Ambient light and micro distance detection system based on stm32f1

Ambient light and distance detection

One 、 Project requirements

1. Development board : STM32F103ZET6 Development board

2. Project requirement :

 (1). When the ambient light intensity reaches a certain value , Buzzer alarm prompt ;

 (2). When the distance sensor detects that there is a block before a certain distance, it will start to alarm constantly ;

 (3). Design Android mobile phone APP, Display ambient light information .

  (4). WIFI Using a punctual atom ESP8266 modular ,WIFI This side is set to AP Pattern , establish TCP The server , Mobile connection ESP8266 Of WIFI, Open mobile phone APP Connect WIFI Created TCP The server , receive WIFI The transmitted light intensity is displayed in real time .

(5). OLED display Real time display of ambient light and distance sensor values , Press the key to switch the display page

Two 、Android mobile phone APP Compilation instructions

Android mobile phone APP use C++ And QT framework design .

Core code ：

#include "widget.h"#include "ui_widget.h"Widget::Widget(QWidget *parent)    : QWidget(parent)    , ui(new Ui::Widget){    ui->setupUi(this);    this->setWindowTitle(" Ambient light display ");    SetStyle(":/CarControl.qss");    /*1.  Instantiation  QNetworkAccessManager*/    manager = new QNetworkAccessManager(this);    // Set up and open the database     if (QSqlDatabase::contains(LOG_IN_DATABASE_CONNECT_NAME))    {        database = QSqlDatabase::database(LOG_IN_DATABASE_CONNECT_NAME);    }    else    {        // Database type         database = QSqlDatabase::addDatabase("QSQLITE",LOG_IN_DATABASE_CONNECT_NAME);        database.setDatabaseName(LOG_IN_DATABASE_NAME); // Database name         database.setUserName("xl");  // user name         database.setPassword("123456"); // password     }    // Open database , Open the database if it exists , Create automatically if it doesn't exist     if(database.open()==false)    {        Log_Text_Display(" Database open failed . Please check the program running path and permissions .\n");    }    else    {        Log_Text_Display(" Successfully connected to database .\n");    }    // database :   Build table , If it exists, it is not created , Create... If it doesn't exist     QSqlQuery sql_query(database);    // The query name of the following statement is CarData  Whether the table exists .    sql_query.exec(QString("select count(*) from sqlite_master where type='table' and name='%1'").arg("CarData"));    if(sql_query.next())    {        if(sql_query.value(0).toInt()==0)        {           Log_Text_Display(" Database tables do not exist . Ready to create .\n");           // Create a table   Create a table statement ：create table <table_name> (f1 type1, f2 type2,…);           /* CREATE TABLE  Is a keyword that tells the database system to create a new table .            * CREATE TABLE  Statement followed by the unique name of the table             *  Or identification */           /* The following statement :  Create a name CarData Table of , The fields are respectively stored   Time 、 temperature 、 humidity 、 longitude 、 latitude */           QString create_sql = "create table CarData(id int primary key, time varchar(100),light varchar(100))";           sql_query.prepare(create_sql);           if(!sql_query.exec())           {               Log_Text_Display(" Database table creation failed .\n");           }           else           {               Log_Text_Display(" Database table created successfully .\n");           }        }        else        {            Log_Text_Display(" Database tables exist . No need to create .\n");        }    }    ui->stackedWidget->setCurrentIndex(0);}Widget::~Widget(){    delete ui;}// Set the specified style void Widget::SetStyle(const QString &qssFile) {    QFile file(qssFile);    if (file.open(QFile::ReadOnly)) {        QString qss = QLatin1String(file.readAll());        qApp->setStyleSheet(qss);        QString PaletteColor = qss.mid(20, 7);        qApp->setPalette(QPalette(QColor(PaletteColor)));        file.close();    }}/* engineering : SmartHome date : 2021-04-26 author : DS Brother Bruce Lee's environment : win10 QT5.12.6 MinGW32 function :  The log shows */void Widget::Log_Text_Display(QString text){    QPlainTextEdit *plainTextEdit_log=ui->plainTextEdit_log;    // Set the cursor to the end of the text     plainTextEdit_log->moveCursor(QTextCursor::End, QTextCursor::MoveAnchor);    // When the number of text exceeds a certain range, it is cleared     if(plainTextEdit_log->toPlainText().size()>1024*4)    {        plainTextEdit_log->clear();    }    plainTextEdit_log->insertPlainText(text);    // Move the scroll bar to the bottom     QScrollBar *scrollbar = plainTextEdit_log->verticalScrollBar();    if(scrollbar)    {        scrollbar->setSliderPosition(scrollbar->maximum());    }}/* engineering : CarControl date : 2021-04-27 author : DS Brother Bruce Lee's environment : win10 QT5.12.6 MinGW32 function :  Connect to server */void Widget::on_pushButton_connect_clicked(){    if(ui->pushButton_connect->text()==" Connect "){        // Start connecting to server         NewClinet();    }    else    {        if(LocalTcpClientSocket)        {            LocalTcpClientSocket->close();        }    }}// Client mode ： Create client void Widget::NewClinet(){    if(LocalTcpClientSocket)    {        LocalTcpClientSocket->close();        delete  LocalTcpClientSocket;        LocalTcpClientSocket=nullptr;    }    /*1.  