Sending sensor data to localhost using IoT development board esp8266-12

Sending  sensor data to localhost  using IoT development board esp8266-12

In this article, I am going to show you how to send sensor sensor data to a local webserver using esp8266.

Before delving into this article , let me explain the term localhost.
Localhost refers to the local computer that a program is running on. For example, if you are running a Web browser on your computer, your computer is considered to be the "localhost".

The deliverables for this project are:

Xamp webserver download it here https://www.apachefriends.org/

Arduino IDE download here https://www.arduino.cc/

ESP8266 official website https://www.nodemcu.com/

Smartphone used as a router.

Project requirement: Create a folder in the xamp/htdocs named esp8266. In this folder you are going to save the postData.php and databaseConfig.php

To send the sensor data to a database, we need to write an arduino sketch using a TCP protocol to communicate wirelessly to the local webserver.

Let's get it done now!

Step 1: Install esp8266 board the link to the procedure can be found here https://randomnerdtutorials.com/how-to-install-esp8266-board-arduino-ide/

Step 2: The arduino sketch is shown below. I create two function connectWifi() and sendSensorData() which I invoke respectively in the void setup and void loop. If you are confused please look for a tutorial on basic arduino code.

#include <WiFiClient.h> 
#include <ESP8266WebServer.h>
#include <ESP8266HTTPClient.h>
const char *ssid = "MelleB";  //ENTER YOUR WIFI ssid
const char *password = "refj4497";  //ENTER YOUR WIFI password


void setup() {
connectWifi();
}


void loop() {
SendSensorData();
}
//function to connect to wifi
void connectWifi(){
  delay(1000);
  Serial.begin(115200);
  WiFi.mode(WIFI_OFF);        //Prevents reconnection issue (taking too long to connect)
  delay(1000);
  WiFi.mode(WIFI_STA);        //This line hides the viewing of ESP as wifi hotspot
  WiFi.begin(ssid, password);     //Connect to your WiFi router
  Serial.println("");
  Serial.print("Connecting");
  // Wait for connection
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  //If connection successful show IP address in serial monitor 
  Serial.print("Connected to ");
  Serial.println(ssid);
  Serial.print("IP address: ");
  Serial.println(WiFi.localIP());  //IP address assigned to your ESP
}


//function to send sensor data 
void SendSensorData() {
  HTTPClient http;    //Declare object of class HTTPClient
  String sensorData1,sensorData2,sensorData3,sensorData4,sensorData5,sensorData6,sensorData7, postData;
  sensorData1="High";
    sensorData2="High";
      sensorData3="High";
        sensorData4="High";
          sensorData5="High";
            sensorData6="High";
              sensorData7="High";
  //Post Data
  postData = "sensor1=" +  sensorData1 + "&sensor2=" + sensorData2+ "&sensor3=" + sensorData3+  "&sensor4=" + sensorData4+ "&sensor5=" + sensorData5+ "&sensor6=" + sensorData6+  "&sensor7=" + sensorData7;
  
  http.begin("http://192.168.43.142/esp8266/postData.php");              //change the ip to your computer ip address
  http.addHeader("Content-Type", "application/x-www-form-urlencoded");    //Specify content-type header
 
  int httpCode = http.POST(postData);   //Send the request
  String payload = http.getString();    //Get the response payload
 
  Serial.println(httpCode);   //Print HTTP return code
  Serial.println(payload);    //Print request response payload
 
  http.end();  //Close connection
  
  delay(5000);  //Post Data at every 5 seconds
}

Step 3: Create the database sensor and the table name logs and save it in the esp866 folder as databaseConfig.php

//connect to localhost if not exists
	$servername = "localhost";
	$username = "root";
	$password = "";


	// Create connection
	$conn = new mysqli($servername, $username, $password);
	// Check connection
	if ($conn->connect_error) {
	    die("Connection failed: " . $conn->connect_error);
	}


