Analysis of the problems of the 11th Blue Bridge Cup single chip microcomputer provincial competition

Recently, I have just finished writing the title of the 11th session , Let's see 2020 The title of the provincial competition in .

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The topic is still LED、 Nixie tube 、 Key three modules  , And analog voltage input （ADC）、AT24C02（EEPROM）, Are common peripherals , And the question appeared before , So it's not hard , All the tests are basic skills .

1 The nixie tube shows

The nixie tube mainly displays the obtained voltage 、 There are three interfaces for counting and parameter setting , However, pay attention to the voltage data interface after power on .

2 LED

When the voltage is less than the set parameter 5s after L1 bright , This is still very easy to do . When the count is odd L2 bright , If you count , I first judge whether the voltage is larger or smaller than the parameter, and then judge whether the voltage is larger or smaller than the parameter after a period of time , If the results of the two comparisons are different, there is an intersection between the voltage and the parameters . Define a variable count, Every time the wrong key is pressed count++, When count>=3 when L3 bright , The right key makes count=0.

3 Key module

This time I use a matrix keyboard, which is different from the previous one .s12 It's the voltage 、 Switch between the three interfaces of counting and parameter setting ,s13 It is a key that can reset the count ,s16,s17 It's an addition and subtraction button, but please note that the range is [0,5].

4 ADC

Is to rewrite the underlying driver code （IIC）.

5 EEPROM

Is to rewrite the underlying driver code （IIC）, Pay attention to adding and subtracting parameters *10 Save to after EEPROM in , So after adding and subtracting, you can directly /10.0 such *10 It is also the original value , In addition, the specified storage address is 0.

IIC.c

#include"IIC.h"

#define DELAY_TIME 5

#define SlaveAddrW 0xA0
#define SlaveAddrR 0xA1

sbit SDA = P2^1; 
sbit SCL = P2^0; 

void IIC_Delay(unsigned char i)
{
    do{_nop_();}
    while(i--);        
}

void IIC_Start(void)
{
    SDA = 1;
    SCL = 1;
    IIC_Delay(DELAY_TIME);
    SDA = 0;
    IIC_Delay(DELAY_TIME);
    SCL = 0;	
}

void IIC_Stop(void)
{
    SDA = 0;
    SCL = 1;
    IIC_Delay(DELAY_TIME);
    SDA = 1;
    IIC_Delay(DELAY_TIME);
}

bit IIC_WaitAck(void)
{
    bit ackbit;
	
    SCL  = 1;
    IIC_Delay(DELAY_TIME);
    ackbit = SDA;
    SCL = 0;
    IIC_Delay(DELAY_TIME);
    return ackbit;
}

void IIC_SendByte(unsigned char byt)
{
    unsigned char i;

    for(i=0; i<8; i++)
    {
        SCL  = 0;
        IIC_Delay(DELAY_TIME);
        if(byt & 0x80) SDA  = 1;
        else SDA  = 0;
        IIC_Delay(DELAY_TIME);
        SCL = 1;
        byt <<= 1;
        IIC_Delay(DELAY_TIME);
    }
    SCL  = 0;  
}

unsigned char IIC_RecByte(void)
{
    unsigned char i, da;
    for(i=0; i<8; i++)
    {   
    	SCL = 1;
	IIC_Delay(DELAY_TIME);
	da <<= 1;
	if(SDA) da |= 1;
	SCL = 0;
	IIC_Delay(DELAY_TIME);
    }
    return da;    
}

unsigned char Read_AD()
{
	unsigned char temp;
	
	IIC_Start();
	IIC_SendByte(0x90);
	IIC_WaitAck();
	
	IIC_SendByte(0x03);
	IIC_WaitAck();
	IIC_Stop();
	
	IIC_Start();
	IIC_SendByte(0x91);
	IIC_WaitAck();
	temp=IIC_RecByte();
	IIC_Stop();
	
	return temp;
}

void write_eeprom(unsigned char add,unsigned char da)
{
	IIC_Start();
	IIC_SendByte(0xa0);
	IIC_WaitAck();
	
	IIC_SendByte(add);
	IIC_WaitAck();
	
  IIC_SendByte(da);
	IIC_WaitAck();
	
	IIC_Stop();
}

unsigned char Read_eeprom(unsigned char add)
{
	unsigned char da;
	IIC_Start();
	IIC_SendByte(0xa0);
	IIC_WaitAck();
	IIC_SendByte(add);
	IIC_WaitAck();
	IIC_Stop();
	
