如何将数据从nodemcu esp8266发送到xampp databse

Question

将代码上传到nodemcu esp82366时出现错误，我无法理解错误是什么。

我第一次上传代码时，会发生确切的错误。

第二次我上传的代码是成功的代码（我对代码进行了一些修改，这是火灾危险的声明和公式）。

然后我上传确切的代码（更新后的代码是在if语句中添加了“ indexVal”，并且在同一部分出现了相同的错误。

您能帮我解决我的问题吗？

对不起，我的英语。

dht11.ino

#include "DHT.h"
#include <ESP8266WiFi.h>
#include <WiFiClient.h>
#include <ESP8266WebServer.h>
#include <ESP8266mDNS.h>
#include <SPI.h>


#define DHTPIN D2

#define DHTTYPE DHT11

DHT dht(DHTPIN,DHTTYPE);


float humidityData;
float temperatureData;

const char* ssid = "icecream@unifi";// 
const char* password = "ilovechocolate";

char server1[] = "192.168.x.x";   

WiFiServer server(80);
WiFiClient client;    


void setup()
{
 Serial.begin(115200);
  delay(10);
  dht.begin();
  // Connect to WiFi network
  Serial.println();
  Serial.println();
  Serial.print("Connecting to ");
  Serial.println(ssid);

  WiFi.begin(ssid, password);

  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("");
  Serial.println("WiFi connected");

  // Start the server
  server.begin();
  Serial.println("Server started");
  Serial.print(WiFi.localIP());
  delay(1000);
  Serial.println("connecting...");
 }


void loop()
{ 
  humidityData = dht.readHumidity();
  temperatureData = dht.readTemperature(); 

  Sending_To_phpmyadmindatabase(); 
  delay(20000); // interval
 }


 void Sending_To_phpmyadmindatabase()   //CONNECTING WITH MYSQL
 { 

   if (client.connect(server1, 80))
   {

      //Fire risk based on Angstrom Index
        String stat1 = "Low";
        String stat2 = "Moderate";
        String stat3 = "High";
        String stat4 = "Very High";
        String stat5 = "Extreme";

//Formula to determine the fire risk using Angstrom Index
      float indexVal = (humidityData/20) + ((27-temperatureData)/10);

      Serial.println("connected");
      // Make a HTTP request:
      Serial.print("GET /mdff/insertsensor1.php?humidity=");
      client.print("GET /mdff/insertsensor1.php?humidity=");     //YOUR URL
      Serial.println(humidityData);
      client.print(humidityData);

      client.print("&temperature=");
      Serial.println("&temperature=");
      client.print(temperatureData);
      Serial.println(temperatureData);

      //Angstrom Index
      if(indexVal >= 4.0)
      {
        client.print("&index=");
        Serial.println("&index=");
        client.print(indexVal);
        Serial.println(indexVal);

        client.print("&status=");
        Serial.println("&status=");
        client.print(stat1);
        Serial.println(stat1);  
      }
      else if ((index <= 3.0) || (index >= 4.0))
      {
        client.print("&index=");
        Serial.println("&index=");
        client.print(indexVal);
        Serial.println(indexVal);

        client.print("&status=");
        Serial.println("&status=");
        client.print(stat2);
        Serial.println(stat2);
      }
      else if ((index <= 2.5) || (index >= 3.0))
      {
        client.print("&index=");
        Serial.println("&index=");
        client.print(indexVal);
        Serial.println(indexVal);

        client.print("&status=");
        Serial.println("&status=");
        client.print(stat3);
        Serial.println(stat3);

      }
      else if ((index <= 2.0) || (index >= 2.5))
      {
        client.print("&index=");
        Serial.println("&index=");
        client.print(indexVal);
        Serial.println(indexVal);

        client.print("&status=");
        Serial.println("&status=");
        client.print(stat4);
        Serial.println(stat4);

      }
      else if (index <= 2.0)
      {
        client.print("&index=");
        Serial.println("&index=");
        client.print(indexVal);
        Serial.println(indexVal);

        client.print("&status=");
        Serial.println("&status=");
        client.print(stat5);
        Serial.println(stat5);

      }

    client.print(" ");      //SPACE BEFORE HTTP/1.1
    client.print("HTTP/1.1");
    client.println();
    client.println("Host: 192.168.x.x");
    client.println("Connection: close");
    client.println();
  } 
  else 
  {
    // if you didn't get a connection to the server:
    Serial.println("connection failed");
  }
 }

编译代码时出现错误：

exit status 1
invalid operands of types 'char*(const char*, int)' and 'double' to binary 'operator<='

此部分指出的错误：

else if ((index <= 2.5) || (index >= 3.0))

 else if ((index <= 2.0) || (index >= 2.5))