	// Create database
	$sql = "CREATE DATABASE sensor";
	
	    echo "Database created successfully";
	} else {
	    echo "Error creating database: " . $conn->error;
	}


	$conn->close();


	echo "<br>";
//Connect to database and create table
	$servername = "localhost";
	$username = "root";
	$password = "";
	$dbname = "sensor";


	// Create connection
	$conn = new mysqli($servername, $username, $password, $dbname);
	// Check connection
	if ($conn->connect_error) {
	    die("Connection failed: " . $conn->connect_error);
	}


	
	$sql = "CREATE TABLE logs (
	id INT(6) UNSIGNED AUTO_INCREMENT PRIMARY KEY,
	sensor1 VARCHAR(30),
	sensor2 VARCHAR(30),
    sensor3 VARCHAR(30),
	sensor4 VARCHAR(50),
	sensor5 VARCHAR(50),
	sensor6 VARCHAR(50),
	sensor7 VARCHAR(50),
	\`Date\` DATE NULL,
	\`Time\` TIME NULL, 
	\`TimeStamp\` TIMESTAMP NULL DEFAULT CURRENT\_TIMESTAMP ON UPDATE CURRENT\_TIMESTAMP)";


	if ($conn->query($sql) === TRUE) {
	    echo "Table logs created successfully";
	} else {
	    echo "Error creating table: " . $conn->error;
	}


	$conn->close();
?>

Step 4: Create postData.php in the esp866 folder and paste the code below in it.

//Creates new record as per request
    //Connect to database
    $servername = "localhost";
    $username = "root";
    $password = "";
    $dbname = "sensor";


    // Create connection
    $conn = new mysqli($servername, $username, $password, $dbname);
    // Check connection
    if ($conn->connect_error) {
        die("Database Connection failed: " . $conn->connect_error);
    }


    //Get current date and time
    date\_default\_timezone_set('Asia/Kolkata');
    $d = date("Y-m-d");
    //echo " Date:".$d."<BR>";
    $t = date("H:i:s");


    if(!empty($\_POST\['sensor1'\]) || !empty($\_POST\['sensor2'\]))
    {
    	$sensorData1 = $_POST\['sensor1'\];
    	$sensorData2 = $_POST\['sensor2'\];
		$sensorData3 = $_POST\['sensor3'\];
		$sensorData4 = $_POST\['sensor4'\];
		$sensorData5 = $_POST\['sensor5'\];
		$sensorData6 = $_POST\['sensor6'\];
		$sensorData7 = $_POST\['sensor7'\];


	    $sql = "INSERT INTO logs (sensor1, sensor2,sensor3,sensor4,sensor5,sensor6,sensor7, Date, Time) VALUES ('".$sensorData1."', '".$sensorData2."', '".$sensorData3."', '".$sensorData4."', '".$sensorData5."', '".$sensorData6."', '".$sensorData7."', '".$d."', '".$t."')";


		if ($conn->query($sql) === TRUE) {
		    echo "OK";
		} else {
		    echo "Error: " . $sql . "<br>" . $conn->error;
		}
	}




	$conn->close();
?>

Step 5: software testing

  • Open your web browser and type localhost/esp8266. Click on databaseConfig.php you should get a message data base sensor created successfully and do the same with postData.php. If you do not get any error message then you are good to go.
  • Open the serial monitor of your arduino and set the baud rate to 115200
  • The wifi ssid and ip address should display to the serial monitor
  • You should get a response 200 from the server and ok message
  • Check your database table you will get all the sensor table high, the date and time.
  • ** The output is shown below**

Please let me know in case of any errors.

PHP / MySQL - Count how many table in database contain Specific name

I'm building an admin to control an interactive game, and I'm using PHP/MySql to store all the data for all the rounds. Each of the tables that I want to load into the game via PHP are titled "Puzzle*" with the * being an incremental index number. There are a few other tables in my database for global game data and bonus rounds.