Create a local client TCP Socket */    LocalTcpClientSocket = new QTcpSocket;    /*2.  Setup server IP Address */    QString Ipaddr=ui->lineEdit_ip->text();    QHostAddress FarServerAddr(Ipaddr);    /*3.  Connect the signal slot of the client */    connect(LocalTcpClientSocket,SIGNAL(connected()),this,SLOT(LocalTcpClientConnectedSlot()));    connect(LocalTcpClientSocket,SIGNAL(disconnected()),this,SLOT(LocalTcpClientDisconnectedSlot()));    connect(LocalTcpClientSocket,SIGNAL(readyRead()),this,SLOT(LocalTcpClientReadDtatSlot()));    /*4.  Try connecting to the server host */    int prot=ui->lineEdit_port->text().toInt();    LocalTcpClientSocket->connectToHost(FarServerAddr,prot);}// Client mode ： Respond to actions after connecting to the server void Widget::LocalTcpClientConnectedSlot(){    ui->pushButton_connect->setText(" To break off ");    Log_Text_Display(" Successfully connected to the server ...\n");}// Client mode ： Disconnect the server void Widget::LocalTcpClientDisconnectedSlot(){   ui->pushButton_connect->setText(" Connect ");   Log_Text_Display(" Disconnect from the server ...\n");}// Client mode ： Read the data sent by the server // Temperature and humidity :  #123.66void Widget::LocalTcpClientReadDtatSlot(){   QString array=LocalTcpClientSocket->readAll();   QDateTime time = QDateTime::currentDateTime();   // Get the current time of the system    QString   time_str = time.toString("yyyy-MM-dd hh:mm:ss"); // Set the display format    QString text;   text +=array;   text +="\n";   Log_Text_Display(text);   // Parsing data    if(array.at(0)=='#')   {       array.remove('#');       QString T_str=array;       ui->label_light->setFont(QFont("Times", 60, QFont::Bold));       ui->label_light->setAlignment(Qt::AlignHCenter); // Horizontal center        ui->label_light->setText(T_str+"%");       // Save data to database        QSqlQuery sql_query(database);       // The most inquired ID       QString select_max_sql = "select max(id) from CarData";       int max_id = 0;       sql_query.prepare(select_max_sql);       if(!sql_query.exec())       {           Log_Text_Display(" Database maximum ID To find the failure .\n");       }       else       {           while(sql_query.next())           {               max_id = sql_query.value(0).toInt();           }           Log_Text_Display(QString("data base max id:%1\n").arg(max_id));           // Add data            // insert data   Insert statement ：insert into <table_name> values (value1, value2,…);           QString insert_sql = tr("insert into CarData values(?,?,?)");           sql_query.prepare(insert_sql);           sql_query.addBindValue(max_id+1); //id           sql_query.addBindValue(time_str); // Time            sql_query.addBindValue(T_str);    // The ambient light            if(!sql_query.exec())           {              Log_Text_Display(" Data insertion failed .\n");           }       }   }}/* engineering : AmbientLightDisplay date : 2021-05-03 author : DS Brother Bruce Lee's environment : win10 QT5.12.6 MinGW32 function :  Historical ambient page */void Widget::on_pushButton_history_clicked(){    ui->stackedWidget->setCurrentIndex(1);}/* engineering : AmbientLightDisplay date : 2021-05-03 author : DS Brother Bruce Lee's environment : win10 QT5.12.6 MinGW32 function :  Current ambient page */void Widget::on_pushButton_current_clicked(){    ui->stackedWidget->setCurrentIndex(0);}/* engineering : AmbientLightDisplay date : 2021-05-03 author : DS Brother Bruce Lee's environment : win10 QT5.12.6 MinGW32 function :  Delete all */void Widget::on_pushButton_del_all_clicked(){    QString cmd;    cmd = QString("delete from CarData");    QSqlQuery sql_query(database);    if(!sql_query.exec(cmd))    {        Log_Text_Display("delete table Error.\n");    }}/* engineering : AmbientLightDisplay date : 2021-05-03 author : DS Brother Bruce Lee's environment : win10 QT5.12.6 MinGW32 function :  Look at historical data */void Widget::on_pushButton_ViewHistory_clicked(){    // Specify the database for the operation     QSqlQuery sql_query(database);    // Query all data     sql_query.prepare("select * from CarData");    if(!sql_query.exec())    {        Log_Text_Display(" Database query error .\n");    }    else    {        while(sql_query.next())        {           // int id = sql_query.value(0).toInt(); //ID            QString time = sql_query.value(1).toString(); // Time             QString T_str = sql_query.value(2).toString(); // light             QString show_text=QString("%1,%2%\n").arg(time).arg(T_str);            QPlainTextEdit *plainTextEdit_log=ui->plainTextEdit_log;            // Set the cursor to the end of the text             plainTextEdit_log->moveCursor(QTextCursor::End, QTextCursor::MoveAnchor);            plainTextEdit_log->insertPlainText(show_text);            // Move the scroll bar to the bottom             QScrollBar *scrollbar = plainTextEdit_log->verticalScrollBar();            if(scrollbar)            {                scrollbar->setSliderPosition(scrollbar->maximum());            }        }    }}

