STC15 single chip microcomputer DHT11 temperature and humidity detection (detailed comments) oled display program

I added oled here to display temperature and humidity, using STC15, dht11 modules

#include

#include "intrins.h" // used to provide _nop_(); function

#include "OLED_Contrul_Hygrothermograph.c" //OLED control function

sbit YLED=P3^1;

sbit RLED=P3^0;

sbit DHT=P3^5; //DHT11 module

unsigned int Temperature[3]={1,1,1}; //The first two digits are the integer part, and the last digit is the decimal part

unsigned int Humidity[2]={1,1}; //The returned humidity data only has the integer part

unsigned char Data_Receive[5];

/*##############################################################################################

Design name: Hygrothermograph based on DHT11

Designer: Qinghe

Platform: STC15F104W

Hardware parts

Display: OLED12864 is used to display temperature and humidity

The measurement uses the DHT11 module, and the module information is as follows:

ASATR

-----

NA:DHT11

OC:3.3-5.5V

U1:5-95%RH

U2:-20-60℃

U3:±5%RH±2℃

SN:A1712882A

To ensure accurate delay, the crystal oscillator is set to 12MHz

I borrowed some programs from http://www.51hei.com/bbs/dpj-38067-1.html, and I would like to express my gratitude

##############################################################################################*/

void Delay30us()//@12.000MHz

{

        unsigned char i;

        i=87;

        while(--i);

}

void Delay20ms()//@12.000MHz

{

        unsigned char i,j,k;

        i=1;

        j=234;

        k=113;

        do

        {

                do

                {

                        while(--k);

                }while(--j);

        }while(--i);

}

void Delay1s()//@12.000MHz

{

        unsigned char i,j,k;

        i=46;

        j=153;

        k=245;

        do

        {

                do

                {

                        while(--k);

                }while(--j);

        }while(--i);

}

void OLED_Display() //OLED display driver function

{

        OLED_DataDisplay_T(56,4,Temperature); //Display temperature at the specified position

        OLED_DataDisplay_H(56,6,Humidity); //Display humidity at the specified location

}

void DHT_Collect()//Temperature collection function

{

        unsigned char i,j;//for loop variable

        unsigned char t; //Timeout judgment

        unsigned char dat8=0; //8 bits of data read at a time, need to be read 5 times

        unsigned int CheckValue=0; //Checksum

        DHT=0; //Host sends start signal

        Delay20ms(); //Host pulls the bus down for at least 18ms

        DHT=1; //Host pulls up the bus for 20~40us

        Delay30us();

        t=80; //Set the timeout waiting time

        while(DHT&&t--); //Wait for DHT11 to pull down the bus

        if(t==0)//timeout

        {

                DHT=1;

        }

        t=250; //Set the timeout waiting time

        while(!DHT&&t--); //Wait for DHT11 to pull up the bus

        if(t==0)//timeout

        {

                DHT=1;

        }

        t=250; //Set the timeout waiting time

        while(DHT&&t--); //Wait for DHT11 to pull down the bus

        if(t==0)//timeout

        {

                DHT=1;

        }

        for(j=0;j<5;j++) //5 times reading

        {

                for(i=0;i<8;i++) // 1 time 8 bits

                {

        //Wait for 50us to start the time slot

                        t=150; //Set the timeout waiting time

                        while(!DHT&&t--); //Wait for DHT11 to pull up the bus

                        if(t==0)//timeout

                        {

                                DHT=1;

                        }

                        t=0; //Record time clear

                        while(DHT&&++t); //Wait and record the duration of high level

                        dat8<<=1;

                        if(t>30) //High level lasts longer (70us)

                        dat8+=1; //transmission value is 1

                }

                Data_Receive[j]=dat8;

        }

        Delay30us(); //Wait for DHT11 to pull down for 50us

        Delay30us();

        DHT=1;

        for(i=0;i<4;i++)

        {

                CheckValue+=Data_Receive[i]; //Calculate the check value

        }

        if((unsigned char)CheckValue==Data_Receive[4])//比对

        {

                Temperature[0]=Data_Receive[2]/10;

                Temperature[1]=Data_Receive[2]%10;

                Temperature[2]=Data_Receive[3]%10;

                Humidity[0]=Data_Receive[0]/10;

                Humidity[1]=Data_Receive[0]%10;

        }

}

void sys_init()//system initialization function

{

        YLED=1;

        RLED=1;

        OLED_Init(); //OLED initialization

        OLED_CLS(); //Clear screen

        OLED_FormTitle(0,0); //Display title text Linyar Lab.

        OLED_FormName(0,2); //Display Hygrothermograph name

        OLED_FormLine(0,3); //Display a horizontal line

        OLED_FormTemp(8,4); //Display temperature text

        OLED_FormHumi(16,6); //Display humidity text

        OLED_AnyChar_16X16(96,4,TempChar); //Display the Celsius degree ℃ character at row 4 (each row is 16 pixels high) and column 96 pixel position

        OLED_AnyChar_8X16(88,6,HumiChar); //Display the percent sign % at row 6 (each row is 16 pixels high) and column 88 pixels

        OLED_AnyChar_8X16(72,4,PointChar); //Display the colon character at row 4 (each row is 16 pixels high) and column 72 pixels

}

void main()

{

        P3M0=0X00;

        P3M1=0X00;

        sys_init();

        while(1)

        {

                DHT_Collect(); //DHT11 data collection

                YLED=1;RLED=0;//Light state conversion

                OLED_Display(); //OLED display function

                RLED=1;YLED=0;//Light state conversion

                Delay1s();

                Delay1s(); //Note: A long delay is required, otherwise it will read 0

        }

}