单片机20道复习题参考答案.doc

1.用P0 口驱动LED灯，要求循环左移，从右向左每次两个LED灯亮，程序重复执行。

【一个排线。

排1（PO-LED）］#include <reg52.h> DelaylOms(SO); (^include <intrins.h> LED = LED « 2; unsigned char a, b;void DelaylOms(unsigned int c); if (P0 == OxCO) for (;c>O;c-)main() { {{ LED = 0x03; for (b=38;b>0;b-) unsigned char LED; (LED = 0x03; ) for (a=130;a>0;a~);while (1) } ){ } }P0 = LED; void DelaylOm$(unsigned int c) }2.用P0 口驱动LED灯做左右跑马灯程序，先向左侧跑马，每次左移2位，初始时是2位LED灯亮，以后每次2个灯亮。

待4次过后，再向右侧跑马，每次右移1位，初始时是1位LED灯亮，以后每次1个灯亮，执行8次。

程序重复执行。

【一个排线。

排1 (PO-LED)】存include <reg52.h> LED = LED « 2;P0 = LED;} (ftinclude <intrins.h> unsigned char a, b;void DelaylOms(unsigned int c); 〃延时Delayl0ms(50); for (;c>0;c・・)10ms LED = 0x80;P0 = LED; (main。

for(i=0;i<7;i++) for (b=38;b>0;b-)( (Delayl0ms(50); ( unsigned char LED; LED = LED » l;P0 = LED; } for (a=130;a>0;a~);unsigned char i; //Oxfe = llll 1110 }LED = 0x03; Delayl0ms(50); }while (1)/LED = OxO3;PO = LED; }\P0= LED; }for(i=0;i<3;i*+) }{Delayl0ms(50); void DelaylOms(unsigned int c)flinclude <reg51.h>unsigned char Key_Scan()i = 0;include <intrins.h> whil eunsigned char keyValue = 0, i;(K3==0))sb it K2 = P1A 1; if (K1==O) K3 = P1A 2;DelaylOms(l);sb it K4 = P1A 3; DelaylOms(l); Adefi ne GPIO LED PO if (K1==O) voidmain(void)i = 0;if(K4==0)while((i<50) && (K1==O))unsigned char ledValue, keyNum; DelaylOms(l); ledValue = 0x01; DelaylOms(l)； if(K4==0)while (1)ifkeyValue = 4; keyNum = Key_Scan(); i = 0;if (keyNum == 1)while((i<50)&& (K4==0))ledVal ueif(K2==0)DelaylOms(l)； -CrorJIedValue,DelaylOms(l);ifkeyValue = 1; ledVal uei = 0;return keyValue;_crolJledValue 1);while((i<50)&& (K2==0))void DelaylOms(unsigned int c)else if (keyNum == 3)DelaylOms(l);unsigned char a, b; ledValue = Oxff;for(;c>O;c-)else if (keyNum == 4)for(b=38;b>0;b-)if3. 用按键选择LED 灯做左右移动实验，3个按钮，K1对应P1.0, K2对应P1.1, K3对应Pl.2, K1按下让LED 灯左移1位循环，K2按下让LED 灯右移1位循 环，K3按下，8个灯全亮。

【两个排线。

排1（PO-LED ）排2（P1-独立按键）】Ivoid DelaylOms(unsigned int c); unsigned char Key_Scan();if (K2==0)else if (keyNum == 2)keyValue = 2;unsigned char a, b; for (;c>0;c ・・) (for (b=38;b>0;b-) (for (a=130;a>0;a-);4. 单个静态数码管流动显示HELLO-LACo 【一个排线。

排1(PO-・JP3(右上角))】#lnclude<reg51.h>Wdefine GPIO_DIG PO void DelaylOms(unsigned int c); unsignedcharcodeDIG_CODE[10)={0x76,0x79,0x38,0x38,0x3f,0x4 0,0x38,0x77,0x39}; void main(void) (unsigned char i = 0;while(l)GPIO_DIG = ~DIG_CODE[i]; i++； if(i == 10){i = 0; }Delayl0ms(50);}}void Delayl0m$(unsigned int c)5. 8位动态数码管显示BAD-FOODo 【两个排线。

排1 (P0-LED)排2(P1-J16)ttinclude<reg51.h> #define GPIO_DIG P0 ^define GPIO.PLACE Plunsigned char code DIG_PLACE[8] = { 0xfe,0xfd,0xfb,0xf7,0xef,0xdf,0xbf,0x7f}; unsigned char code DIG_CODE[8] {0x7c,0x77,0x5e,0x40,0x7L0x3f,0x3f,0x5e}; unsigned char Display Data (8); void DigDisplayO; void main(void) (unsigned char i; for(i=0; i<8; i++)(DisplayData(i) = DIG_CODE(i];} while(l) (DigDisplayO;}}void DigDisplay()unsigned chari; unsigned int j; for(i=0; i<8; i++) (GPIO_PLACE = DIG_PLACE[i] GPIO_DIG = DisplayData[i]; j = 10;whlle(j-); GPIO_DIG = 0x00;}}void DigDisplayO (unsigned char i; unsigned int j; for(i=0;i<8;i++) (switch(i) {case(O):LSA=O;LSB=O;LSC=O; break; case(l):LSA=l;LSB=O;LSC=O; break; case(2):LSA=0;LSB=l;LSC=0; break; case(3):LSA=l;LSB=l;LSC=0; break; case(4):LSA=0;LSB=0;LSC=l; break; case(5):LSA=l;LSB=0;LSC=l; break; case(6):LSA=0;LSB=l;LSC=l; break; case(7):LSA=l;LSB=l;LSC=l; break;}GPIO_DIG=DisplayData[i]; j=10; while(j-); GPIO_DIG=OxOO;}}void KeyDown(void)(unsigned int a=0; GPIO_KEY=OxOf; if(GPIO_KEY!=OxOf) (DelaylOms(l);a=0;if(GPIO_KEY!=OxOf) {KeyState=l;GPIO_KEY=OXOF;6. 矩阵键盘，按键移位，按键8次，显示“8765ABCD”。

#include<reg51.h>^define GPIO_DIG PO WdefineGPIO_KEYPl sbit LSA=P2A 2; sbit LSB=P2A 3; Sbit LSC=P2A 4;unsigned char code DIG_CODE[17]=(0x5e,0x39,0x7c,0x00,0x77,0x6d,0x7d,0x00,0x07,0x 7f}；unsigned char Key Value; unsigned char KeyState; unsigned char DlsplayData[8]; void DelaylOms(unsigned int c); void KeyDownf); void DigDisplay(); void main(void) {KeyState=O; while(l) {KeyDown(); if(KeyState==l) (DisplayData[7]=DisplayData[6); Di$playData(6)=Di$playData(5); DisplayData[5]=DisplayData(4); DisplayData[4]=DisplayData[3]; DisplayData[3]=DisplayData[2]; DisplayData[2]=DisplayData[l); DisplayData[l]=DisplayData(O); DisplayData[Oj=DIG_CODE[KeyValue]; KeyState=O;)DigDisplay();switch(GPIO_KEY) {case(0X07):Key Va I u e=0; b rea k; case(0X0b):KevValue=4;break; case(OXOd)： KeyValue=8;break; ca$e(0X0e):KeyValue=12;break;}GPIO_KEY=OXFO; switch(GPIO_KEY) (ca$e(0X70):KeyValue=KeyValue+3;break; case(OXbO):KeyValue=KeyValue+2;break; case(OXdO): KeyValue=KeyValue+l ；break; case(OXeO):break;while((a<50)&&(GPIO_KEY!=0xf 。