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功能：按下K1时D1亮，松开时D1灭，P3_1对应K1 ,  P2_0对应D1

#include <REGX52.H>void main()
{while(1) {if(P3_1 == 0) //按下K1{P2_0 = 0;}else{P2_0 = 1;}}}

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按下按钮和松开按钮时会有抖动，所以需要用延时函数来避免抖动造成的影响

 

功能：每按一次按钮，改变一次D1的状态

在这里如果一直按着按键就无法跳出while，就无法改变灯的状态

#include <REGX52.H>
#include <INTRINS.H>void Delay(unsigned int t)		//@11.0592MHz
{unsigned char i, j;while(t --){_nop_();i = 2;j = 199;do{while (--j);} while (--i);}
}void main()
{while(1){if(P3_1 == 0) //按下K1{Delay(20); //按下消抖while(P3_1 == 0); //按完松开才能执行下一步操作Delay(20); //松开消抖P2_0 = ~P2_0; //亮变灭，灭变亮}}}

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功能：用LED灯实现二进制，每按一次加1

#include <REGX52.H>
#include <INTRINS.H>void Delay(unsigned int t)		//@11.0592MHz
{unsigned char i, j;while(t --){_nop_();i = 2;j = 199;do{while (--j);} while (--i);}
}void main()
{unsigned char LedNum = 0; //刚好八位，存P2的状态while(1){if(P3_1 == 0){Delay(20);while(P3_1 == 0);Delay(20);LedNum ++;P2 = ~LedNum;}}
}

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 功能：每按一次，LED灯移动一位

#include <REGX52.H>
#include <INTRINS.H>void Delay(unsigned int t);unsigned char LedNum; //表示移动位数void main()
{while(1){if(P3_1 == 0) //按下K1{Delay(20);while(P3_1 == 0);Delay(20);LedNum ++;if(LedNum == 8) LedNum = 0;P2 = ~(0x01 << LedNum);}if(P3_0 == 0) //按下K2{Delay(20);while(P3_0 == 0);Delay(20);if(LedNum == 0) LedNum = 7;else LedNum --;P2 = ~(0x01 << LedNum);}}
}void Delay(unsigned int t)
{unsigned char i, j;while(t --){_nop_();i = 2;j = 199;do{while (--j);} while (--i);}
}