Analysis of the problems of the 7th Blue Bridge Cup single chip microcomputer provincial competition

Today brings you the seventh （2016） Analysis of the provincial competition topic , The topic is not difficult on the whole , Let's have a look .

  subject

  The overall problem of this provincial competition is not difficult , In addition to PWM It's not easy to understand , Others are easy to understand , The most important thing is the logic of programming . Topic investigated LED Show 、 Key 、 The nixie tube shows （ These three modules will be tested for each set of questions , We should be familiar with ）、PWM、DS18B20.

1 The nixie tube shows

There are two modes of nixie tube , One is the working mode , One is room temperature mode . We can write two interface functions , One is used to display the working mode , Another shows room temperature mode , Press the key to select which mode to display .

2 LED Show

Define a variable mode, Control by pressing the key mode The value of makes it in 1-3 In between .mode by 1 when L1 bright ,mode by 2 when L2 bright ,mode by 3 when L3 bright .

3 Key module

The title is used s4,s5,s6,s7 Four buttons , It's a stand-alone keyboard .s4 Used to control mode Value .s5 Used to control the countdown , Also define a countdown_mode Variable in 1-3 In between ,countdown_mode by 1 The countdown is 0,countdown_mode by 2 The countdown is 60,countdown_mode by 3 The countdown is 120.s6 Is to put countdown_mode Set to 1.s7 There are two states , Define a temp_m Variable to control , by 1 Display room temperature mode , by 0 Display the working mode .

4 pwm

because pwm The signal frequency of is 1KHz, Namely 1ms.P34 The pin has a connection timer 0, We use it 1ms Timer for 0 To control pwm Duty cycle of , For example, when pwm The duty cycle of is 20% when , You can use a timer 0 Control makes L1 bright 0.2ms, destroy 0.8ms To display pwm Duty cycle of . See code for details .

5 DS18B20

Is to rewrite the underlying driver code （onewire）, Then put it in the timer , Measure every once in a while .

onewire.c

#include"onewire.h"

#define u8 unsigned char
#define u16 unsigned int 

bit initflag;
sbit DQ=P1^4;

void Delay1us()		
{
	_nop_();
	_nop_();
	_nop_();
}

void delay_us(unsigned int us)
{
	while(us--)
	{
		Delay1us();
	}
}

bit init_ds18b20()
{
	
	DQ=0;
	delay_us(500);
	DQ=1;
	delay_us(20);
	initflag=DQ;
	delay_us(50);
	return initflag;
}

unsigned int get_temp()
{
	unsigned char low,high;
	unsigned int result;
	float i;
	
	init_ds18b20();//³õʼ»¯
	ds18b20_wirteByte(0xcc);
	ds18b20_wirteByte(0x44);
	
	init_ds18b20();
	ds18b20_wirteByte(0xcc);
	ds18b20_wirteByte(0xbe);
	
	low=ds18b20_readByte();
	high=ds18b20_readByte();
	
	result=high&0x0f;
	
	result<<=8;
	result=result|low;
	i=result*0.0625;
	result=i*100;
		return result;
	
}

void ds18b20_wirteByte(unsigned char dat)
{
	unsigned char i=0;
	for(i;i<8;i++)
	{
		DQ=0;
		DQ=dat&0x01;
		delay_us(65);
		DQ=1;
		dat=dat>>1;
		
	}
}

u8 ds18b20_readByte()
{
	unsigned char i=0;
	unsigned char dat;
	for (i;i<8;i++)
	{
		DQ=0;
		dat=dat>>1;
		DQ=1;
		if(DQ)
		{
			dat|=0x80;	
		}
		delay_us(15);
	}
	return dat;
}

onewire.h

#ifndef _ONEWIRE_H_
#define _ONEWIRE_H_


#define u8 unsigned char 
#define u16 unsigned int 
	
#include<STC15F2K60S2.h>
#include"intrins.h"


void Delay1us();
void delay_us(u16 us);
bit init_ds18b20();
u16 get_temp();
void ds18b20_wirteByte(u8 dat);
u8 ds18b20_readByte();



#endif

INIT.c

I like to initialize 、 Timer 、 The nixie tube shows 、 The keyboard is placed in a module .

