HTTP GET Requests ESP8266

I’m using Esp8266 and XAMPP on macbook.

I can’t get string from PHP page. :’(

code esp

// Load Wi-Fi library
#include <ESP8266WiFi.h>
#include "Arduino.h"
#include "PCF8574.h"
#include <ESP8266HTTPClient.h>
#include <Wire.h>
 
//Access point credentials
const char* ssid = "Barney";
const char* pwd = "Stinson555";
const char* host = "http://192.168.64.2";
String get_host = "http://192.168.64.2";
 
WiFiServer server(80);  // open port 80 for server connection
 
void setup() 
{
  Serial.begin(115200); //initialise the serial communication
  delay(20);
  WiFi.begin(ssid, pwd);
    //starting the server
    server.begin();
 
}
void loop()
{
  get_device_status("home_light","Home Light");
  get_device_status("shop_light","Shop Light");
       
}
void get_device_status(String device_name, String device_text)
  {   
   WiFiClient client = server.available(); 
        HTTPClient http;
        String url = get_host+"/temperature/get_status.php?device_name="+device_name;     
        http.begin(url);
        int httpCode = http.GET();
        Serial.println(httpCode); //1
        String payload = http.getString();
        Serial.println(payload); //null
        if(payload=="1")
        {
          Serial.println(device_text+" is ON");
        }
        else
        {
          Serial.println(device_text+" is Off");
          }
        http.end();
        delay(1000);
  
  }

run code

18:54:29.075 -> -1
18:54:29.075 -> 
18:54:29.075 -> Home Light is Off
18:54:35.100 -> -1
18:54:35.100 -> 
18:54:35.100 -> Shop Light is Off

PHP page
http://192.168.64.2/temperature/get_status.php?device_name=home_light
it shows ’ 1 '.

<?php
    
$servername = "localhost";
$username = "root";
$password = "";
$dbname = "device_status";



    $conn = new mysqli($servername, $username, $password,$dbname);
    
    
    $device_name    =   $_GET['device_name'];
    // Check connection
    if ($conn->connect_error) {
        die("Connection failed: " . $conn->connect_error);
    }
    
    $sql        =   "SELECT device_status FROM devices_status WHERE device_name='$device_name' LIMIT 1";
    $result     =   $conn->query($sql);
    $sql2        =   "SELECT device_status FROM devices_status WHERE device_name='home_light' LIMIT 1";
    //$result2     =   $conn->query($sql2);
    //echo strval($result2);

    if ($result->num_rows > 0) {
    
    while ($row = $result->fetch_assoc())
    {
        echo $row['device_status'];
    }
        
    } else {
        echo "Error:" . $sql . "
" . $conn->error;
    }
    
    $conn->close();
    
    
?>

DB

CREATE TABLE `devices_status` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `device_name` varchar(50) DEFAULT NULL,
  `device_status` varchar(1) DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=3 DEFAULT CHARSET=latin1;

INSERT INTO `devices_status` VALUES ('1', 'home_light', '1');
INSERT INTO `devices_status` VALUES ('2', 'shop_light', '0');
#include <ESP8266WiFi.h>

// Replace with your network credentials
const char* ssid     = "";
const char* password = "";

// Set web server port number to 80
WiFiServer server(80);

// Variable to store the HTTP request
String header;

// Auxiliar variables to store the current output state
String output5State = "off";
String output4State = "off";

// Assign output variables to GPIO pins
const int output5 = 5;
const int output4 = 4;

void setup() {
  Serial.begin(115200);
  // Initialize the output variables as outputs
  pinMode(output5, OUTPUT);
  pinMode(output4, OUTPUT);
  // Set outputs to LOW
  digitalWrite(output5, LOW);
  digitalWrite(output4, LOW);

  // Connect to Wi-Fi network with SSID and password
  Serial.print("Connecting to ");
  Serial.println(ssid);
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  // Print local IP address and start web server
  Serial.println("");
  Serial.println("WiFi connected.");
  Serial.println("IP address: ");
  Serial.println(WiFi.localIP());
  server.begin();
}

void loop(){
  WiFiClient client = server.available();   // Listen for incoming clients

  if (client) {                             // If a new client connects,
    Serial.println("New Client.");          // print a message out in the serial port
    String currentLine = "";                // make a String to hold incoming data from the client
    while (client.connected()) {            // loop while the client's connected
      if (client.available()) {             // if there's bytes to read from the client,
        char c = client.read();             // read a byte, then
        Serial.write(c);                    // print it out the serial monitor
        header += c;
        if (c == '\n') {                    // if the byte is a newline character
          // if the current line is blank, you got two newline characters in a row.
          // that's the end of the client HTTP request, so send a response:
          if (currentLine.length() == 0) {
            // HTTP headers always start with a response code (e.g. HTTP/1.1 200 OK)
            // and a content-type so the client knows what's coming, then a blank line:
            client.println("HTTP/1.1 200 OK");
            client.println("Content-type:text/html");
            client.println("Connection: close");
            client.println();
            