3、 ... and 、Android mobile phone APP effect

Four 、 Introduction to required hardware

4.1 STM32F103ZET6 Development board

STM32 Series is designed for high performance 、 Low cost 、 Low power embedded application design ARM Cortex-M0,M0+,M3, M4 and M7 kernel （ST's product portfolio contains a comprehensive range of microcontrollers, from robust, low-cost 8-bit MCUs up to 32-bit ARM-based Cortex-M0 and M0+, Cortex-M3, Cortex-M4 Flash microcontrollers with a great choice of peripherals. ST has also extended this range to include an ultra-low-power MCU platform) [1] .

It is divided into different products according to the kernel architecture ：

Mainstream products （STM32F0、STM32F1、STM32F3）、 Ultra low power products （STM32L0、STM32L1、STM32L4、STM32L4+）、 High performance products （STM32F2、STM32F4、STM32F7、STM32H7）

4.2 0.96 " OLED display —SPI Interface

OLED The display screen is made of electromechanical self light emitting diodes . Due to the self luminous organic electroluminescent diode at the same time , No backlight 、 High contrast 、 Thin 、 A wide range of perspectives 、 Quick reaction 、 Can be used for flexible panels 、 It has a wide temperature range 、 Excellent properties such as simple structure and process , It is considered to be the next generation of flat panel display emerging application technology .

4.3 Ambient light sensor

This kind of BH1750 The ambient light sensor is built-in 16 Bit analog-to-digital converter , It can directly output a digital signal , No more complicated calculations are needed . This is a more sophisticated and easy to use version of a simple resistor , By calculating the voltage , To get valid data . This ambient light sensor can be directly measured by photometer . The unit of light intensity is lumen "lx". When an object is illuminated in uniform light, it can obtain... Per square meter 1lx Luminous flux of , Their light intensity is 1lx. Sometimes in order to make full use of the light source , You can add a light source reflector . In that way, more luminous flux can be obtained in some directions , To increase the brightness of the illuminated surface .

application

This sensor mainly measures light intensity ：

Car headlights

Flashlight

Photographic lighting

Portable game console

Digital camera

Adjust the phone LCD Backlight in the screen and key area, etc

technical specifications

Supply voltage ：+3-5V

Interface ：I2C

Range and accuracy ：1~65535 lx

You can choose I2C Two forms of address

Small measurement changes (+/-20%)

Size ：0.85x0.63x0.13"(21x16x3.3mm)

Brightness data reference ：

evening ： 0.001-0.02;

moonlit night ： 0.02-0.3;

Cloudy indoor ： 5-50;

Cloudy outdoor ： 50-500;

Sunny day indoor ： 100-1000;

At noon in summer ： about 10*6 energy ;

Illumination when reading books ： 50-60;

Standard illumination of home video ：1400

4.4 ESP8266 A serial port WIFI

ESP8266 Is a serial port WiFi modular , Internal integration MCU It can realize the same communication between the serial ports of single-chip computers ; This module is easy to learn , Small volume , Easy for embedded development .