#include"INIT.h"

#define u8 unsigned char 
#define u16 unsigned int 
#define state P3
#define state_0 0
#define state_1 1
#define state_2 2

u8 tab[]={0xc0,0xf9,0xa4,0xb0,0x99,0x92,0x82,0xf8,0x80,0x90,0xbf,0xff,0xc6};
u8 seg[]={11,11,11,11,11,11,11,11};

static  u8 key_state=0;
static  u8 segadder=0;

u8 row=0,key_press=0,key_num=0;

void all_init()  // Turn off irrelevant peripherals 
{
	P2=(P2&0x1f)|0x80;
	P0=0xff;
	P2&=0x1f;
	
	P2=(P2&0x1f)|0xa0;
	P04=0;
	P06=0;
	P2&=0x1f;
	
	P2=(P2&0x1f)|0xc0;
	P0=0x00;
	P2&=0x1f;
	
	P2=(P2&0x1f)|0xe0;
	P0=0xff;
	P2&=0x1f;
}

void display()    // Nixie tube display function 
{
	P2=(P2&0x1f)|0xe0;  // Blanking 
	P0=0xff;
	P2&=0x1f;
	
	P2=(P2&0x1f)|0xc0;   // Biting 
	P0=1<<segadder;
	P2&=0x1f;
	
	P2=(P2&0x1f)|0xe0;  // Segment selection 
	P0=tab[seg[segadder]];
	P2&=0x1f;
	
	if(++segadder==8)
		segadder=0;
}

u8 read_key()   // Independent keyboard 
{
	switch(key_state)
	{
		case state_0:
		state=0x0f;
		key_press=state;
		
		if(key_press!=0x0f)
			key_state=state_1;
		break;
		
		case state_1:
		key_press=state;	
		if(key_press!=0x0f)
		{
			if((key_press & 0x08)==0) row=4;
			if((key_press & 0x04)==0) row=5;
			if((key_press & 0x02)==0) row=6;
			if((key_press & 0x01)==0) row=7;
			key_state=state_2;
		}
		else
			key_state=state_0;
		break;
		
		case state_2:
		state=0x0f;
		key_press=state;
		if(key_press==0x0f)
			key_state=state_0;	
    break;		
	}
	key_num=row;
	row=0;
	return key_num;
}

void Timer0Init(void)		//100us
{
	AUXR |= 0x80;		
	TMOD &= 0xF0;		
	TL0 = 0xAE;		
	TH0 = 0xFB;		
	TF0 = 0;		
	TR0 = 1;		
	EA = 1;
}

void Timer1Init(void)		//1ms
{
	AUXR |= 0x40;		
	TMOD &= 0x0F;		
	TL1 = 0xCD;		
	TH1 = 0xD4;		
	TF1 = 0;		
	TR1 = 1;	
  ET1 = 1;
  EA = 1;	
}

INIT.h

#ifndef _INIT_H_
#define _INIT_H_


#define u8 unsigned char 
#define u16 unsigned int 
	
#include<STC15F2K60S2.h>
#include"intrins.h"


void all_init();
void display();
u8 read_key();
void Timer0Init(void);
void Timer1Init(void);






#endif

jm.c

This module is the function controlled by each key .

#include"jm.h"
#include"onewire.h"

