Hello, i'm University student, and i want to make my final year project.
i'm making a smart locker using Raspberry Pi as main processor and database storage, WeMos D1 mini using arduino programming as locker sub processor to control solenoid, and input limit switch.
and my question is, how to make WeMos to get data from database?
ex : the database have 1 table consist of 4 row ( date, barcode, locker number*, locker status**)
it's used for knowing which locker should be lock or unlock
** it's used to control solenoid of the choosen locker, (on= unlock/off(lock))
it's like, when the database showing locker number 3 and the status is on, then WeMos will continuously check the status of locker number 3. if the status is ON the WeMos will control solenoid to unlock
oh yeah, i'm using local area network over wifi for the media, and not using internet
still dont get it
by anychance is that Get HTTP using internet?
what i'm still confused is how to use arduino to get data from phpmyadmin/ mysql database
#include <ESP8266WiFi.h>
#include <ESP8266mDNS.h>
#include <WiFiUdp.h>
const char* ssid = "WS Elektro"; //!!!!!!!!!!!!!!!!!!!!! modify this
const char* password = "workshop525"; //!!!!!!!!!!!!!!!!!!!!!modify this
int ledPin = D4; //connect led pin to d4 and ground
int intensitas = 0;
WiFiServer server(80);
void setup() {
Serial.begin(115200);
delay(10);
pinMode(ledPin, OUTPUT);
digitalWrite(ledPin, LOW);
// Connect to WiFi network
Serial.println();
Serial.println();
Serial.print("Connecting to ");
Serial.println(ssid);
WiFi.mode(WIFI_STA);
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");
// Print the IP address
Serial.print("Use this URL : ");
Serial.print("http://");
Serial.print(WiFi.localIP());
Serial.println("/");
}
void loop() {
// Check if a client has connected
WiFiClient client = server.available();
if (!client) {
return;
}
// Wait until the client sends some data
Serial.println("new client");
while(!client.available()){
delay(1);
}
// Read the first line of the request
String request = client.readStringUntil('\r');
Serial.println(request);
client.flush();
// Match the request
int value = LOW;
if (request.indexOf("/LED=ON") != -1) { // request.indexOf = cari char atau string dalam string, -1 = tidak ditemukan
if(intensitas >= 255)
intensitas = 255;
else
intensitas+=20;
analogWrite(ledPin, intensitas);
value = HIGH;
}
if (request.indexOf("/LED=OFF") != -1){
if(intensitas <= 0)
{ intensitas = 0;}
else
intensitas-=20;
analogWrite(ledPin, intensitas);
value = LOW;
}
// Return the response
client.println("HTTP/1.1 200 OK");
client.println("Content-Type: text/html");
client.println(""); // do not forget this one
client.println("<!DOCTYPE HTML>");
client.println("<?php");
client.println("$db = mysqli_connect('localhost','root','root','coba')");
client.print ("or die('Error connecting to MySQL server.')");
client.println("<html>");
client.println("<head>");
client.println("</head>");
client.println("<body>");
client.println("<h1>PHP connect to MySQL</h1>");
client.println("<?php>");
client.println("$query = 'SELECT * FROM test'");
client.println("\n");
client.println("mysqli_query($db, $query) or die('Error querying database.')");
client.println("$result = mysqli_query($db, $query)");
client.println("$row = mysqli_fetch_array($result)");
client.println("while ($row = mysqli_fetch_array($result))");
client.print ("{echo $row['first_name'] . ' ' . $row['last_name'] . ': ' . $row['email'] . ' ' . $row['city'] .'
'}");
client.println("mysqli_close($db)");
client.println("?>");
client.println("</body>");
client.print("Led pin is now: ");
if(value == HIGH) {
client.print("On");
} else {
client.print("Off");
}
client.println("
");
client.println("Click <a href=\"/LED=ON\">here</a> turn the LED on pin 4 ON
");
client.println("Click <a href=\"/LED=OFF\">here</a> turn the LED on pin 4 OFF
");
client.println("</html>");
delay(1);
Serial.println("Client disconnected");
Serial.println("");
}
this is my code from the basic wifi control LED using html code
what i was doing is writing html code into arduino. i thought writing it will make html get data from mysql database using php
what i'm still confused is how to use arduino to get data from phpmyadmin/ mysql database
Until you understand the differences by the php scripr, phpmyadmin, and the database, you probably never will get it.
One of the reasons that php and MySQL are usually installed together is that php has a bunch of functionality that makes it easy to get data from, or insert data into (a table in) a MySQL database.
So, eat the pie, and put the toys away for now.
Learn how to write a php script ON YOUR PC that can get data out of a table in your MySQL database.
Learn how to invoke that php script from a browser. A hint: the browser makes a GET request (but you don't see that happening) and reads the server response.
Now, go to another PC in the same local area network, and invoke that php script from a browser.
ONLY after you can successfully do that should you even consider how to make the NOT-AN-ARDUINO do that.
Thankyou so much Pauls,
now i understand PHP, and how to collect the data and the server things.
I apreciate your opinion in telling me to learn those first xD.
and now my mission is almost accomplished,
now i get to know how to store data from database to a string in arduino.
so im trying to encode data that i want from database in PHP code.
then i'll try to decode it in arduino so i can output it into controlling my solenoid for lock and unlock