I'm building an admin to control an interactive game, and I'm using PHP/MySql to store all the data for all the rounds. Each of the tables that I want to load into the game via PHP are titled "Puzzle*" with the * being an incremental index number. There are a few other tables in my database for global game data and bonus rounds.

What I want to be able to do is count the number of tables in my database that contain the name "Puzzle", and then use that total number as a randomizer to select a puzzle randomly. I plan to have roughly 50 puzzles, so an automated way of selecting a random puzzle, and then if I want to select another puzzle - to remove that previous puzzle from the list so that there is no chance of it being repeated until I start the whole game over again.

MySQL Database

Database Name: puzzleGame
Table 1: puzzle1
Table 2: puzzle2
Table 3: puzzle3
Table 4: puzzle4
Table 5: globals
Table 6: bonus


PhP MySQL Projects

PhP MySQL Projects

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Description
PHP Projects in Urdu is a comprehensive course. It has five PHP projects in Urdu. Each project is created from scratch. You will get source code of each project as well. The list of 5 projects is as under:

Project 1: Find and Replace Application
Project 2: Building an Email Marketing Application
Project 3: Creating a Contact Form
Project 4: Building a Search Engine For Database
Project 5: Building a PHP Quiz Application
As this is an intermediate level course so it has some requisites as well

This is a Urdu/Hindi video course

Who this Course is for:

Anyone who wants to learn Web development
Who wants to become a PHP Developer
Basic knowledge
You must have basic knowledge about PHP and Mysql
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What will you learn
How to Find and Replace Application
How to Build an Email Marketing Application
How to Create a Contact Form
How to Build a Search Engine For Database
How to Build a PHP Quiz Application
To continue:

Inserting session array into mysql database

I am still learning bits of PHP and have been stuck on this issue regarding the POST data from radio buttons within a form being inserted into a mysql database from a session array. Currently, I have 2 questions within my survey and they consist of radio button options for a user to select from. The relevant answers can be selected and they are stored in a session array:

I am still learning bits of PHP and have been stuck on this issue regarding the POST data from radio buttons within a form being inserted into a mysql database from a session array. Currently, I have 2 questions within my survey and they consist of radio button options for a user to select from. The relevant answers can be selected and they are stored in a session array:

array(1) { ["choice"]=> array(2) { [0]=> string(11) "56-65 years" [1]=> string(17) "Prefer not to say" } }

However I was not too sure if the array should be as such. The two answers chosen from the radio options in the above example are "56-65 years" and "Prefer not to say".

Following on from the session array, I am trying to insert each of those answers in to a mysql database. I have a column created to insert each answer (i.e. there are two columns (question 1 and question 2) to store the two answers from the example above).

I am aware that my code is open to SQL injection and plan on fixing that after overcoming the inserting of data.

Question.php

     <form method="POST" action="process.php">
      <ul class="choices">
  &lt;?php while($row = $answers-&gt;fetch_assoc()):?&gt;
    &lt;li&gt;&lt;input type="radio" name="choice" value="&lt;?php echo $row['answerText']; ?&gt;"&gt;

    &lt;?php echo $row['answerText'] ?&gt;&lt;/li&gt;
    &lt;?php endWhile; ?&gt;

  &lt;/ul&gt; 
  &lt;input type="submit" name="submit" value="Next Question"&gt;
  &lt;input type="hidden" name="number" value="&lt;?php echo $number; ?&gt;"&gt;

</form>

Process.php

<?php

    if(isset($_POST['submit'])){

$number = $_POST['number'];
$next = $number+1;

$selected_choice = $_POST['choice'];
$_SESSION['choice'][] = $selected_choice;

foreach ($_SESSION['choice'] as $key) {

$user_responses = $key;

}

$insertdata = "INSERT INTO userAnswersTable('question1', 'question2') VALUES ($_SESSION['choice'])";
$resulting = $mysqli->query($insertdata) or die($mysqli->error.LINE);

}
?>

I would expect each of the user responses to be in an array from which each individual selected choice within the session array can be stored in each corresponding column within the mySql table. Any suggestions would be very helpful.