Single chip microcomputer TDS water quality detection source program

1. The system is based on the low-power AT89S51 single-chip microcomputer. The multivibrator composed of the LCD555 timer generates a wave of a certain frequency, and then the I/O interface of the single-chip microcomputer captures the high and low level readout frequencies, and then converts them into resistance values ​​through program algorithm processing. DS18B20 is used as the temperature acquisition module. After data conversion and processing by the host, the temperature value is displayed on the character LCD 1602 display. This design has a simple structure and flexible use, and has great use and research value.

2. Instructions for use: Burn the program to the microcontroller. At this time, disconnect the Bluetooth serial port first. After downloading the program, connect the Bluetooth module, put the probe into the water, open the Bluetooth serial port assistant on the mobile phone, search and pair the Bluetooth, press the button to send data, and the mobile phone will receive the corresponding measurement data.

3. Result: The TDS value of the water quality is measured and the relevant measurement value can be obtained on the mobile phone through Bluetooth transmission

The microcontroller source program is as follows:

/*******************************************************************************

--------------------------------------------------------------------------------

* Experiment name: TDS display test

* Experimental description: LCD1602 displays TDS.

* Connection method: See connection diagram

* Note :

*******************************************************************************/

#include

#include"lcd.h"

#include"temp.h"

unsigned char code buf3[]={"evaluation:Suggested filteringnn"};

unsigned char code buf2[]={"evaluation:Slight solute in waternn"};

unsigned char code buf1[]={"evaluation: less solute in waternn"};

unsigned char code buf4[]={"Warningnn"};  

long caculate_TDS(int temp);

void LcdDisplay(int temp);

void TDSDisplay(int temp);

void send();

void PutString(unsigned char *TXStr);

unsigned int count;

sbit key=P1^4;

sbit key1=P1^3;

unsigned int   FreResultFlag;   

unsigned int FreNum;

/*******************************************************************************

* Function name: Timer0

* Description: Interrupt program, re-assign the value to start timing after the timing time is up, and invert the state of the LED.

********************************************************************************/

void time0(void) interrupt 1  

{        

        unsigned char i;

        TH0=(65536-46083)/ 256;

        TL0=(65536-46083)% 256;                  

        i++;       

        if(i==20)

        {

                 i=0;       

                count=TH1*256+TL1;

                TH1=0x00;

                TL1=0x00;

        }

}

/*******************************************************************************

* Function name: main

* Function: Main function

* Input : None

* Output: None

*******************************************************************************/

        void main()

{       

                                unsigned char flag=1;

                                TMOD=0x51;

                                TH0=(65536-46083)/ 256;

                                TL0=(65536-46083)% 256;                  

                                TH1 = TL1 = 0;

                                EA=1;

                                ET0=1;

                                TR0 = 1;

                                TR1 = 1;

     LcdInit(); //Initialize LCD1602

           LcdWriteCom(0x88); //Write address 80 indicates the initial address

           LcdWriteData('C');

        while(1)

        {

                //LcdDisplay();

// Delay1ms(1000); // refresh once every 1s

                        if( FreResultFlag )                                 

        {

            FreNum = (TH1 * 256 + TL1);  

            TH1    = 0;                                   

            TL1    = 0;

            FreResultFlag = 0;                             

            TR1    = 1;

            TR0    = 1;                                    

                       LcdDisplay(Ds18b20ReadTemp());                     

                                         TDSDisplay(caculate_TDS(Ds18b20ReadTemp()));

                                         send();

                                   UsartConfiguration();                     

                                }

        }

        }

/*******************************************************************************

* Function name: LcdDisplay()

* Function: LCD displays the temperature read

* Input: v

* Output: None

*******************************************************************************/

void LcdDisplay(int temp) //lcd display

{

  unsigned char datas[] = {0, 0, 0, 0, 0}; //define array

        float tp;  

        if(temp< 0) //When the temperature value is negative

          {

                  LcdWriteCom(0x80); //Write address 80 indicates the initial address

            LcdWriteData('-'); //Display negative

                //Because the temperature read is the complement of the actual temperature, subtract 1 and then invert it to get the original code

                temp=temp-1;

                temp=~temp;

                tp=temp;

                temp=tp*0.0625*100+0.5;       

                //Leave two decimal points and *100, +0.5 is rounded, because the decimal point is rounded when the C language floating point number is converted to an integer

                //The number behind is automatically removed, regardless of whether it is greater than 0.5, and after +0.5, the number greater than 0.5 is increased by 1, and the number less than 0.5 is increased by 1.

