TDS Sensor水質硬度傳感器-MQTT

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#include <WiFi.h>
#include <PubSubClient.h> //請先安裝PubSubClient程式庫

#define TdsSensorPin 33       //TDS感測器接入腳位GPIO 33
#define VREF 3.3              // analog reference voltage(Volt) of the ADC
#define SCOUNT  30            // sum of sample point
// ------ 以下修改成你自己的WiFi帳號密碼 ------
char* ssid = "SSID";
char* password = "PASSWORD";

int analogBuffer[SCOUNT];     // store the analog value in the array, read from ADC
int analogBufferTemp[SCOUNT];
int analogBufferIndex = 0;
int copyIndex = 0;

float averageVoltage = 0;
float tdsValue = 0;
float temperature = 25;       // 設定當前環境溫度 (計算PPM需使用溫度資訊)

// median filtering algorithm
int getMedianNum(int bArray[], int iFilterLen){
  int bTab[iFilterLen];
  for (byte i = 0; i<iFilterLen; i++)
  bTab[i] = bArray[i];
  int i, j, bTemp;
  for (j = 0; j < iFilterLen - 1; j++) {
    for (i = 0; i < iFilterLen - j - 1; i++) {
      if (bTab[i] > bTab[i + 1]) {
        bTemp = bTab[i];
        bTab[i] = bTab[i + 1];
        bTab[i + 1] = bTemp;
      }
    }
  }
  if ((iFilterLen & 1) > 0){
    bTemp = bTab[(iFilterLen - 1) / 2];
  }
  else {
    bTemp = (bTab[iFilterLen / 2] + bTab[iFilterLen / 2 - 1]) / 2;
  }
  return bTemp;
}
// ------ 以下修改成你MQTT設定 ------
char* MQTTServer = "broker.mqttgo.io";//免註冊MQTT伺服器
int MQTTPort = 1883;//MQTT Port
char* MQTTUser = "";//不須帳密
char* MQTTPassword = "";//不須帳密
//推播主題1:推播PPM(記得改Topic)
char* MQTTPubTopic1 = "YourTopic/class/TDSPPM";
long MQTTLastPublishTime;//此變數用來記錄推播時間
long MQTTPublishInterval = 1000;//每10秒推撥一次
WiFiClient WifiClient;
PubSubClient MQTTClient(WifiClient);

void setup() {
  Serial.begin(115200);
  pinMode(TdsSensorPin,INPUT);

  //開始WiFi連線
  WifiConnecte();

  //開始MQTT連線
  MQTTConnecte();
}

void loop() {
   static unsigned long analogSampleTimepoint = millis();
  if(millis()-analogSampleTimepoint > 40U){     //every 40 milliseconds,read the analog value from the ADC
    analogSampleTimepoint = millis();
    analogBuffer[analogBufferIndex] = analogRead(TdsSensorPin);    //read the analog value and store into the buffer
    analogBufferIndex++;
    if(analogBufferIndex == SCOUNT){ 
      analogBufferIndex = 0;
    }
  }   
  
  static unsigned long printTimepoint = millis();
  if(millis()-printTimepoint > 800U){
    printTimepoint = millis();
    for(copyIndex=0; copyIndex<SCOUNT; copyIndex++){
      analogBufferTemp[copyIndex] = analogBuffer[copyIndex];
      
      // read the analog value more stable by the median filtering algorithm, and convert to voltage value
      averageVoltage = getMedianNum(analogBufferTemp,SCOUNT) * (float)VREF / 4096.0;
      
      //temperature compensation formula: fFinalResult(25^C) = fFinalResult(current)/(1.0+0.02*(fTP-25.0)); 
      float compensationCoefficient = 1.0+0.02*(temperature-25.0);
      //temperature compensation
      float compensationVoltage=averageVoltage/compensationCoefficient;
      
      //convert voltage value to tds value
      tdsValue=(133.42*compensationVoltage*compensationVoltage*compensationVoltage - 255.86*compensationVoltage*compensationVoltage + 857.39*compensationVoltage)*0.5;
      
      //Serial.print("voltage:");
      //Serial.print(averageVoltage,2);
      //Serial.print("V   ");
      Serial.print("TDS Value:");
      Serial.print(tdsValue,0);
      Serial.println("ppm");

    }
  }

  //如果WiFi連線中斷，則重啟WiFi連線
  if (WiFi.status() != WL_CONNECTED) { WifiConnecte(); }

  //如果MQTT連線中斷，則重啟MQTT連線
  if (!MQTTClient.connected()) {  MQTTConnecte(); }

  //如果距離上次傳輸已經超過10秒，則Publish
  if ((millis() - MQTTLastPublishTime) >= MQTTPublishInterval ) {
    byte tds1 = 0;
    tds1 = tdsValue,0;
    // ------ 將TDS送到MQTT主題 ------
    MQTTClient.publish(MQTTPubTopic1, String(tds1).c_str());
    Serial.println("已推播到MQTT Broker");
    MQTTLastPublishTime = millis(); //更新最後傳輸時間
  }
  MQTTClient.loop();//更新訂閱狀態
  delay(50);
}

//開始WiFi連線
void WifiConnecte() {
  //開始WiFi連線
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("WiFi連線成功");
  Serial.print("IP Address:");
  Serial.println(WiFi.localIP());
}

//開始MQTT連線
void MQTTConnecte() {
  MQTTClient.setServer(MQTTServer, MQTTPort);
  while (!MQTTClient.connected()) {
    //以亂數為ClietID
    String  MQTTClientid = "esp32-" + String(random(1000000, 9999999));
    if (MQTTClient.connect(MQTTClientid.c_str(), MQTTUser, MQTTPassword)) {
      //連結成功，顯示「已連線」。
      Serial.println("MQTT已連線");

    } else {
      //若連線不成功，則顯示錯誤訊息，並重新連線
      Serial.print("MQTT連線失敗,狀態碼=");
      Serial.println(MQTTClient.state());
      Serial.println("五秒後重新連線");
      delay(5000);
    }
  }
}```