[嵌入式]第十届蓝桥杯单片机组（省赛）——试题解答

随着距离蓝桥杯举办日期的日益临近，今天才真正完成了第一套真题，基本就考察了几个外设的使用，已经按键和各个外设之间的灵活使用。总的来说第十届蓝桥杯省赛题目不是很难，下面是我的代码，如果有什么问题大家可以积极沟通，一起进步鸭。

# include "reg52.h"
 # include "iic.h"
 sbit S4 = P3^3;
 sbit S5 = P3^2;
 sbit S6 = P3^1;
 sbit S7 = P3^0;
unsigned char sin_S5 = 0;
unsigned char sin_S6 = 0;
unsigned char sin_S7 = 0;
int dataint_RB2 ;
 unsigned char a = 1;
 unsigned t_cout = 0;
 unsigned f_cout = 0;
 unsigned c_cout = 0;
 unsigned char data_RB2 = 0; 
 unsigned char  SMG_NoDot[12]={0xc0,0xf9,
	  0xa4,0xb0,0x99,0x92,0x82,0xf8,0x80,0x90,
    0xbf,0x7f};

 unsigned char  SMG_Dot[10]={0x40,0x79,
	  0x24,0x30,0x19,0x12,0x02,0x78,0x00,0x10,
    };

void SMG_delay(unsigned t)
 {
 	while(t--);
 }

 void select_HC138(unsigned char n)
 {
 	switch(n){
 	case 4:	
			P2 = (P2&0x1f)|0x80;  //led 
		break;
	case 5:
			P2 = (P2&0x1f)|0xa0;  // 外设
		break;
 	case 6:
			P2 = (P2&0x1f)|0xc0; // 数码管	位选 
		break;
	case 7:
			P2 = (P2&0x1f)|0xe0; // 数码管
		break;
	case 0 :
			P2 = P2&0x1f  ;
			}
 }

 void system_init()
 {
 	select_HC138(4);
	P0 = 0xff;
 	select_HC138(5);
	P0 = 0x00;
 	select_HC138(7);
	P0 = 0xff;	
	select_HC138(0);			
 
 }

 void SMG_show(unsigned char value , unsigned char pos)
 {
 	 P0 = 0xff;
	 select_HC138(6);
	 P0 = 0x01<< pos;
	 select_HC138(7);
	 P0 = value;
 
 }
 void RB2_show()
 {
   	if (sin_S7){
	select_HC138(6);
	P0 = 0x00;
	select_HC138(7);
	P0 = 0xff;
	select_HC138(0);
	} 
	else{
 	IIC_Start();
	IIC_SendByte(0x90); // 1001 0000
	IIC_WaitAck();
	IIC_SendByte(0x03);	  
 	IIC_WaitAck();
	IIC_Stop();

    IIC_Start();
	IIC_SendByte(0x91);
	IIC_WaitAck();	
 	data_RB2 = IIC_RecByte();
 	IIC_SendAck(1);
	IIC_Stop();
	dataint_RB2 = (int)data_RB2;
 	dataint_RB2 = 	(float)dataint_RB2*500/255;

	SMG_show(0xc1,0);
	SMG_delay(500);
	SMG_show(0xff,1);
	SMG_delay(500);
	SMG_show(0xff,2);
	SMG_delay(500);
	SMG_show(0xff,3);
	SMG_delay(500);
	SMG_show(0xff,4);
	SMG_delay(500);
	if(sin_S5){
		SMG_show(SMG_Dot[2],5);
		SMG_delay(500);
		SMG_show(SMG_NoDot[0],6);
		SMG_delay(500);
		SMG_show(SMG_NoDot[0],7);
		SMG_delay(500);
 }
 	else{
	SMG_show(SMG_Dot[dataint_RB2/100],5);
	SMG_delay(500);
	SMG_show(SMG_NoDot[(dataint_RB2%100)/10],6);
	SMG_delay(500);
	SMG_show(SMG_NoDot[dataint_RB2%10],7);
	SMG_delay(500);}  }
 }
 void Time_init() //定时器0计数，定时器1计时
 {
 	TH0 = 0xff;
	TH0 = 0xff;
   	TMOD = 0x16;
	TL1 = 0xB0;		//设置定时初始值
	TH1 = 0x3C;		//设置定时初始值