	IIC_Start();
  IIC_SendByte(0xa1);
	IIC_WaitAck();
	da=IIC_RecByte();
	IIC_Stop();
	return da;
}

IIC.h

#ifndef _IIC_H_
#define _IIC_H_

#include<stc15f2k60s2.h>
#include<intrins.h>

void IIC_Delay(unsigned char i);
void IIC_Start(void);
void IIC_Stop(void);
bit IIC_WaitAck(void);
void IIC_SendByte(unsigned char byt);
unsigned char IIC_RecByte(void);
unsigned char Read_AD();
void write_eeprom(unsigned char add,unsigned char da);
unsigned char Read_eeprom(unsigned char add);

#endif

init.c

#include"init.h"

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

extern u8 mode;
static u8 segaddr=0,key_press,key_state,key_num=0,row;
u8 value=0;
u8 code tab[]={0xc0,0xf9,0xa4,0xb0,0x99,0x92,0x82,0xf8,0x80,0x90,0xbf,0xff,0xc1,0x8c,0xc8};
u8 seg[]={11,11,11,11,11,11,11,11};

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;P0=0xff;P2&=0x1f;
	
	P2=(P2&0x1f)|0xc0;P0=1<<segaddr;P2&=0x1f;
	
	if((mode==1||mode==2)&&segaddr==5)     // Judge whether to use decimal point 
	{
		P2=(P2&0x1f)|0xe0;P0=tab[seg[segaddr]]&0x7f;P2&=0x1f;
	}
	else
	{
		P2=(P2&0x1f)|0xe0;P0=tab[seg[segaddr]];P2&=0x1f;
	}
	
	if(++segaddr==8)segaddr=0;
}

u8 Read_key()    // Matrix keyboard （ State machine ）
{
	switch(key_state)
	{
		case state_0:
			key_io=0x0f; P42=0; P44=0;
			key_press =key_io;
            
			if(key_press != 0x0f)
				key_state = state_1;
			break;
		case state_1:
			key_press =key_io;
			if(key_press != 0x0f)
			{
				if((key_io&0x08)==0)  row=4;
				if((key_io&0x04)==0)  row=5;
				if((key_io&0x02)==0)  row=6;
				if((key_io&0x01)==0)  row=7;
				
				key_io=0xf0; P42=1;P44=1; 
				if(P44==0) key_num=row;
				if(P42==0) key_num=row+4;
				if((key_io&0x20)==0) key_num=row+8;
				if((key_io&0x10)==0) key_num=row+12;		
				key_state = state_2;
			}
			else
				key_state = state_0;
			break;
		case state_2:
			key_io=0x0f; P42=0; P44=0;
			key_press =key_io;
			if(key_press == 0x0f)	key_state = state_0;
			break;
	}
	value=key_num;
	key_num=0;
	return value;
}

void Timer0Init(void)		
{
	AUXR |= 0x80;		
	TMOD &= 0xF0;		
	TL0 = 0xCD;		
	TH0 = 0xD4;		
	TF0 = 0;		
	TR0 = 1;	
  EA = 1;
  ET0 = 1;	
}

init.h

#ifndef _INIT_H_
#define _INIT_H_

#include<stc15f2k60s2.h>

void all_init();
void display();
unsigned char Read_key();
void Timer0Init(void);		

#endif

jm.c

#include"jm.h"
#include"IIC.h"

#define u8 unsigned char
#define u16 unsigned int
	
extern u8 mode,seg[],N,Y;         // extern Indicates that this variable is defined elsewhere , To quote... Here 
extern u16 RB2;
extern float V;
	
void Delay5ms()		
{
	unsigned char i, j;

	i = 54;
	j = 199;
	do
	{
		while (--j);
	} while (--i);
}

void jm12()
{
	if(mode==1)    // Voltage display interface 
	{
		seg[0]=12;
		seg[1]=11;
		seg[2]=11;
		seg[3]=11;
		seg[4]=11;
		seg[5]=RB2/100;
		seg[6]=RB2/10%10;
		seg[7]=RB2%10;
	}
	if(mode==2)    // Parameter display interface 
	{
		seg[0]=13;
		seg[1]=11;
		seg[2]=11;
		seg[3]=11;
		seg[4]=11;
		seg[5]=Y/10;
		seg[6]=Y%10;
		seg[7]=0;
	}
	if(mode==3)     // Counting display interface 
	{
		seg[0]=14;
		seg[1]=11;
		seg[2]=11;
		seg[3]=11;
		seg[4]=11;
		seg[5]=11;
		seg[6]=N/10;
		seg[7]=N%10;
	}
}