            // turns the GPIOs on and off
            if (header.indexOf("GET /5/on") >= 0) {
              Serial.println("GPIO 5 on");
              output5State = "on";
              digitalWrite(output5, HIGH);
            } else if (header.indexOf("GET /5/off") >= 0) {
              Serial.println("GPIO 5 off");
              output5State = "off";
              digitalWrite(output5, LOW);
            } else if (header.indexOf("GET /4/on") >= 0) {
              Serial.println("GPIO 4 on");
              output4State = "on";
              digitalWrite(output4, HIGH);
            } else if (header.indexOf("GET /4/off") >= 0) {
              Serial.println("GPIO 4 off");
              output4State = "off";
              digitalWrite(output4, LOW);
            }
            
            // Display the HTML web page
            client.println("<!DOCTYPE html><html>");
            client.println("<head><meta name=\"viewport\" content=\"width=device-width, initial-scale=1\">");
            client.println("<link rel=\"icon\" href=\"data:,\">");
            // CSS to style the on/off buttons 
            // Feel free to change the background-color and font-size attributes to fit your preferences
            client.println("<style>html { font-family: Helvetica; display: inline-block; margin: 0px auto; text-align: center;}");
            client.println(".button { background-color: #195B6A; border: none; color: white; padding: 16px 40px;");
            client.println("text-decoration: none; font-size: 30px; margin: 2px; cursor: pointer;}");
            client.println(".button2 {background-color: #77878A;}</style></head>");
            
            // Web Page Heading
            client.println("<body><h1>ESP8266 Web Server</h1>");
            
            // Display current state, and ON/OFF buttons for GPIO 5  
            client.println("<p>GPIO 5 - State " + output5State + "</p>");
            // If the output5State is off, it displays the ON button       
            if (output5State=="off") {
              client.println("<p><a href=\"/5/on\"><button class=\"button\">ON</button></a></p>");
            } else {
              client.println("<p><a href=\"/5/off\"><button class=\"button button2\">OFF</button></a></p>");
            } 
               
            // Display current state, and ON/OFF buttons for GPIO 4  
            client.println("<p>GPIO 4 - State " + output4State + "</p>");
            // If the output4State is off, it displays the ON button       
            if (output4State=="off") {
              client.println("<p><a href=\"/4/on\"><button class=\"button\">ON</button></a></p>");
            } else {
              client.println("<p><a href=\"/4/off\"><button class=\"button button2\">OFF</button></a></p>");
            }
            client.println("</body></html>");
            
            // The HTTP response ends with another blank line
            client.println();
            // Break out of the while loop
            break;
          } else { // if you got a newline, then clear currentLine
            currentLine = "";
          }
        } else if (c != '\r') {  // if you got anything else but a carriage return character,
          currentLine += c;      // add it to the end of the currentLine
        }
      }
    }
    // Clear the header variable
    header = "";
    // Close the connection
    client.stop();
    Serial.println("Client disconnected.");
    Serial.println("");
  }
}

This code similar to you want.

Mrtian2:

#include <ESP8266WiFi.h>

// Replace with your network credentials
const char* ssid    = “”;
const char* password = “”;

// Set web server port number to 80
WiFiServer server(80);

// Variable to store the HTTP request
String header;

// Auxiliar variables to store the current output state
String output5State = “off”;
String output4State = “off”;

// Assign output variables to GPIO pins
const int output5 = 5;
const int output4 = 4;

void setup() {
  Serial.begin(115200);
  // Initialize the output variables as outputs
  pinMode(output5, OUTPUT);
  pinMode(output4, OUTPUT);
  // Set outputs to LOW
  digitalWrite(output5, LOW);
  digitalWrite(output4, LOW);

