Environment regulation system based on Internet of things (esp32-c3+onenet+ wechat applet)

This is a course design I recently did , Real time monitoring of indoor temperature, humidity and light intensity , Display the monitoring data in real time on the wechat applet and issue commands to control the fan switch and the forward and reverse rotation of the steering gear ( So as to realize the switch of simulation curtain ). There are two modes of control , One is manual control , Remotely control the device switch through wechat applet , One is equipment automatic control , Set the threshold of temperature and humidity to control the switch of the fan , By setting the threshold of light intensity, we can control the forward and reverse rotation of the steering gear ( switch ).

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1、 Overall block diagram of hardware system

​ System to MCU Design sensing control nodes for core devices . Air temperature and humidity sensor 、 Light sensor 、 The gas sensor will collect the analog data through AD Convert to digital signal transmission and input directly MCU Of I/O mouth ; All perceptual data passes WiFi The module is sent to the cloud . At the same time, the control equipment is driven by setting parameters .

2、 Hardware design flow chart

3、 Software design flow chart of lower computer

4、 Device selection

1、 Air temperature and humidity sensor

choose DHT11 Compound digital air temperature and humidity sensor , The temperature and humidity sensing module is integrated inside , When the sensor module works, it will call the calibrated coefficient in the production process for calibration . It uses the one on the right DHT11

2、 Light sensor ：

Photodiodes LM393 Optical signals can be （ Light intensity ） Convert to electrical signal ; Then the comparison circuit compares the voltage passing through the photosensitive resistor with the voltage passing through the potentiometer , And to DO The port outputs high voltage or low voltage for users ; and AO The port is a circuit that directly passes through the photosensitive resistance to reduce the voltage , So the output is in GND and VCC Any voltage value between ; Of course VCC and GND It is the basic condition for the normal operation of module components and chips , Indispensable ！ The light sensor is shown in the figure 10 Shown .

3、 Steering gear selection

choose SG90 The steering gear receives PWM The signal , Make it enter the internal circuit to generate a bias voltage , Trigger the motor to drive the potentiometer to move through the reduction gear , When the voltage difference is zero , The motor stops , So as to achieve the effect of servo . That is to give the steering gear a specific PWM The signal , The steering gear rotates to a specific angle . I bought it 360 Rotatable steering gear

4、 Fan

​ I bought this kind of two thread

5、Onenet Cloud platform

1、 Create products

Console —> Multiple access –> Add product

About product name 、 industry 、 Those categories can be selected by yourself , Here is chosen mqtt Old agreement

Click on the one we just created dht11, Then click Product Overview , Remember our products id, You can use it in the back

2、 Create device

Click on the device list -> Click Add Device on the right , Equipment name and authentication information need to be filled in , Authentication information device connection onenet It works , And equipment id Number

3、 Create data flow

First click on data flow , Then click data flow template management , Finally, add a data flow template

The data stream name set here will be followed by , Here I created the temperature 、 humidity 、 The lamp 、 Data flow of illumination and so on .

6、 Lower computer code writing

1、 How to connect the device to the Internet

Here you can call wifi library

#include <WiFi.h>

const char* ssid     = "3671"; //wifi name 
const char* password = "05210835";//wifi password 

2、 Temperature and humidity

My sensor is DHT11, You can also call the library here ( You can go to the management library to download DHT sersor library This library )

#include "DHT.h"

Definition DHT11, I connect the data pin to IO7 mouth

#define DHTPIN 7 // io7
#define DHTTYPE DHT11 // DHT 11
DHT dht(DHTPIN, DHTTYPE);

3、 photosensitive

Here I choose Io0 The port is equipped with an analog-to-digital converter io mouth , Convenient data conversion

#define LDR_PIN 0 // Photosensitive interface 0
const float GAMMA = 0.7;
const float RL10 = 50;
float guang(){
    
  int analogValue = analogRead(LDR_PIN);
  float voltage = analogValue / 1024. * 5;
  float resistance = 2000 * voltage / (1 - voltage / 5);
  float lux = pow(RL10 * 1e3 * pow(10, GAMMA) / resistance, (1 / GAMMA));
   Serial.print(lux); 
  return lux;

