Controlling devices with esp32 integrated with web site

 

ESP32 IoT Project

Overview

This project demonstrates how to manage Wi-Fi connections and interact with a server using an ESP32. The goal is to provide an efficient solution for handling dynamic Wi-Fi connections and device control through HTTP requests. We also include methods for resetting Wi-Fi credentials and troubleshooting common issues.

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Wi-Fi Manager with AutoConnect and Reset Option

The ESP32 uses the WiFiManager library to simplify the Wi-Fi setup process. The following code demonstrates how to enable AutoConnect with an option to reset the Wi-Fi settings by holding a button for more than two seconds.

Example Code

#include <WiFiManager.h>  // https://github.com/tzapu/WiFiManager
#include <WiFi.h>
#include <WebServer.h>
#include <HTTPClient.h>
#include <ArduinoJson.h>

// Replace with the server URL
const char* serverURL = "http://your-server.local/ESP32_MySql_Database/Final/get_device_status.php";

int ledPin = 2;  // GPIO for the LED
int devicePins[] = {2, 4, 5};  // Array to control multiple devices (one GPIO per device)
int resetButtonPin = 0;  // GPIO pin for reset button
unsigned long buttonPressTime = 0;
bool resetWiFi = false;

void setup() {
    Serial.begin(115200);

    // Initialize reset button pin
    pinMode(resetButtonPin, INPUT_PULLUP);

    // Check if reset button is held down
    if (digitalRead(resetButtonPin) == LOW) {
        buttonPressTime = millis();
        while (digitalRead(resetButtonPin) == LOW) {
            if (millis() - buttonPressTime > 2000) {
                resetWiFi = true;
                break;
            }
        }
    }

    // Initialize WiFiManager
    WiFiManager wm;
    if (resetWiFi) {
        wm.resetSettings();  // Reset Wi-Fi settings
        Serial.println("Wi-Fi settings reset. Restarting...");
        ESP.restart();
    }

    // Attempt to auto-connect to WiFi with WiFiManager
    bool res = wm.autoConnect("AutoConnectAP", "password"); // AP name and password

    if (!res) {
        Serial.println("Failed to connect to Wi-Fi");
        ESP.restart();
    } else {
        Serial.println("Connected to Wi-Fi!");
    }

    // Initialize device pins
    for (int pin : devicePins) {
        pinMode(pin, OUTPUT);
        digitalWrite(pin, LOW);
    }
}

void loop() {
    // Ensure Wi-Fi is still connected
    if (WiFi.status() == WL_CONNECTED) {
        HTTPClient http;
        http.begin(serverURL);
        int httpResponseCode = http.GET();

        if (httpResponseCode == 200) {
            String response = http.getString();
            Serial.println("Received response:");
            Serial.println(response);

            // Parse JSON
            DynamicJsonDocument doc(1024);
            deserializeJson(doc, response);

            // Control each device based on the JSON response
            for (JsonObject device : doc.as<JsonArray>()) {
                int id = device["id"];
                int status = device["status"];

                // Control devices within devicePins array bounds
                if (id <= sizeof(devicePins) / sizeof(devicePins[0])) {
                    digitalWrite(devicePins[id - 1], status == 1 ? HIGH : LOW);
                    Serial.print("Device ");
                    Serial.print(id);
                    Serial.print(" Status: ");
                    Serial.println(status == 1 ? "ON" : "OFF");
                }
            }
        } else {
            Serial.print("Error code: ");
            Serial.println(httpResponseCode);
        }
        http.end();
    } else {
        Serial.println("Wi-Fi not connected");
    }

    delay(5000);  // Check every 5 seconds
}

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PHP Script for Server-Side Handling

The server-side PHP script handles incoming HTTP requests and returns the status of connected devices as JSON. Below is an example of a PHP script to interact with the database and return device status:

Example PHP Code

<?php
$servername = "localhost";
$username = "root";
$password = "";
$dbname = "esp32_database";

// Create connection
$conn = new mysqli($servername, $username, $password, $dbname);

// Check connection
if ($conn->connect_error) {
    die("Connection failed: " . $conn->connect_error);
}

$sql = "SELECT id, status FROM devices";
$result = $conn->query($sql);

if ($result->num_rows > 0) {
    $devices = array();

    while ($row = $result->fetch_assoc()) {
        $devices[] = $row;
    }

    header('Content-Type: application/json');
    echo json_encode($devices);
} else {
    echo "[]";  // Empty JSON array if no data is found
}

$conn->close();
?>

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Working Video:

Troubleshooting Tips

• Ensure the ESP32 and server are on the same network.

• Use the actual IP address of the server if http://mycomputer.local does not resolve.

• Verify that the PHP script is hosted correctly on the server (e.g., using XAMPP or a similar tool).

• Check for any firewall or network restrictions.