	ET0 = 1;
	ET1 = 1;
	EA = 1;
	TR1 = 1;		//定时器1开始计时
	TR0 = 1;		//定时器1开始计时
 }
void time0_server()interrupt 1
{
	c_cout ++ ; 
 }
void time1_server()interrupt 3
{
   	TL1 = 0xB0;		//设置定时初始值
	TH1 = 0x3C;		//设置定时初始值
	t_cout ++;
	if (t_cout == 20){
	 f_cout = c_cout;
	 t_cout = 0;
	 c_cout = 0;
	}
}
void  fre_show()

{	if (sin_S7){
	select_HC138(6);
	P0 = 0x00;
	select_HC138(7);
	P0 = 0xff;
	select_HC138(0);
	} 
	else{
	SMG_show(0x8e,0);
	SMG_delay(500);
	SMG_show(0xff,1);
	SMG_delay(500);
	SMG_show(0xff,2);
	SMG_delay(500);
	if(f_cout>9999)
		{SMG_show(SMG_NoDot[f_cout/10000],3);
		SMG_delay(500);}
	if(f_cout>999)
		{SMG_show(SMG_NoDot[(f_cout/1000)%10],4);
		SMG_delay(500);}
	if(f_cout>99)
		{SMG_show(SMG_NoDot[(f_cout/100)%10],5);
		SMG_delay(500);}
	if(f_cout>9)
		{SMG_show(SMG_NoDot[(f_cout/10)%10],6);
		SMG_delay(500);}
	SMG_show(SMG_NoDot[f_cout%10],7);
		SMG_delay(500);
   }
}

void led_cor()

{
	if (sin_S6){
	select_HC138(4);
	P0 = 0xff;
	select_HC138(0);
	} 
	else{
	P0 = 0xff;
	if(a==1){
	select_HC138(4);
	P0 = (P0&0xfc)|0x02;
	 
	 }
	else {
	select_HC138(4);
	P0 = (P0&0xfc)|0x01;
	
	}
	if(f_cout<1000) P0 = (P0&0xf7)|0x08;
	else if((f_cout<5000)&&(f_cout>=1000))P0 = (P0&0xf7)|0x00;
	else if((f_cout<10000)&&(f_cout>=5000)) P0=(P0&0xf7)|0x08;
	else if(f_cout>=100000)  P0 = (P0&0xf7)|0x00;

	if(dataint_RB2<150) P0 = (P0&0xfb)|0x04;
	else if((dataint_RB2<250)&&(dataint_RB2>=150))P0 = (P0&0xfb)|0x00;
	else if((dataint_RB2<350)&&(dataint_RB2>=250)) P0=(P0&0xfb)|0x04;
	else if(dataint_RB2>=350)  P0 = (P0&0xfb)|0x00;

	if(dataint_RB2 == 200) P0 = (P0&0xef)|0x10;
	else P0 =(P0&0xef)|0x00;

	select_HC138(0); }
}
void keyscan()
{	led_cor();
	if(a==1)RB2_show();
	else fre_show();
	if(S4==0){
	SMG_delay(2000);
		while(S4 == 0){
		if(a)RB2_show();
		else fre_show();
		}
	  if(a==1) a = 0;
	  else a =1;
	}
 	if(S5==0){
	SMG_delay(2000);
		while(S5 == 0){
		if(a)RB2_show();
		else fre_show();
		}
	  if(sin_S5==1) sin_S5 = 0;
	  else sin_S5 =1;
	}
	 	if(S6==0){
	SMG_delay(2000);
		while(S6 == 0){
		if(a)RB2_show();
		else fre_show();
		}
	  if(sin_S6==1) sin_S6 = 0;
	  else sin_S6 =1;
	}
	 	if(S7==0){
		SMG_delay(2000);
		while(S7 == 0){
		if(a)RB2_show();
		else fre_show();
		}
	  if(sin_S7==1) sin_S7 = 0;
	  else sin_S7 =1;
	}
}
 void main()
 {
   system_init();
   Time_init();
 	while(1)
		{ 
		  //RB2_show();
		  keyscan();
			}
 }