}

4、 The steering gear

// setting PWM properties
#define do 10 // Steering gear interface 
const int freq = 5000;// Set the frequency 
const int ledChannel = 0;// Channel number , Value 0 ~ 15
const int resolution = 8;// Count digits , Value 0 ~ 20
unsigned long time1=544;
bool direction1=true;

setup function

 // Steering gear module 
  pinMode(do, OUTPUT);
  digitalWrite(do,HIGH);
  delayMicroseconds(544);
  digitalWrite(do,LOW);

loop function

driection1 It is used to judge whether the current state of the steering gear is on or off

 // The steering gear 
 if(direction1 && vm <400)
  {
    
    time1+=10;
    digitalWrite(do,HIGH);
    delayMicroseconds(time1);
    digitalWrite(do,LOW);
    delay(5);
    if (time1>=2600)
    direction1=false;
    dji=1;
  }
  if(direction1==false && vm >400)
  {
    
    time1-=10;
    digitalWrite(do,HIGH);
    delayMicroseconds(time1);
    digitalWrite(do,LOW);
    delay(5);
   
    if (time1<=544)
    direction1=true;
    dji=0;
  }

5、 Fan

Here, the fan switch is controlled by the high and low level of the relay

const int fengshan=8; // Relay in Interface 

setup function

  pinMode(fengshan,OUTPUT);

loop function

If the temperature exceeds 30 Just start the fan

if(t>30){
    
     digitalWrite(fengshan, HIGH);  //
     shan =1;
  }

6、OLED

​ My previous blog has a detailed introduction , If you don't have environment configuration or don't understand, you can click the link below to jump to the past to learn

https://blog.csdn.net/weixin_44107116/article/details/122491820

7 、 Access address

mqtt The interface pin number of the protocol is 6002

const char *mqtt_server = "183.230.40.96"; //onenet  Of  IP Address 
const int port = 6002;                     // Port number 

8、 How to send data to onenet

Here we need to check onenet Related documents of

https://open.iot.10086.cn/doc/v5/develop/detail/463

#define mqtt_devid "884337606" // equipment ID
#define mqtt_pubid "487632" // product ID
// Authentication information 
#define mqtt_password "20222222" // Authentication information 
char msg_buf[200];               // Send message buffer 
char msgJson[80]; // To send json Formatted data 
unsigned short json_len = 0;                      //json length 
// Information templates 
char dataTemplate[] = "{\"temp\":%.2f,\"humi\":%.2f,\"led\":%d,\"feng\":%d,\"guang\":%.2f,\"doji\":%d,\"Air\":%d}";  // temp humi Wait, we need to onenet Corresponding 

void sendTempAndHumi()
{
    
  if (client.connected())
  {
    
    //dht.readHumidity()
       snprintf(msgJson,80,dataTemplate,dht.readTemperature(),dht.readHumidity(),god,shan,guang(),dji,Air()); 
    json_len = strlen(msgJson);                   //msgJson The length of 
    msg_buf[0] = char(0x03);                       // The data to be sent must be in accordance with ONENET Send your request ,  According to the requirements , The number one data is 3
    msg_buf[1] = char(json_len >> 8);              // The second bit of data is the upper eight bits of the data length to be sent 
    msg_buf[2] = char(json_len & 0xff);            // The third bit of data is the lower eight bits of the length of the data to be sent 
    memcpy(msg_buf + 3, msgJson, strlen(msgJson)); // from msg_buf Starting from the fourth place , Put in the data to be transmitted msgJson
    msg_buf[3 + strlen(msgJson)] = 0;              // Add one 0 As the last ,  So what to send msg_buf Be on it 

    Serial.print("public the data:");
    Serial.print(msgJson);
    client.publish("$dp", (uint8_t *)msg_buf, 3+strlen(msgJson));
    // Send data to the subject 
    delay(500);
    
  }
}

stay setup() The function defines each 5 Send data to... Once per second onenet

 tim1.attach(5, sendTempAndHumi);                            // Every time 5 Call the send data function once every second sendTempAndHumi

