STM32 Project Sharing: Intelligent Water Quality Detection System

Project finished product image:

Bilibili video link:

https://www.bilibili.com/video/BV1sPDVYLEpW/?share_source=copy_web&vd_source=097fdeaf6b6ecfed8a9ff7119c32faf2

(For material sharing, see the end of the article)

01

—

Project Introduction

1. Function Details

STM32 Intelligent Water Quality Detection System

The functions are as follows:

1. The main control chip is the STM32 microcontroller;

2. DS18B20 temperature sensor measures water temperature

3. TDS conductivity sensor measures the conductivity of water

4. PH sensor detects the acidity and alkalinity of water

5. Turbidity sensor measures the turbidity of water

6. OLED display shows the current water temperature, conductivity, turbidity, and pH value in real-time

7. Buttons can set thresholds, triggering a buzzer alarm when exceeded

8. Under abnormal alarm conditions, a relay can be controlled to execute operations

9. Connect to the Gizwits cloud platform, allowing remote viewing of water quality data via the Gizwits mobile app

10. The mobile app displays information and completes control

2. Bill of Materials

• STM32F103C8T6 microcontroller

• OLED screen

• DS18B20 digital temperature sensor

• TDS conductivity sensor

• PH sensor

• Turbidity sensor

• Relay

• Buzzer

02

—

Schematic Design

03

—

PCB Hardware Design

PCB Diagram

04

—

Program Design

#include "main.h"// All header files are included for easy management and calling
#define turbidity_K 2047.19// Function declaration
void Key_Init(void);// Key function declaration
void display(void);
u8 b_1s, eer_f, smart_config;
u8 mod=0;// Display mode
short set_f; // Primary directory number, set data bit marker
u32 begin_code[21] = {0, 30, 500, 4, 10, 500, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 66};// Backup array
set_code[19] verification bit
u32 set_code[21];// Set parameters
char str[32];// Display buffer
short beep_io_flag; // Buzzer flag
u32 set_code[21];// Parameter storage array
u8 run_mod;// Working mode
float PH, PH_temp;// PH variable
u16 temperature;// Temperature storage variable
float TDS_DAT;
float temperature_temp; // Temporary variable for temperature storage
float turbidity, turbidity_temp;// PH value and turbidity value storage variable
float T;
short set_f; // Primary directory number, set data bit marker

int main(void){
    u8 i;
    DelayInit();// System delay function initialization
    DelayMs(500);
    usart2_init(9600);// Serial port 2 initialization
    ADC1_DMA_Config();
    Gizwits_Init();// Gizwits initialization
    Key_Init();// Key pin initialization
    TIM2_Int_Init(10000, 3600);// Output timer, using timer 2 as the 0.5-second interrupt source
    TIM_Cmd(TIM2, ENABLE);// Enable timer 2
    OLED_Init();// OLED screen initialization
    OLED_CLS();// Clear screen
    OLED_ShowCC(0, 0, "====LOADING====");// Display title
    mod = 0;// Boot display boot interface
    DS18B20_Init();// Initialize temperature and humidity sensor
    DelayMs(100);

    Readflash(set_code, 0, 20);  // Read internal saved data
    DelayMs(10);
    if(set_code[19] != 66)// Compare if internal data has been overwritten
    {
        OLED_ShowStr(0, 0, "===NO  FLASH===", 2);
        Writeflash(0, begin_code, 0, 20);// Write initialization data
        DelayMs(500);
        Readflash(set_code, 0, 20);// Read written data
        sprintf(str, "Init System [%2d]", set_code[19]);// Display verification data
        OLED_ShowStr(0, 4, (unsigned char *)str, 2);
        DelayMs(100);
        OLED_CLS();// Clear screen
    }
    gizwitsHandle((dataPoint_t *)&currentDataPoint);// Gizwits protocol processing
    gizwitsSetMode(WIFI_AIRLINK_MODE);// Connect in WIFI_AIRLINK_MODE
    DelayMs(1000);
    userInit();
    OLED_CLS();// Clear screen
    while (1)
    {
        PH = (float)ADCConvertedValue[1]; // PH corresponding AD value
        PH = PH * (3.3/4096) * 2;// PH data processing
        PH = PH * (-5.7541) + 16.654; // PH data processing
        if(PH > 14.0) PH = 14.0;
        if(PH < 0) PH = 0.0;
        PH_temp = PH ;// Assign to temporary variable
        turbidity  = (float)ADCConvertedValue[0]*3.3/4096;// Turbidity corresponding AD value, data processing
        turbidity  = turbidity_K - turbidity*865.68; // Data conversion
        turbidity = turbidity - 200;// Data conversion
        if(turbidity < 35) turbidity = 0; // Turbidity less than 0 equals 0
        turbidity_temp  = turbidity;// Assign to temporary variable
        TDS_DAT = (ADCConvertedValue[2]/4095.0)*3.3;
        TDS_DAT = 66.71*TDS_DAT*TDS_DAT*TDS_DAT-127.93*TDS_DAT*TDS_DAT+428.7*TDS_DAT;
        if(TDS_DAT < 20) TDS_DAT = 0;
        temperature = DS18B20_Get_Temp();// Read temperature and humidity
        temperature_temp = (float)temperature/10;// Assign to temporary variable
        display();// Display program
        key();// Key program
        if(mod==0) run();// Logic control
        userHandle(); // User data collection
        gizwitsHandle((dataPoint_t *)&amp;currentDataPoint);// Gizwits protocol processing
    }
}

05

—

Experimental Results

Material Sharing (Baidu Cloud)

https://pan.baidu.com/s/1_ryza528-IJxOIwjxS8oXA?pwd=vmca Extraction code: vmca

(Or scan the QR code below to obtain)For physical purchase, scan the QR code below