f,0x77,0x7c,0x39,0x5e,0x79,0x71,};voiddelay(uintz) //延時(shí)ms函數(shù){uintx,y;for(x=z;x>0;x--)for(y=110;y>0;y--); }voiddisplay(ucharnum) //顯示子函數(shù){ P0=table[num];}voidmain(){ uchartemp,num; //初始化位選，顯示0 P0=0x3f; wela=0; while(1) { P3=0xfe; //按鍵檢測(cè) temp=P3; temp=temp&0xf0; while(temp!=0xf0) { delay(5); temp=P3; temp=temp&0xf0; while(temp!=0xf0) { temp=P3; switch(temp) { case0xee:num=0; break; case0xde:num=1; break; } } while(temp!=0xf0) //按鍵松手檢測(cè) { temp=P3; temp=temp&0xf0; } } display(num); P3=0xfd; //按鍵檢測(cè) temp=P3; temp=temp&0xf0; while(temp!=0xf0) { delay(5); temp=P3; temp=temp&0xf0; while(temp!=0xf0) { temp=P3; switch(temp) { case0xde:num=2; break; case0xdd:num=3; break;