51单片机入门C语言程序

/* 按下4×4键盘任意一个键，记下数码管显示的值。复位单片机后数码管显示刚才显示的值 */ #include<reg51.h> sbit speaker=P3^7; /////////////////键盘 sbit v1=P2^0; sbit v2=P2^1; sbit v3=P2^2; sbit v4=P2^3; sbit h1=P2^4; sbit h2=P2^5; sbit h3=P2^6; sbit h4=P2^7; /////////////////显示 sbit shu1=P1^3;/*第1位数码管共阴端*/ sbit shu2=P1^2;/*第2位数码管共阴端*/ sbit shu3=P1^1;/*第3位数码管共阴端*/ sbit shu4=P1^0;/*第4位数码管共阴端*/ ////////////////24c02 sbit sda=P3^4; sbit scl=P3^2; void start(); void delay1(); unsigned int read(unsigned int word_address); void write(unsigned int word_address,da); void delayms(unsigned int i); unsigned char yima[]={0xeb,0x88,0xb3,0xba,0xd8,0x7a,0x7b,0xa8,0xfb,0xfa};/*译码表，此表数据和硬件相关*/ unsigned int b=0;/*要显示的数据*/ unsigned int b_count=0;/*扫描次数*/ void delayms(unsigned int i); unsigned char keyboar(); void t0()interrupt 1 using 1 /*中断程序负责显示b的值 */ { unsigned char a1=0,a2=0,a3=0,a4=0; static int k=0; /*数码管扫描显示*/ a1=b/1000;/*取b的千位*/ a2=b%1000/100;/*取b的百位*/ a3=b%100/10;/*取b的十位*/ a4=b%10;/*取b的个位*/ if(k==0){shu4=1;shu1=0;shu2=0;shu3=0;P0=yima[a1];} else if(k==1){shu4=0;shu1=1;shu2=0;shu3=0;P0=yima[a4];} else if(k==2){shu4=0;shu1=0;shu2=1;shu3=0;P0=yima[a3];} else if(k==3){shu4=0;shu1=0;shu2=0;shu3=1;P0=yima[a2];} k++; if(k>3)k=0; TH0=240; } main() { //write(1,60); unsigned char b_tem; b=read(1); speaker=0;/*关闭蜂鸣器电源，否则蜂鸣器会发热*/ EA=1;/*开全局中断 */ TR0=1;/*定时器0开始计数 */ ET0=1;/*定时器0开中断 */ TMOD=0X01;/*定时器0工作在方式1：16位计数模式 */ while(0) { } while(1) { b_tem=keyboar();/*把按键的代表的值给b */ if(b_tem<17) { if(b!=b_tem) { delayms(30); b=b_tem; write(1,b);/*把b的值写到24c02的地址为1的空间 */ } } } } void delayms(unsigned int i) { unsigned int j; for(;i>0;i--) for(j=100;j>0;j--); } unsigned char keyboar()/*线反转法 */ { static unsigned int a=0; unsigned char a1=0,b1=0; /*行线为输入线，列线为输出线 */ v1=v2=v3=v4=0; h1=h2=h3=h4=1; if(P2<0xf0)/*检查行是否有按键按下 */ { delayms(10); if(P2<0xf0) { /*行线为输入线，列线为输出线 */ v1=v2=v3=v4=0; h1=h2=h3=h4=1; a1=P2; /*行线为输出线，列线为输入线 */ h1=h2=h3=h4=0; v1=v2=v3=v4=1; b1=P2; a=a1|b1; /*与0x03相或是为了屏蔽p2.0和p2.1的影响*/ } } if (a==0xe7){return 7;}//chu else if(a==0xeb){return 8;} else if(a==0xed){return 9;} else if(a==0xee){return 13;} else if(a==0xd7){return 4;}// else if(a==0xdb){return 5;} else if(a==0xdd){return 6;} else if(a==0xde){return 12;} else if(a==0xb7){return 1;}//- else if(a==0xbb){return 2;} else if(a==0xbd){return 3;} else if(a==0xbe){return 11;} else if(a==0x77){return 0;}//+ else if(a==0x7b){return 15;} else if(a==0x7d){return 16;} else if(a==0x7e){return 10;} else return 17;//cuo wu } unsigned int read(unsigned int word_address) {unsigned int i=0,m=0,j=0,k=0,read_d=0xa1,write=0xa0,b=0,da2=0; bit a=1,c=0; start(); j=0; while(1)//device address { k=(write<<j)&0x80;j++; if(k>1)b=1; else b=0; sda=b; delay1(); scl=1; delay1(); scl=0; delay1(); sda=1; if(sda==0)break; } //sda=1;//check ack //a=sda; scl=1; delay1(); scl=0; j=0; while(1)//word address { k=(word_address<<j)&0x80;j++; if(k>1)b=1; else b=0; sda=b; delay1(); scl=1; delay1(); scl=0; delay1(); sda=1; if(sda==0)break; } //sda=1;//check ack //a=sda; scl=1; delay1(); scl=0; start(); j=0; for(i=0;i<8;i++) { k=(read_d<<j)&0x80; if(k>1)b=1; else b=0; sda=b; delay1(); scl=1; delay1(); scl=0; j++; } // sda=1;//check ack //read_d data for(i=0;i<8;i++) { scl=1; delay1(); scl=0; b=sda; b=b<<7; da2=(da2>>1)|b; } sda=1; delay1(); scl=1; delay1(); sda=0; // scl=0; return da2; } void write(unsigned int word_address,da) { unsigned int i=0,m=0,j=0,k=0,//word_addr=0x00, read_d=0xa1,write=0xa0; bit b=0; bit a=1,c=0; start(); while(1)//device address { k=(write<<j)&0x80; if(k>1)b=1; else b=0; sda=b; delay1(); scl=1; delay1(); scl=0; delay1(); sda=1; if(sda==0)break; j++; } sda=1;//check ack while(sda==0)break; a=sda; // j=0; scl=1; delay1(); scl=0; while(sda==1)break; j=0; while(1)//word address { k=(word_address<<j)&0x80; if(k>1)b=1; else b=0; sda=b; delay1(); scl=1; delay1(); scl=0; delay1(); sda=1; if(sda==0)break; delay1(); j++; } sda=1;//check ack while(sda==0)break; a=sda; // j=0; scl=1; delay1(); scl=0; while(sda==1)break; for(i=0;i<8;i++)//write data { c=(da>>i)&0x01; sda=c; delay1(); scl=1; delay1(); scl=0; } sda=1;//check ack a=sda; while(sda==0)break;//check ack; scl=1; delay1(); scl=0; a=sda; delay1(); sda=0; delay1(); scl=1; delay1(); sda=1; a=sda;//stop write delay1(); scl=0; delay1(); } void delay1() {unsigned int i=100; for(;i>0;i--); } void start() { scl=1; scl=0; sda=1; scl=1; sda=0; scl=0; }