9、 Issue order

stay setup() Function subscription command issue topic

  client.setCallback(callback); // Subscribe to the command and issue the topic 

// Received callback from subject ,  Note that this callback implements three formal parameters  1:topic  The theme , 2: payload:  The message  3: length:  length 
void callback(char *topic, byte *payload, unsigned int length)
{
    
  Serial.print("Message arrived [");
  Serial.print(topic);
  Serial.print("] ");
  for (int i = 0; i < length; i++) {
    
    Serial.print((char)payload[i]);
  }
  Serial.println();
 
  if ((char)payload[0] == '0') {
    
    digitalWrite(led, LOW);   // 
    god=0;
  }
  else if ((char)payload[0] == '1') {
    
    digitalWrite(led, HIGH);  // 
    god=1;
  }
  else if ((char)payload[0] == '2') {
    
    digitalWrite(fengshan, HIGH);  // 
    shan=1;
  }
  else if ((char)payload[0] == '3') {
    
    digitalWrite(fengshan, LOW);  // 
    shan=0;
  }
  // Turn off 
   else if ((char)payload[0] == '5') {
    
    for(time1;time1>=544;time1-=10){
    
       digitalWrite(do,HIGH);
      delayMicroseconds(time1);
      digitalWrite(do,LOW);
      delay(5);
     if(time1<=544){
    
       direction1=true;
       dji=0;
       delay(5000);
      }
    }
     
    
  }
  // open 
   else if ((char)payload[0] == '4') {
    
    for(time1;time1<=2600;time1+=10){
    
    digitalWrite(do,HIGH);
    delayMicroseconds(time1);
    digitalWrite(do,LOW);
    delay(5);
    if (time1>=2600){
    
      direction1=false;
      dji=1;
      delay(5000);
    }
    }
  }
  else{
    
    
  }

}

10、led The lamp

About lights , It was meant to be connected externally , But I want to be lazy after checking the schematic diagram , After all, the development board comes with two lights and RGB The lamp . So here's what I chose 18 The light of the interface , because 19 The light is always on , So don't choose it .

const int led =18; // Lamp interface 

stay setup() Define that the lamp is output

pinMode(led,OUTPUT);// Output 

I set up one here god Variable , Initialization is 0, That is, the light is not on , Wait until the command is received before changing ,1 Turn on the lights .

11、PCB plate

Because there are too many devices , I can't connect it with DuPont cable , It's not beautiful to use bread board , Later, I spent a little time learning EDA, With jialichuang's Lichuang EDA Draw a board to use , Here Amway jialichuang , It's really easy to use , And no more than ten centimeters of punching board is completely free , This domestic super nice!!!（ Dexter type-A The interface doesn't work , For reference only ）

7、 WeChat developer tools

​ This is a development tool provided by wechat , There's a framework , It is also convenient for us to deploy the project online . Here I focus on how to get onene Data and send instructions

1、 Wechat interface

2、 obtain Onenet Of API Interface

go back to onenet Device list for , Then click the details on the right to see the details of the device , Copy API Address and API-key, One device can have more than one apikey, Add by yourself .

3、 Inquire about OneNet Platform multi protocol access document , Here's a direct look at MQTT Of API Use

4、 I use ApiPost To test whether data can be obtained

5、 Wechat applet access OneNet data

1、 stay wxml I added a click event to the button , Name it points, The corresponding is in index.js You also need to add corresponding functions

 points:function(e) {
    
 
 
 },

​ 2、 Refer to the applet documentation , I use wx.request get data

points:function(e) {
    
    var that = this
    wx.request({
    
      url: 'http://api.heclouds.com/devices/xxxxxxxxxx/datapoints?', //xxz Fill in your equipment here id
      // equipment ID
      //api-key
      header:{
    
        "api-key":"xxxxxxx"  // Here's your api-key
      },
      data:{
    
        limit:1
      },
      method :"GET",
       // To be successful 
      success:function(res){
    
       that.setData({
    
          wendu:res.data.data.datastreams[0].datapoints[0].value,
         time:res.data.data.datastreams[0].datapoints[0].at,
         shidu:res.data.data.datastreams[1].datapoints[0].value,
         led:res.data.data.datastreams[2].datapoints[0].value, // there shidu Want to follow wxml{
    {shidu}}  The same name 
        