#define u8 unsigned char 
#define u16 unsigned int

extern u8 seg[],countdown,moude,temp_flag; // extern Indicates that this variable is defined elsewhere , To quote... Here 

u16 temp;
	
void jm4()  //s4 Functions controlled 
{
	seg[0]=10;
	seg[1]=moude;
	seg[2]=10;
	seg[3]=11;
}

void jm5()  //s5 Functions controlled 
{
	seg[4]=countdown/1000;
	seg[5]=countdown/100%10;
	seg[6]=countdown/10%10;
	seg[7]=countdown%10;
}

void jm6()   //s6 Functions controlled 
{
	seg[4]=countdown/1000;
	seg[5]=countdown/100%10;
	seg[6]=countdown/10%10;
	seg[7]=countdown%10;
}

void jm7()   //s7 Functions controlled 
{
	if(temp_flag==1)
	{
		temp_flag=0;
    temp=get_temp();
	}
	seg[0]=10;
	seg[1]=4;
	seg[2]=10;
	seg[3]=11;
	seg[4]=11;
  seg[5]=temp/1000;
	seg[6]=temp/100%10;
	seg[7]=12;
}

jm.h

#ifndef _JM_H_
#define _JM_H_


#define u8 unsigned char 
#define u16 unsigned int 
	
#include<STC15F2K60S2.h>
#include"intrins.h"

void jm4();
void jm5();
void jm6();
void jm7();



#endif

main.c

#include"INIT.h"
#include"jm.h"
#include"onewire.h"

#define u8 unsigned char
#define u16 unsigned int

static u16 moude_count=0,pwm;
u8 num=0,moude=1,countdown=0,temp_m=0,countdown_moude=1;
u8 temp_flag=0;
u8 jma,jmb;
u16 countdown_count=0,temp_count=0;

extern seg[];

void main()
{
	all_init();
	Timer0Init();
	Timer1Init();
	while(1)
	{
		if(countdown>0) ET0 = 1;	// The countdown is greater than 0 Turn on timer 0				
		else ET0 = 0;		
		num=read_key();
		switch(num)
		{
			case 4:
			  if(++moude==4) moude=1;  // Three working modes 
			  if(moude==1) pwm=2;
			  if(moude==2) pwm=3;
			  if(moude==3) pwm=7;
			  jma=0,jmb=0;
				break;
			case 5:
              if(++countdown_moude==4) countdown_moude=1;   // Set the countdown 
			  if(countdown_moude==1) countdown=0;
			  if(countdown_moude==2) countdown=60;
			  if(countdown_moude==3) countdown=120;
			  jma=0,jmb=1;
				break;
			case 6:    // stop it , Zero clearing 
			  countdown=0;
			  jma=1,jmb=0;
				break;
			case 7:   // Working or room temperature interface 
				temp_m^=1;
			  if(temp_m==1)
				{
					jma=1,jmb=1;
				}
				else
				{
					jma=0,jmb=0;
				}
				break;
		}
		num=0;
		if(jma==0&&jmb==0) 
		{
			jm4();
			jm5();
		}
		if(jma==0&&jmb==1) jm5();	
	    if(jma==1&&jmb==0) jm6();
		if(jma==1&&jmb==1) jm7();
	}
}


void Timer1() interrupt 3
{
	display();
	countdown_count++;
	temp_count++;
	
	if(countdown_count==1000)    // Every second counts down by one 
	{
		if(countdown>0) countdown--;	
		countdown_count=0;
	}
	
	if(temp_count==200)   // Every time 200ms Get the room temperature once 
	{
		temp_flag=1;
		temp_count=0;
	}
}

void Timer0() interrupt 1
{
  if(moude_count<pwm)      pwm The larger the duty cycle ,led The brighter the light .
    {
	  if(moude==1&&countdown!=0)
	    {
		  P2=(P2&0x1f)|0x80;P0=0xfe;P2&=0x1f;
	    }
	  if(moude==2&&countdown!=0)
	    {
		  P2=(P2&0x1f)|0x80;P0=0xfd;P2&=0x1f;
	    }
	  if(moude==3&&countdown!=0)
		{
		  P2=(P2&0x1f)|0x80;P0=0xfb;P2&=0x1f;
		}
    }
   else
	{
	   P2=(P2&0x1f)|0x80;P0=0xff;P2&=0x1f;	
	}
	if(++moude_count>=10) moude_count=0;
}

Last , This is my first time to write a blog , Where the writing is not good , I hope you will correct me . I will also write later , I plan to finish writing a question , Just discuss with you .