MCU+ADC0832+MQ2 temperature and smoke alarm control

1. Actual photos
 

 

 

 


2. Schematic diagram and PCB diagram drawn by Altium Designer are as follows: (Project files can be downloaded in the 51hei attachment)
 

 

Components list:
1. AT89C52
2. 40P base
3. 8P base
4. 5MM LED*2 (red, green)
5. 3MM LED (yellow)
6. 12M crystal oscillator
7. 30P ceramic capacitor*2
8. 10uf electrolytic capacitor
9. 10K resistor*2
10. 1K resistor*5
11. 16P LCD base
12. 103 potentiometer*2
13. 9*15 multi-purpose board
14. ADC0832 chip
15. 1602 LCD
16. Button*5
17. Relay
18. Buzzer
19. MQ2
20. MQ2 base
21. DS18B20
22. 3P round hole female socket
23. 8550 transistor
24. 8050 transistor
25. Self-locking switch
26. DC power socket
27. Wire 
28. USB power cable


3 whole machine program

#include

#include

#include

#include "DS18B20.h"   

#define uint unsigned int

#define uchar unsigned char //macro definition

#define BEEP P3_4 //define buzzer

#define hujiao P1_3 

sbit BEEP=P3^4;

sbit hujiao=P1^3;

sbit RS=P2^5;

sbit RW=P2^6;

sbit EN=P2^7;

sbit led_h=P1^4;

sbit led_l=P1^5;

sbit JDQ=P2^0;

sbit ADCS = P3^7;

sbit ADCLK = P3^5;

sbit ADDI = P3^6;

sbit ADDO = P3^6;

bit shanshuo_st; // flashing interval flag

bit beep_st; //Buzzer interval flag

bit flag=0; //Emergency call flag

sbit DIAN = P2^5; // Decimal point

uint abc;

uchar x=4; //Counter

signed char m; //temperature value global variable

uchar n; //temperature value global variable

fly data disdata[5];

flying code LEDData[]={0x28,0xeb,0x32,0xa2,0xe1,0xa4,0x24,0xea,0x20,0xa0};

uchar code table[8]={0x0c,0x12,0x12,0x0c,0x00,0x00,0x00,0x00}; // Celsius temperature symbol

/*****Initialize timer 0*****/

void InitTimer(void)

{

TMOD=0x1;

TH0=0x4c;

TL0=0x00; //50ms (crystal oscillator 11.0592M)

}

/*****Timer 0 interrupt service routine*****/

void timer0(void) interrupt 1

{

TH0=0x4c;

TL0=0x00;

x++;

}

/********Read temperature*****/

void check_wendu(void)

{

uint a,b,c;

c=ReadTemperature()-5; //Get the temperature value and subtract the temperature drift error of DS18B20

a=c/100; //Calculate the ten-digit number

b=c/10-a*10; //Calculate the unit digit

m=c/10; //Calculate the integer

n=ca*100-b*10; //Calculate the decimal places

if(m<0){m=0;n=0;} //Set the upper limit of temperature display

if(m>99){m=99;n=9;} //Set the upper limit of temperature display    

}

/*****************************lcd1602 program******************************/

void delay1ms(uint ms) //delay 1 millisecond (not precise enough)

{  uint i,j;

   for(i=0;i    for(j=0;j<100;j++);

}

unsigned char rolmove(unsigned  char m)

{ 

  unsigned char   a,b,c,d,e,f,g,h;               

a=(m&0x01)<<7;

b=(m&0x02)<<5;

c=(m&0x04)<<3; 

d=(m&0x08)<<1;

e=(m&0x10)>>1;

f=(m&0x20)>>3;

g=(m&0x40)>>5;

h=(m&0x80)>>7;

m=a|b|c|d|e|f|g|h; 

return m;

}

void wr_com(uchar com)//write instruction//

{ delay1ms(1);

   RS=0;

   RW=0;

   EN=0;

   P0=rolmove(com);

   delay1ms(1);

   EN=1;

   delay1ms(1);

   EN=0;

}

void wr_dat(uchar dat)//write data//

{ delay1ms(1);;

   RS=1;

   RW=0;

   EN=0;

   P0=rolmove(dat);

   delay1ms(1);

   EN=1;

   delay1ms(1);

   EN=0;

}

void wr_new() //Write new character

{

flying i;

wr_com(0x40);

for(i=0;i<8;i++)

{

  wr_dat(table[i]);

}

}

void lcd_init() //initialization settings //

{ delay1ms(15);

wr_com(0x38);delay1ms(5);

wr_com(0x08);delay1ms(5);

wr_com(0x01);delay1ms(5);

  wr_com(0x06);delay1ms(5);

wr_com(0x0c);delay1ms(5);

wr_new();

wr_com(0x80);

    wr_dat('S');//A

wr_com(0x81);

    wr_dat('m');//:

   wr_com(0x82);

    wr_dat('o');

   wr_com(0x83);

    wr_dat('k');

wr_com(0x84);

    wr_dat('e');

   wr_com(0x85);

    wr_dat(':');

   wr_com(0x87);

    wr_dat('T');

wr_com(0x88);

    wr_dat('e');

   wr_com(0x89);

    wr_dat('m');

   wr_com(0x8a);

    wr_dat(':');

wr_com(0x8d);

    wr_dat('.');

wr_com(0x8f);

    wr_dat('C');

wr_com(0xc0);

    wr_dat('A');

wr_com(0xc1);

    wr_dat('l');

wr_com(0xc2);

    wr_dat('a');

   wr_com(0xc3);

    wr_dat('r');

wr_com(0xc4);

    wr_dat('m');

wr_com(0xc5);

    wr_dat(':');

wr_com(0xcb);

    wr_dat('-');

   wr_com(0xce);

    wr_dat('C');   