                //Calculated by ?.5, still after the decimal point.

          }

        else

          {                       

                  LcdWriteCom(0x80); //Write address 80 indicates the initial address

            LcdWriteData('+'); //Display positive

                tp=temp; //Because the data processing has a decimal point, the temperature is assigned to a floating point variable

                //If the temperature is positive, then the original code of the positive number is the complement code itself

                temp=tp*0.0625*100+0.5;       

                //Leave two decimal points and *100, +0.5 is rounded, because the decimal point is rounded when the C language floating point number is converted to an integer

                //The number behind is automatically removed, regardless of whether it is greater than 0.5, and after +0.5, the number greater than 0.5 is increased by 1, and the number less than 0.5 is increased by 1.

                // Add 0.5, or after the decimal point.

        }

        datas[0] = temp / 10000;

        datas[1] = temp % 10000 / 1000;

        datas[2] = temp % 1000 / 100;

        datas[3] = temp % 100 / 10;

        datas[4] = temp % 10;

        LcdWriteCom(0x82); //Write address 80 indicates the initial address

        LcdWriteData('0'+datas[0]); //Hundreds digit

        LcdWriteCom(0x83); //Write address 80 indicates the initial address

        LcdWriteData('0'+datas[1]); //ten digits

        LcdWriteCom(0x84); //Write address 80 indicates the initial address

        LcdWriteData('0'+datas[2]); //unit

        LcdWriteCom(0x85); //Write address 80 indicates the initial address

        LcdWriteData('.'); //Display '.'

        LcdWriteCom(0x86); //Write address 80 indicates the initial address

        LcdWriteData('0'+datas[3]); //Display decimal point  

        LcdWriteCom(0x87); //Write address 80 indicates the initial address

        LcdWriteData('0'+datas[4]); //Display decimal point  

}

/*******************************************************************************

* Function name: TDSDisplay()

* Function: LCD displays the read

* Input: v

* Output: None

*******************************************************************************/

void TDSDisplay(int TDS) //lcd display

{

  unsigned char datas[] = {0, 0, 0, 0, 0, 0}; //define array

//        float tp;  

// if(temp< 0) // when the temperature value is negative

//          {

// LcdWriteCom(0x80+0x40); //Write address 80 indicates the initial address

// LcdWriteData('-'); //Display negative

// //Because the temperature read is the complement of the actual temperature, subtract 1 and then invert it to get the original code

//                temp=temp-1;

//                temp=~temp;

//                tp=temp;

//                temp=tp*0.0625*100+0.5;       

// //Leave two decimal points and *100, +0.5 is rounded, because the decimal point is rounded when the C language floating point number is converted to an integer

// //The number behind is automatically removed, regardless of whether it is greater than 0.5, and after +0.5, the number greater than 0.5 is increased by 1, and the number less than 0.5 is increased by 1.

// //Calculated by ?.5, still after the decimal point.

//

//          }

//         else

//          {                       

// LcdWriteCom(0x80+0x40); //Write address 80 indicates the initial address

// LcdWriteData('+'); //Display positive

// tp=temp; //Because the data processing has a decimal point, the temperature is assigned to a floating point variable

// //If the temperature is positive, then the original code of the positive number is the complement code itself

//                temp=tp*0.0625*100+0.5;       

// //Leave two decimal points and *100, +0.5 is rounded, because the decimal point is rounded when the C language floating point number is converted to an integer

// //The number behind is automatically removed, regardless of whether it is greater than 0.5, and after +0.5, the number greater than 0.5 is increased by 1, and the number less than 0.5 is increased by 1.

// //Add 0.5, or after the decimal point.

//        }

        datas[0] = TDS / 100000;

        datas[1] = TDS % 100000 / 10000;

        datas[2] = TDS % 10000 / 1000;

        datas[3] = TDS % 1000 / 100;

        datas[4] = TDS % 100 / 10;

        datas[5] = TDS % 10 ;

        LcdWriteCom(0x81+0x40); //Write address 80 indicates the initial address