// Connect to Wi-Fi network with SSID and password
  Serial.print(“Connecting to “);
  Serial.println(ssid);
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(”.”);
  }
  // Print local IP address and start web server
  Serial.println("");
  Serial.println(“WiFi connected.”);
  Serial.println("IP address: ");
  Serial.println(WiFi.localIP());
  server.begin();
}

void loop(){
  WiFiClient client = server.available();  // Listen for incoming clients

if (client) {                            // If a new client connects,
    Serial.println(“New Client.”);          // print a message out in the serial port
    String currentLine = “”;                // make a String to hold incoming data from the client
    while (client.connected()) {            // loop while the client’s connected
      if (client.available()) {            // if there’s bytes to read from the client,
        char c = client.read();            // read a byte, then
        Serial.write(c);                    // print it out the serial monitor
        header += c;
        if (c == ‘\n’) {                    // if the byte is a newline character
          // if the current line is blank, you got two newline characters in a row.
          // that’s the end of the client HTTP request, so send a response:
          if (currentLine.length() == 0) {
            // HTTP headers always start with a response code (e.g. HTTP/1.1 200 OK)
            // and a content-type so the client knows what’s coming, then a blank line:
            client.println(“HTTP/1.1 200 OK”);
            client.println(“Content-type:text/html”);
            client.println(“Connection: close”);
            client.println();
           
            // turns the GPIOs on and off
            if (header.indexOf(“GET /5/on”) >= 0) {
              Serial.println(“GPIO 5 on”);
              output5State = “on”;
              digitalWrite(output5, HIGH);
            } else if (header.indexOf(“GET /5/off”) >= 0) {
              Serial.println(“GPIO 5 off”);
              output5State = “off”;
              digitalWrite(output5, LOW);
            } else if (header.indexOf(“GET /4/on”) >= 0) {
              Serial.println(“GPIO 4 on”);
              output4State = “on”;
              digitalWrite(output4, HIGH);
            } else if (header.indexOf(“GET /4/off”) >= 0) {
              Serial.println(“GPIO 4 off”);
              output4State = “off”;
              digitalWrite(output4, LOW);
            }
           
            // Display the HTML web page
            client.println("");
            client.println("<meta name=“viewport” content=“width=device-width, initial-scale=1”>");
            client.println("<link rel=“icon” href=“data:,”>");
            // CSS to style the on/off buttons
            // Feel free to change the background-color and font-size attributes to fit your preferences
            client.println(“html { font-family: Helvetica; display: inline-block; margin: 0px auto; text-align: center;}”);
            client.println(".button { background-color: #195B6A; border: none; color: white; padding: 16px 40px;");
            client.println(“text-decoration: none; font-size: 30px; margin: 2px; cursor: pointer;}”);
            client.println(".button2 {background-color: #77878A;}");
           
            // Web Page Heading
            client.println(“

ESP8266 Web Server

”);
           
            // Display current state, and ON/OFF buttons for GPIO 5 
            client.println(“

GPIO 5 - State " + output5State + “

”);
            // If the output5State is off, it displays the ON button     
            if (output5State==“off”) {
              client.println(”

<a href="/5/on"><button class=“button”>ON

");
            } else {
              client.println("

<a href="/5/off"><button class=“button button2”>OFF

");
            }
             
            // Display current state, and ON/OFF buttons for GPIO 4 
            client.println(“

GPIO 4 - State " + output4State + “

”);
            // If the output4State is off, it displays the ON button     
            if (output4State==“off”) {
              client.println(”

<a href="/4/on"><button class=“button”>ON

");
            } else {
              client.println("

<a href="/4/off"><button class=“button button2”>OFF

");
            }
            client.println("");
           
            // The HTTP response ends with another blank line
            client.println();
            // Break out of the while loop
            break;
          } else { // if you got a newline, then clear currentLine
            currentLine = “”;
          }
        } else if (c != ‘\r’) {  // if you got anything else but a carriage return character,
          currentLine += c;      // add it to the end of the currentLine
        }
      }
    }
    // Clear the header variable
    header = “”;
    // Close the connection
    client.stop();
    Serial.println(“Client disconnected.”);
    Serial.println("");
  }
}





This code similar to you want.

how can I get value from database.

there is another way to get value from the database?

:cry:

        String url = get_host+"/temperature/get_status.php?device_name="+device_name;

What IS in url?

        Serial.println(httpCode); //1

Anonymous printing sucks.

That comment is completely useless.