According to the schematic diagram , Connect the modules to the development board , By configuring the serial port of the development board, you can send ESP8366 Write instructions , Different working modes of configuration module ; It can also be used directly USB turn TTL Module connection , Send the corresponding instructions through the serial assistant , You can also configure ESP8266 Information and working mode of , Of course, you can also read product information .

ESP8266 Module we can understand as a single chip with WiFi function , When we use our own microcontroller for control , Just let the two microcontrollers communicate with each other , The same instruction , Perform the corresponding operation --------- You have to know what the instructions are , After we know the format, we can read out the correct information and send instructions ESP8266 The module can correctly identify , Only in this way can we get the data we want and realize the corresponding functions .

Stable performance :ESP8266EX Wide operating temperature range , And can maintain stable performance , Can adapt to various operating environments .

 

Highly integrated :ESP8266EX Integrated 32 position Tensilica processor 、 Standard digital peripheral interface 、 Antenna switch 、 radio frequency balun、 power amplifier 、 Low noise amplifier 、 Filter and power management module, etc , Only a few peripheral circuits are needed , Can be occupied by PCB Space reduction .

 

low power consumption :ESP8266EX Designed for mobile devices 、 Designed for wearable electronics and Internet of things applications , Through a number of proprietary technologies to achieve ultra-low power consumption .ESP8266EX The power-saving mode is suitable for various low-power application scenarios .

 

32 position Tensilica processor :ESP8266EX Built in ultra low power consumption Tensilica L106 32 position RISC processor ,CPU The clock speed is up to 160 MHz, Support real time operating system (RTOS) and Wi-Fi Protocol stack , Can be as high as 80% The processing power is left to application programming and development .

4.5 Active buzzer

Active buzzer is an electronic buzzer with integrated structure , Using DC voltage supply , It's widely used in computers 、 The printer 、 The photocopier 、 a burglar alarm 、 electronic toy 、 Automotive electronics 、 telephone 、 Timers and other electronic products as voice components . The buzzer is mainly divided into two types: piezoelectric buzzer and electromagnetic buzzer . The buzzer uses letters in the circuit “H” or “HA”（ Old standard “FM”、“LB”、“JD” etc. ） Express .

A simple method to distinguish active buzzer from passive buzzer

The fundamental difference between active buzzer and passive buzzer is that the product requires different input signals ; The ideal signal of active buzzer is DC , Usually marked as VDC、VDD etc. . Because there is a simple oscillation circuit inside the buzzer , It can convert constant direct current into pulse signal of a certain frequency , So as to realize the alternating magnetic field , Drive the aluminum plate to vibrate . However, some active Buzzers can also work under certain AC signals , It only requires high voltage and frequency of AC signal , This kind of working mode generally does not adopt .

The passive buzzer has no internal drive circuit , Some companies and factories are called loudspeakers , It is called a sounder in the national standard . The ideal signal square wave of passive buzzer . If a DC signal is given, the buzzer does not respond , Because the magnetic circuit is constant , The molybdenum sheet cannot vibrate .

4.6 ATK-VL53L0X Laser ranging module

VL53L0X It is based on the Italian French semiconductor patent FlightSense Technology of the second generation laser ranging sensor .

VL53L0X Fully integrated and embedded with a laser sensor for human safety , Advanced filter and ultrafast photon detection array .

It can pass fast 、 accuracy 、 Reliable solutions for longer distance measurements , Open the door for new applications , Further refined ST FlightSense Product line .

