蓝桥杯单片机省赛第七届

 

 

 难点:如何控制pwm；已知频率为1kHZ，所以周期为1ms，使用100us的定时器，定义一个变量来记录过了多少时间，若想输出20%，前八个为0让第八个置1第十个置0；

 main.c

#include <STC15F2K60S2.H>
#include <ONEWIRE.H>

void Timer2Init()		//1毫秒@12.000MHz
{
	AUXR &= 0xFB;		//定时器时钟12T模式
	T2L = 0x18;		//设置定时初值
	T2H = 0xFC;		//设置定时初值
	AUXR |= 0x10;		//定时器2开始计时
	IE2|=0X04;
	EA=1;
}

void Timer0Init()		//100微秒@12.000MHz
{
	AUXR &= 0x7F;		//定时器时钟12T模式
	TMOD &= 0xF0;		//设置定时器模式
	TL0 = 0x9C;		//设置定时初值
	TH0 = 0xFF;		//设置定时初值
	TF0 = 0;		//清除TF0标志
	TR0 = 1;		//定时器0开始计时
	ET0=1;
	EA=1;
}

void Device_ctrl(unsigned char p2date,unsigned char p0date)
{
		P0=p0date;
	  P2=P2&0X1F|p2date;
	  P2&=0X1F;
}

unsigned char mode_display[8];
unsigned char temp_display[8];
unsigned char smg_du[]={0x3F,0x06,0x5B,0x4F,0x66,0x6D,0x7D,0x07,0x7F,0x6F};
unsigned int  smg_count;
unsigned char display_mode;
unsigned char mode=1;
unsigned int  time;
unsigned int time_count;

unsigned int temp;
unsigned int temp_count;
void  temp_process()
{
		if(temp_count>100)
		{
			temp_count=0;
			
			temp=read_temp();
		}
}
void smg_show()
{
		unsigned char i;
	  Device_ctrl(0xc0,0);
	  if(display_mode==0)
		{
				Device_ctrl(0xe0,~mode_display[i]);
		}
	  else
		{
				Device_ctrl(0xe0,~temp_display[i]);
		}
	  Device_ctrl(0xc0,0x01<<i);
	  i=(i+1)%8;
}

void smg_process()
{
			if(smg_count>3)
			{
				smg_count=0;
				
				mode_display[0]=0x40;
				mode_display[2]=0x40;
				mode_display[3]=0x00;
				
				temp_display[0]=0x40;
				temp_display[1]=smg_du[4];
				temp_display[2]=0x40;
				temp_display[3]=0x00;
				temp_display[4]=0x00;
				temp_display[7]=0x39;
				
				if(display_mode==0)
				{
					mode_display[1]=smg_du[mode];
					
					mode_display[4]=smg_du[time/1000];
					mode_display[5]=smg_du[time/100%10];
					mode_display[6]=smg_du[time/10%10];
					mode_display[7]=smg_du[time%10];
				}
				else
				{
						temp_display[5]=smg_du[temp/10];
						temp_display[6]=smg_du[temp%10];
				}
			}
}

unsigned char Trig_btn;
unsigned char Cont_btn;
unsigned int  key_count;
void key_btn()
{
		unsigned char readdate=P3^0XFF;
	  Trig_btn=readdate&(Cont_btn^readdate);
	  Cont_btn=readdate;
}

void key_process()
{
		if(key_count>=5)
		{
				key_btn();
			  key_count=0;
			  
			  if(Trig_btn==0x08)//s4
				{
					if(display_mode==0)
					{
							mode++;
						  if(mode==4)
							{
								mode=1;
							}
					}
				}
				
				if(Trig_btn==0x04)//s5
				{
					if(display_mode==0)
					{
					  if(time<9939)
						{
							time=time+60;
						}
					}
				}
				
				if(Trig_btn==0x02)//s6
				{
						if(display_mode==0)
					{
							time=0;
					}
				}
				
				if(Trig_btn==0x01)//s7
				{
						display_mode++;
					  if(display_mode==2)
						{
							display_mode=0;
						}
				}
		}
}

unsigned int led_count;
void led_process()
{
	  if(led_count>5)
		{
			led_count=0;
				if(time)
			{
					if(mode==1)
					{
						Device_ctrl(0x80,~0x01);
					}
					else if(mode==2)
					{
					 Device_ctrl(0x80,~0x02);
					}
					else
					{
						Device_ctrl(0x80,~0x04);
					}
			}
			else
			{
				Device_ctrl(0x80,0xff);
			}
		}
		
}
void main()
{
	  Timer2Init();
	  Timer0Init();
	  Device_ctrl(0xa0,0x00);
		while(1)
		{
			smg_process();
			key_process();
			led_process();
			temp_process();
		}
}

unsigned int mode_count;
void timer0service() interrupt 1
{
		mode_count++;
	 
	  
	  if(mode==1)
		{
			if(mode_count==8)
			{P34=1;}
			if(mode_count==10)
			{P34=0;}
		}
		else if(mode==2)
		{
			if(mode_count==7)
			{P34=1;}
			if(mode_count==10)
			{P34=0;}
		}
		else 
		{
			if(mode_count==3)
			{P34=1;}
			if(mode_count==10)
			{P34=0;}
		}

}

void timer2service() interrupt 12
{
		smg_count++;
	  smg_show();
	  key_count++;
	  time_count++;
	  led_count++;
	  temp_count++;
	  if(time_count>=1000)
		{
			time_count=0;
			if(time)
			{
				time--;
			}
		}
	  
}

ONEWIRE.C

#include "onewire.h"

//单总线内部延时函数
void Delay_OneWire(unsigned int t)  
{
	t=t*12;
	while(t--);
}

//单总线写操作
void Write_DS18B20(unsigned char dat)
{
	unsigned char i;
	for(i=0;i<8;i++)
	{
		DQ = 0;
		DQ = dat&0x01;
		Delay_OneWire(5);
		DQ = 1;
		dat >>= 1;
	}
	Delay_OneWire(5);
}

//单总线读操作
unsigned char Read_DS18B20(void)
{
	unsigned char i;
	unsigned char dat;
  
	for(i=0;i<8;i++)
	{
		DQ = 0;
		dat >>= 1;
		DQ = 1;
		if(DQ)
		{
			dat |= 0x80;
		}	    
		Delay_OneWire(5);
	}
	return dat;
}

//DS18B20初始化
bit init_ds18b20(void)
{
  	bit initflag = 0;
  	
  	DQ = 1;
  	Delay_OneWire(12);
  	DQ = 0;
  	Delay_OneWire(80);
  	DQ = 1;
  	Delay_OneWire(10); 
    initflag = DQ;     
  	Delay_OneWire(5);
  
  	return initflag;
}

float read_temp()
{
		unsigned  char low,high;
	  float date;
	   
	  init_ds18b20();
		Write_DS18B20(0xcc);
		Write_DS18B20(0x44);
	
		init_ds18b20();
		Write_DS18B20(0xcc);
		Write_DS18B20(0xbe);
	 
	  low=Read_DS18B20();
	  high=Read_DS18B20();
	
	  date=(high<<8)|low;
	  date=date*0.0625;
	 
	  return date;
}

ONEWIRE.H

#ifndef __ONEWIRE_H
#define __ONEWIRE_H

#include <STC15F2K60S2.H>

sbit DQ = P1^4;  

float read_temp();  

#endif