单片机接口程序.doc

实验一：8255 #include reg51.h #include absacc.h #define PA XBYTE[0X7CFF] //0111 1100，A1A0=00时选中端口A #define PB XBYTE[0X7DFF] //0111 1101，A1A0=01时选中端口B #define com XBYTE[0X7FFF] //0111 1111 A1A0=11时选中控制寄存器，P2.7为0选中芯片 void main() { unsigned char a; com=0x90; //1001 0000设置8255的控制字格式 a=PA; PB=a; } 实验二：485 先发后收: #include reg51.h unsigned char a; unsigned char b; int n; sbit p=P1^0; void Delay(int n); void main() { TMOD=0X20; SCON=0X50; TH1=0Xfd; TL1=0Xfd; TR1=1; b=0xff; while(1) { p=1 ; b=b-0x01; SBUF=b; while(TI==0) {} TI=0; Delay(3000); p=0; while(RI==0) {} P2=SBUF; RI=0; Delay(3000); } } void Delay(int n)//延时程序 { while(n--) {} } 先收后发： #include reg51.h unsigned char a; unsigned char b; int n; sbit p=P1^0; void Delay(int n); void main() { TMOD=0X20; SCON=0X50; TH1=0Xfd; TL1=0Xfd; TR1=1; while(1) { p=0; while(RI==0) {} P2=SBUF; a=SBUF; RI=0; Delay(3000); p=1; b=0xff-a; SBUF=b; while(TI==0) {} TI=0; Delay(3000); }} void Delay(int n) //延时程序 { while(n--) {} } 实验三：232 #includereg51.h //中断法，波特率9.6k void main() { SCON=0x50; TMOD=0x20; PCON=0X80; TL1=0XFA; TH1=0XFA; TR1=1; EA=1; ES=1;} void intserl(void)interrupt 4 { unsigned char date; if(RI) {date=SBUF; P2=date; RI=0; SBUF=0x4c; } TI=0; } 查询法： #includereg51.h //查询法,波特率9.6k void main() { unsigned char date; SCON=0x50; TMOD=0x20; PCON=0X80; TL1=0XFA; TH1=0XFA; TR1=1; EA=1; ES=1; while(1) {P1=0x00; if(RI) {date=SBUF; P2=date; RI=0; P1=0x01; SBUF=P0; TI=0;} else while(!RI);} } 实验四：LED #includereg52.h #includeintrins.h #define uint unsigned int #define uchar unsigned char sbit clk1=P2^0; sbit ds=P2^1; sbit clk2=P2^2; sbit oe1=P2^7; sbit oe2=P2^6; uchar a; uchar tab1[]={0xfe,0xfd,0xfb,0xf7,0xef,0xdf,0xbf,0x7f}; //逐列有效（列低电平有效） uchar tab