51 MCU CO2 detection display program data

This is a 51 single-chip CO2 detection display program data. The T (TXD) of the carbon dioxide sensor MH-Z19 module is connected to the RXD of the single-chip microcomputer, the R (RXD) is connected to the TXD of the single-chip microcomputer, the V+ is connected to the 5v positive pole of the single-chip microcomputer, and the V- is connected to the ground of the single-chip microcomputer (serial TTL communication requires connecting these four wires); the measurement voltage is 5V; the single-chip microcomputer model is STC89C52, the LCD display model is LCD1602, and the circuit connection is according to the test diagram; the serial communication baud rate is 9600, and the crystal oscillator must be 11.0592M, otherwise it will cause communication failure; the sensor needs to be preheated for 3 minutes when powered on.

#include"reg52.h"

#include"stdio.h"

#include"intrins.h"

#include"lcd1602.H"

#define uchar unsigned char

#define uint unsigned int

#define long unsigned long 

uchar code tab[9]={0xff,0x01,0x86,0x00,0x00,0x00,0x00,0x00,0x79};

uchar  date[]={0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00};

void delayms(uint xms)

{

uint x,y;

for(x=xms;x>0;x--)

for(y=110;y>0;y--);

}

 void send(uchar dat) //Send one byte    

 {

  SBUF=dat;

  while(!IF);

  IF = 0;

 }

void main(void)

{

 uint  tmp;

 flying i;

 TMOD=0x20; // T1 timing mode 2

 SCON=0x40; //Serial working mode 1

 PCON=0x00; //Not doubled

 TH1=TL1=0xfd; //Assign initial value to timer 1 to ensure baud rate is 9600

 TR1=1; //Start timer 1

 REN=1; // Allow serial port to receive

init_1602(); //LCD initialization

delayms(10);

 ES=1; //Open serial port interrupt

 EA=1; //Open the general interrupt

while(1)

{

 for(i=0;i<9;i++) //Send data to the co2 sensor

   {

    send(tab[i]);

   }

  delayms(1000); // Delay one second to refresh the measured data

             tmp=date[2]*256+date[3]; //Calculate the CO2 concentration

if(tmp>9999)

tmp=0;   

        WRITE_LCD1602_COM(0x80+8);

if((tmp/1000)>0)

        WRITE_LCD1602_DAT(LCD1602_Table[tmp/1000]);

        else WRITE_LCD1602_DAT(' '); 

             WRITE_LCD1602_DAT(LCD1602_Table[tmp00/100]);

        WRITE_LCD1602_DAT(LCD1602_Table[tmp0/10]);

        WRITE_LCD1602_DAT(LCD1602_Table[tmp]);

}

   }

 void serial()interrupt 4 //Serial port interrupt service function

  {

   static uchar j;

   ES=0; //Disable interrupts

   if(!RI);

   RI=0; //Clear reception completion mark

   date[j]=SBUF; 

   if(date[0]==0xff) //Judge the first received bit as the data sent by the sensor

      j++;

  else

      j=0;

   if(j==9) //Receive 9 bytes of data sent by the sensor

     j=0; 

   ES=1; //Enable serial port interrupt

  }

//////////////////////////////////////////////////////////////////////////////////////////////

lcd1602.H:

#define uchar unsigned char

#define uint unsigned int           

sbit RS=P2^5;

sbit RW=P2^6;

sbit EN=P2^7;

uchar LCD1602_Table[]="0123456789";

//LCD1602 display scale //0123456789abcdef

uchar code DIS_TIM[16] = {" PPM="}; //Display temperature and humidity

uchar code DIS_STA[16] =   {"  Test is   oK! "}; //

uchar code DIS[16] =       {"alarm       ppm"}; //

extern void delayms(uint xms);

void WRITE_LCD1602_DAT(uchar date)

{

EN=0;

RS=1;

P0=date;

EN=1;

delayms(2);

EN=0;

}

void WRITE_LCD1602_COM(uchar date)

{

EN=0;

RS=0;

P0=date;

EN=1;

delayms(2);

EN=0;

}

void init_1602()

{

  unsigned char i;

RW=0;

WRITE_LCD1602_COM(0x38);

WRITE_LCD1602_COM(0x0c);

WRITE_LCD1602_COM(0x06);

WRITE_LCD1602_COM(0x01);

WRITE_LCD1602_COM(0x80);

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

WRITE_LCD1602_DAT(DIS_TIM[i]);

}