       })    
      }
    })
  },

​ 3、 About how to display to specific numbers , Differ from man to man , The following two lines of code are based on json Data to locate

shidu:res.data.data.datastreams[0].datapoints[0].value, 
wendu:res.data.data.datastreams[1].datapoints[0].value,

6、 Wechat applet sends commands

Here I also encapsulate two functions , One is hair 1 value , One hair 0 value , Because our embedded code is written 1 Means turn on the light ,0 For turning off the lights . Here, the function of turning on the light is used to introduce

 openled:function(e){
    
    wx.request({
    
      url: 'http://api.heclouds.com/cmds?device_id=*****',//* Write your device number here id
      // equipment ID
      //api-key
      header:{
    
        'content-type':'application/json',
        "api-key":"xxxxxxx"  // Here's your api-key
      },

      method :"POST",
      data:1,// data 1 It's for the light 
      success(res){
    
        console.log(" Control success , Lights on ")
        console.log(res)
        console.log(res.data);

      }

    })
  },

7、 Data Refresh

In fact, these online function examples , I tried page refresh 、 Refresh regularly , If there is no click event on the page, you can use the following two methods . But if there is a click event, it is still refreshed regularly

Refresh regularly

  /** *  Life cycle function -- Monitor page loading  */
  onLoad: function (options) {
    
    this.points()  // This is what I got onenet Functions of data 
    var that=this
    setInterval(function(){
    
      that.points();
    },3000   // Here I set 3 Refresh every second 
    )

  },

8、 Select the corresponding instruction in the drop-down list to send data

Here I have written a separate blog, which can be learned in detail by clicking the link below

https://blog.csdn.net/weixin_44107116/article/details/125520404

9、 Data visualization

Here I refer to another blogger's blog , Simple and easy to understand , I made a little improvement here , Show dates only , The year is not displayed . Click the picture to switch to the visual interface , I wrote the temperature 】 I 、 humidity 、 Light these three .

https://blog.csdn.net/qq_52827563/article/details/121726546?

10、 Check whether the equipment is online

Then I set a precondition based on the drop-down list , Instructions can only be sent when the device is online , Otherwise, only the information prompt box will pop up .

 postdata:function(shuj){
    
    wx.request({
    
      url: 'https://api.heclouds.com/cmds?device_id= equipment id',
      // equipment ID
      //api-key
      header:{
    
        'content-type':'application/json',
        "api-key":" Yours api-key"
      },

      method :"POST",
      data:shuj, // Data command 
      success(res){
    
        wx.showToast({
    
          title: ' Control command sent ',
          image:"/images/gong.png",
          duration:2000,
          mask:true
        })
        console.log(" Control success , Control command completed ")
        console.log(res)
        console.log(res.data);
      },
      fail(res){
    
        wx.showToast({
    
          title: ' request was aborted ',
          image:"/images/errer.png",
          duration:2000,
          mask:true
        })
        console.log(" request was aborted ")
        console.log(res)
        console.log(res.data);
      }
    })
  },
  devicedata:function(){
    
     var that =this;
    wx.request({
    
      url: 'https://api.heclouds.com/devices/884337606',
      // equipment ID
      //api-key
      header:{
    
        'content-type':'application/json',
        "api-key":"9zHJfKbQN=dyGflCM0yaICWHmi8="
      },

      method :"GET",
      success(res){
    
        if (res.data.data.online){
    
          console.log(" The device is connected ");
          that.setData({
    deviceSwitch:1})
        }
        else{
    
         console.log(" Device not connected ");
         that.setData({
    deviceSwitch:0})
        }   
       },
       fail(res){
    
         console.log(" request was aborted ");
       } 
    })
  },

11、 Effect display

Environment regulation system based on Internet of things

Conclusion

Probably the whole IOT process has been completed , By the way, the hardware is wirelessly integrated , The interface and functions of wechat applet have been upgraded and added new things than before , If you want the source code or related information, you can confide in me , But it's not free , This is my personal effort to find out , Also please understand .