The main advantage ：

[1] Less than 30ms Can provide the longest 2 Read the absolute distance of meters （ Unit is mm）

[2] Fast mode ：50 Hz Fast ranging operation

[3] High precision

[4] low power consumption

[5] 4.4×2.4×1 mm Reflow package

[6] Advanced design of ambient light suppression

[7] use 940nm Invisible light

[8] Optical cover support is required

Target application ：

[1] Camera assisted （ Ultra fast auto focus and depth of field ）

[2] Smart phone or laptop energy-saving detection

[3] Gesture control

[4] Unmanned aerial vehicle (uav)

[5] Robotics and industrial control

[6] IoT

[7] Household appliances

technology

VL53L0X The inclusion is based on a SPAD( Single photon avalanche diode ) The sensors are displayed and one that conforms to the first-class safety regulations of the human body VCSEL( Vertical cavity surface emitting lasers ) Integration of 940nm The light source , When used with algorithms running on embedded microcontrollers , The distance of the target object in mm can be directly determined , Even in challenging working conditions , And it has nothing to do with the target reflectivity .VL53L0X Adopt an ultra-low power system architecture , Ideal for wireless and IoT application .VL53L0X Complete documentation package , Such as source code and software API（ Application programming interface ）, It is compatible with the microcontrollers and processors of GF .

Module design

By virtue of it 4.4×2.4×1 mm Small size and reflow soldering compatibility ,VL53L0X Easy to integrate into the main product PCB Or on a soft board , It can be hidden under various cover materials . at present VL53L0X Is the only integrated 940nm wavelength VCSEL Products , Is invisible light , It is not easily affected by the background lighting .

System diagram

5、 ... and 、 Device code

5.1 STM32 Module wiring instructions

The wiring instructions are in main It's already written in the function , Follow .

Be careful ： Because there are many external modules , clear The marked power interface may not be enough , But the development board has a row of connections LCD Of IO mouth And a row Jlink Interface of downloader , Inside all There are power supply pins , Just find the pin wiring of the power supply according to the schematic diagram .

5.2 Equipment operation effect

APP Yes Android Mobile version and Windows System version , I'm going to use Windows Test version ,Android It's the same effect .

1. Connect all module wires , Make sure there are no problems ( Don't connect the power supply incorrectly , Wiring is clearly visible ).

2. compiler , Again Download program to device .

3. Open the serial port to see if the program initialization is normal .

The correct print information is as follows : The server IP The address is 192.168.4.1

At the moment OLED The measured distance and current light intensity can be seen on the small screen .

4. Turn on your computer or mobile phone WIFI Search for ESP8266 The hot Connect

then APP The received ambient light information will be displayed on the .

Pay attention ：IP The address should be changed to 192.168.4.1 Port number : 8080

If you run for a period of time and find that the ambient light is not updated , Just disconnect the server and connect again .