}

/*****************Display function********************************/

void disp()//temperature value display

{

     disdata[0]=m/10+0x30; //ten digits

     disdata[1]=m%10+0x30; //single digit

     disdata[2]=n+0x30; //decimal digits

     disdata[3]=abc+0x30; //smoke density

    wr_com(0x8b);

    wr_dat(disdata[0]);//display tens digit 

    wr_com(0x8c);

    wr_dat(disdata[1]); //Display the unit digit 

    wr_com(0x8e);

    wr_dat(disdata[2]); //Display decimal places

    wr_com(0x86);

    wr_dat(disdata[3]);

}

void baojing()

{

wr_com(0xc9);

    wr_dat(tab[0]+0x30);

wr_com(0xca);

    wr_dat(tab[1]+0x30); 

wr_com(0xcc);

    wr_dat(tab[2]+0x30);

wr_com(0xcd);

    wr_dat(tab[3]+0x30);

wr_com(0xc6);

    wr_dat(tab[4]+0x30);

}

/*****Alarm subroutine*****/

void Alarm()

{

if((m>=shangxian&&beep_st==1)||(melse if(abc>=nongdu&&beep_st==1) BEEP=1;

else BEEP=0;

if(m>=shangxian||melse if(abc>=nongdu) {led_h=0;led_l=1;JDQ=0;}

else {led_h=1;led_l=0;JDQ=1;}

if(x>=10){beep_st=~beep_st;x=0;}

}

void Alarm1()

{

led_h=0;

led_l=1;

if(x>=10){beep_st=~beep_st;x=0;}

if(beep_st==1)BEEP=1;

else BEEP=0;

led_h=0;

led_l=1;

JDQ=0;

}

uchar ADC0832 (bit mode, bit channel) //AD conversion, return result

{

uchar i,dat,ndat;

ADCS = 0; // pull down the CS terminal

_nop_();

_nop_();

ADDI = 1; //The first falling edge is high level

ADCLK = 1; // pull up the CLK terminal

_nop_();

_nop_();

ADCLK = 0; // Pull down the CLK end to form a falling edge 1

_nop_();

_nop_();

ADDI = mode; //Low level is differential mode, high level is single channel mode. 

ADCLK = 1; // pull up the CLK terminal

_nop_();

_nop_();

ADCLK = 0; //Pull down the CLK end to form a falling edge 2

_nop_();

_nop_();

ADDI = channel; //Low level is CH0, high level is CH1 

ADCLK = 1; // pull up the CLK terminal

_nop_();

_nop_();

ADCLK = 0; // Pull down the CLK end to form a falling edge 3

ADDI = 1; //Control command ends (necessary after testing)

that = 0;

// Start reading the converted data below and output it in sequence starting from the highest bit (D7~D0)

for(i = 0;i < 8;i++)

{

  dat <<= 1;

  ADCLK=1; //Pull up the clock terminal

  _nop_();

  _nop_();

  ADCLK=0; //Pull the clock end low to form a clock pulse

  _nop_();

  _nop_();

  gives |= ADD;

}

ndat = 0; //Record D0

if(ADDO == 1)

ndat |= 0x80;

// Next, continue reading the reverse data (from D1 to D7) 

for(i = 0;i < 7;i++)

{

  ndat >>= 1;

  ADCLK = 1; // pull up the clock terminal

  _nop_();

  _nop_();

  ADCLK=0; //Pull the clock end low to form a clock pulse

  _nop_();

  _nop_();

  if(ADDO==1)

  ndat |= 0x80;

}   

ADCS=1; //Pull up the CS terminal to end the conversion

ADCLK=0; //Pull down the CLK terminal

ADDI=1; //Pull up the data terminal and return to the initial state

if(that==ndat)

return(that);

else

return 0;   

}

/*****Main function*****/

void main(void)

{

InitTimer(); //Initialize the timer

EA=1; //Global interrupt switch

TR0=1;

ET0=1; //Start timer 0

BEEP=0;

led_h=1;

led_l=1;

JDQ=1;

check_wendu();

check_wendu();

lcd_init(); //Initialize display

delay1ms(100);

lcd_init(); //Initialize display

delay1ms(100);

while(1)

{

if(hujiao==0)

{

   Delay(2000);

   do{}while(hujiao==0);

   flag=~flag;

}

checkkey();

  abc = ADC0832(1,0); //Differential mode, CH0-CH1

  abc = abc*19.607843; //Convert to actual voltage for easy display

  abc=abc/1000%10;

    check_wendu();

disp();

baojing();

if(flag==1){Alarm1();JDQ=0;}

else Alarm(); //Alarm detection

if(set_st==0) wr_com(0x0c);

if(set_st==1)

{

wr_com(0xc6);

wr_com(0x0d);

delay1ms(150);

}

if(set_st==2)

{

wr_com(0xca);

wr_com(0x0d);

delay1ms(150);

}

if(set_st==3)

{

wr_com(0xcd);

wr_com(0x0d);

delay1ms(150);

}

}

}/*****END*****/