void jm13()      // Count reset interface 
{
	if(mode==3)  
		N=0;
}

void jm16()    
{
  if(mode==2)
  {
	Y+=5;
	if(Y>=50)Y=0;
	V=Y/10.0;
  }
	write_eeprom(0x00,V*10);
	Delay5ms();
}

void jm17()
{
  if(mode==2)
  {
	Y-=5;
	if(Y<=0)Y=50;
	V=Y/10.0;
  }
	write_eeprom(0x00,V*10);
	Delay5ms();
}

jm.h

#ifndef _JM_H_
#define _JM_H_

#include<stc15f2k60s2.h>

void jm12();
void jm13();
void jm16();
void jm17();
void Delay5ms();

#endif

main.c

#include"init.h"
#include"IIC.h"
#include"jm.h"

#define u8 unsigned char
#define u16 unsigned int
	
u8 num=0,mode=1,N=0,Y=30,count=0,e_count=0,high=0,low=0;
u16 RB2_count=0,RB2=0,L1_count=0,cp_count=0;
bit RB2_flag=0,L1_flag=0,e_flag=0,cp_flag=0,L1=0;
extern u8 seg[];
float V;

void LED();

void main()
{
	all_init();
	Timer0Init();
	while(1)
	{
		num=Read_key();
		switch(num)
		{
			case 12:
				if(++mode==4)mode=1;
				break;
			case 13:
				if(mode==3)     // Determine whether the key is correct 
				{
					jm13();
					count=0;
				}
			  else count++;
				break;
			case 16:
				if(mode==2)          // Determine whether the key is correct 
				{
					jm16();
					count=0;
				}
			  else count++;
				break;
			case 17:
				if(mode==2)      // Determine whether the key is correct 
				{
					jm17();
					count=0;
				}
			  else count++;
				break;
		}
		jm12();
		LED();
		if(Y*10>=RB2)     // Compare the voltage and parameters for the first time 
			high=1;
		else if(Y*10<=RB2)
			low=1;
		if(cp_flag==1)       //500ms Judge the voltage and parameters for the second time 
		{
			cp_flag=0;
			if(high+low==2)
			{
				N++;
				high=0,low=0;
			}
			else
				high=0,low=0;
		}
		if(RB2_flag==1)
		{
			RB2_flag=0;
			RB2=Read_AD();
			RB2=(RB2*100)/51.0+0.5;
		}
		if(RB2<Y*10)L1_flag=1;   // Judge L1 Whether it is on 
		else 
		{
			L1_flag=0;
			L1=0;
		}
		if(e_flag==1)
		{
			e_flag=0;
			V=Read_eeprom(0x00);
	        Y=V;
		}
	}
}

void LED()
{
	u8 i=0xff;
		if(L1==1)
		{
			P2=(P2&0x1f)|0x80;P0=i&0xfe;P2&=0x1f;
		}
		else
		{
			P2=(P2&0x1f)|0x80;P0=i|0x01;P2&=0x1f;
		}
		if(N%2!=0)
		{
			P2=(P2&0x1f)|0x80;P0=i&0xfd;P2&=0x1f;
		}
		else
		{
			P2=(P2&0x1f)|0x80;P0=i|0x02;P2&=0x1f;
		}
		if(count>=3)
		{
			P2=(P2&0x1f)|0x80;P0=i&0xfb;P2&=0x1f;
		}
		else
		{
			P2=(P2&0x1f)|0x80;P0=i|0x04;P2&=0x1f;
		}
}

void Timer0() interrupt 1
{
	display();
	if(++RB2_count==100)
	{
		RB2_count=0;
		RB2_flag=1;
	}
	if(L1_flag==1)
	{
		L1_count++;
		if(L1_count==5000)
		{
			L1_count=0;
			L1=1;
		}
	}
	if(++e_count==200)
	{
		e_count=0;
		e_flag=1;
	}	
	if(high==1||low==1)
	{
		if(++cp_count==500)
		{
			cp_count=0;
			cp_flag=1;
		}
	}
}