5.3 STM32 Of mian.c Code

#include "stm32f10x.h"#include "led.h"#include "delay.h"#include "key.h"#include "usart.h"#include <string.h>#include "timer.h"#include "esp8266.h"#include "oled.h"#include "fontdata.h"#include "bh1750.h"#include "iic.h"#include "vl53l0x.h"/* Hardware connection mode :ESP8266 A serial port WIFI modular :PB10--RXD  Module receiving pin PB11--TXD  Module sending pin GND---GND  The earth VCC---VCC  Power Supply （3.3V~5.0V）OLED Display wiring ：D0----SCK-----PB14D1----MOSI----PB13RES— Reset ( Low level active )—PB12DC--- Data and command control pins —PB1CS--- Chip selection pin -----PA7GND---GND  The earth VCC---VCC  Power Supply （3.3V） Buzzer : PA6  ( High level response )GND---GND  The earth VCC---VCC  Power Supply （5.0V）IO----PA6BH1750 Ambient light detection module :SDA-----PB7SCL-----PB6GND---GND  The earth VCC---VCC  Power Supply （3.3V~5.0V）ATK-VL53L0X Laser ranging module :XSH----PA15INT---- Break the foot ( Not used )SCL---PC11SDA---PC10GND---GND  The earth VCC---VCC  Power Supply （3.3V~5.0V） Onboard equipment :LED Hardware connection : PB5 PE5KEY Hardware connection :PE3 PE4*/#define ESP8266_WIFI_AP_SSID  "ESP8266_STM32"   // Created hotspot name -- Do not appear in Chinese 、 Special characters such as spaces #define ESP8266_AP_PASSWORD "12345678"     // Create a new hotspot password char esp8266_message[200];// Upload data buffer char OLED_ShowBuff[100];u8 ESP8266_Stat=0;/* The functionality :  Displays the light intensity 、 Measuring distance */void ShowLightDistance(float light,vu16 distance){    sprintf(OLED_ShowBuff,"L: %.2f%%",light);	OLED_ShowString(20,16*1,16,OLED_ShowBuff);    sprintf(OLED_ShowBuff,"D: %dMM",distance);	OLED_ShowString(20,16*2,16,OLED_ShowBuff); }/* The functionality : ESP8266 Display page */void ESP8266_ShowPageTable(void){    if(ESP8266_Stat)OLED_ShowString(0,16*0,16,"WIFI STAT:ERROR");    else OLED_ShowString(0,16*0,16,"WIFI STAT:OK");    // display string     sprintf((char*)OLED_ShowBuff,"%s",ESP8266_WIFI_AP_SSID);    OLED_ShowString(0,16*1,16,OLED_ShowBuff);	        sprintf((char*)OLED_ShowBuff,"%s",ESP8266_AP_PASSWORD);       OLED_ShowString(0,16*2,16,OLED_ShowBuff);    }int main(){   u32 time_cnt=0;   u8 key;   u8 page=0;   float light=0;  // The ambient light    vu16 Distance_data=0;// distance         delay_ms(1000);   delay_ms(1000);       LED_Init();   KEY_Init();   IIC_Init();   BEEP_Init();       // Distance sensor    vl53l0x_init(&vl53l0x_dev);//vl53l0x initialization    vl53l0x_adjust(&vl53l0x_dev); // calibration    vl53l0x_set_mode(&vl53l0x_dev,Default_Mode);// Configure the measurement mode         //OLED initialization    OLED_Init(0xc8,0xa1); //OLED Display initialization -- Normal display ;       // Clear the screen    OLED_Clear(0);       USART1_Init(115200);   TIMER1_Init(72,20000); // Timeout time 20ms   USART3_Init(115200);// A serial port -WIFI   TIMER3_Init(72,20000); // Timeout time 20ms       USART1_Printf(" Initializing WIFI One moment please .\n");      if(ESP8266_Init())   {      ESP8266_Stat=1;      USART1_Printf("ESP8266 Hardware detection error .\n");     }   else   {       ESP8266_Stat=ESP8266_AP_TCP_Server_Mode(ESP8266_WIFI_AP_SSID,ESP8266_AP_PASSWORD,8080);       if(ESP8266_Stat)       {           USART1_Printf("WIFI Configuration error , Status code :%d\r\n",ESP8266_Stat);       }       else       {            USART1_Printf("WIFI Configuration is successful .\r\n");       }  }       while(1)    {            // Key         key=KEY_Scan(0);        if(key==1)        {            // Clear the screen             OLED_Clear(0);                        // Page turning             if(page>=1)            {                page=0;            }            else            {                 page++;            }                             LED1=!LED1;  //LEd Status light         }        else if(key==2)        {            LED1=!LED1;  //LEd Status light             time_cnt=0;            }                  // receive WIFI Returned data         if(USART3_RX_FLAG)        {            USART3_RX_BUFFER[USART3_RX_CNT]='\0';            //USART1_Printf("USART3_RX_BUFFER:%s\n",USART3_RX_BUFFER);                     USART3_RX_CNT=0;            USART3_RX_FLAG=0;        }                      // Regularly transmit to app Upper computer         delay_ms(10);        time_cnt++;        if(time_cnt==30)        {            time_cnt=0;                        // Status light  -- Indicates that the program is still alive             LED2=!LED2;                        // Read the light intensity             light=Read_BH1750_Data();                        // #123.66            sprintf(esp8266_message,"#%0.2f",light);                        // To the cell phone APP Upload data             ESP8266_ServerSendData(0,(u8*)esp8266_message,strlen((char*)esp8266_message));                        Distance_data=vl53l0x_general_start(&vl53l0x_dev);// Perform a measurement             printf("d: %4imm\r\n",Distance_data);// Print measured distance                         // When the distance is less than 100mm  when , Turn on the buzzer    Otherwise closed             if(Distance_data<100)            {                BEEP=1;            }            else            {                BEEP=0;            }                        // When the light intensity is greater than the specified value , Buzzer ring    Otherwise closed             if(light>2000)            {                BEEP=1;            }            else            {                BEEP=0;            }        }                 //OLED display         if(page==0)        {            ShowLightDistance(light,Distance_data);        }        else if(page==1)        {            ESP8266_ShowPageTable();        }    }}