.. _Ext_Web_Control_Relay:
Web Control Relay (Station Mode)
================================
Overview
---------------
In this Article we are going to make a very useful and very easy home-automation project.
And for making of this home-automation system, we don't required any kind Internet and IOT Platform like blynk, ESP-Rainmeker, Arduino IOT Cloud.
We need only a Router or hotspot for making a local server, here router will work as a bridge between web-page and Arduino UNO R4 WIFI board.
.. image:: img/Web_Control_Realy.png
:align: center
:width: 80%
Wiring
----------------------
.. note::
In the experiment, a relay is used to control the closing and opening of a 5mm LED. If you have enough experience and knowledge in using electricity, you can try to control the lighting bulb with a relay while ensuring safety.
.. image:: img/Web_Control_Realy_Wiring.png
:align: center
:width: 70%
.. image:: img/Web_Control_Realy_Wiring.png
:align: center
:width: 80%
1. Upload the code
----------------------
Open the ``18_Web_Control_Relay`` file under the path of ``Basic-Starter-Kit-for-Arduino-Uno-R4-WiFi-main\Code``, or copy this code into **Arduino IDE**.
.. note::
Wi-Fi® support is enabled via the built-in ``WiFiS3`` library that is shipped with the Arduino UNO R4 Core. Installing the core automatically installs the ``WiFiS3`` library.
You still need to create or modify ``arduino_secrets.h``, replace ``SECRET_SSID`` and ``SECRET_PASS`` with the name and password of your home router WiFi access point. The file should contain:
.. code:: arduino
//arduino_secrets.h header file
#define SECRET_SSID "yournetwork"
#define SECRET_PASS "yourpassword"
.. note::
After uploading the code, check the IP address of UNO R4's Wifi in the serial monitor of Arduino IDE.
.. image:: img/Web_Control_Realy_Code.png
:align: center
:width: 100%
Then use your mobile phone to connect to your home router's WiFi (the mobile phone and UNO R4 are connected to the same LAN), and access the returned IP address in the serial monitor in the mobile browser. The browser will get the control page.
.. image:: img/Web_Control_Realy_Code1.png
:align: center
:width: 60%
2. Code explanation
----------------------
#. Importing Required Libraries
Importing the ``Arduino_LED_Matrix`` library for controlling LED matrix, ``WiFiS3`` library for WiFi functionalities, and ``arduino_secrets.h`` for sensitive data like passwords.
.. code-block:: arduino
#include "Arduino_LED_Matrix.h"
#include "WiFiS3.h"
#include "arduino_secrets.h"
#. Configuration and Variable Initialization
Define WiFi SSID, password, key index, LED pins, WiFi status, and create a WiFi server.
.. code-block:: arduino
#define LED1 7
#define LED2 8
char ssid[] = SECRET_SSID;
char pass[] = SECRET_PASS;
int keyIndex = 0;
int status = WL_IDLE_STATUS;
WiFiServer server(80);
#. ``setup()`` Function
Initialize serial communication, configure the WiFi module, start the server, and initialize LED pins.
.. code-block:: arduino
void setup() {
Serial.begin(9600);
matrix.begin();
pinMode(LED1, OUTPUT);
pinMode(LED2, OUTPUT);
digitalWrite(LED1, HIGH);
digitalWrite(LED2, HIGH);
if (WiFi.status() == WL_NO_MODULE) {
Serial.println("Communication with WiFi module failed!");
while (true);
}
String fv = WiFi.firmwareVersion();
if (fv < WIFI_FIRMWARE_LATEST_VERSION) {
Serial.println("Please upgrade the firmware");
}
while (status != WL_CONNECTED) {
Serial.print("Network named: ");
Serial.println(ssid);
status = WiFi.begin(ssid, pass);
delay(10000);
}
server.begin();
printWifiStatus();
}
#. Main ``loop()`` Function
The ``loop()`` function performs two key operations: running the web server and updating the LED matrix.
.. code-block:: arduino
void loop() {
webServer();
LEDMatrix();
}
#. ``LEDMatrix()`` Function
Load a frame to the LED matrix.
.. code-block:: arduino
void LEDMatrix() {
matrix.loadFrame(hi);
}
#. ``webServer()`` Function
Listen for incoming clients, parse their requests, and control LEDs based on the received commands.
.. code-block:: arduino
void webServer() {
WiFiClient client = server.available();
if (client) {
Serial.println("New Client.");
String currentLine = "";
currentTime = millis();
previousTime = currentTime;
while (client.connected() && currentTime - previousTime <= timeoutTime) {
currentTime = millis();
if (client.available()) {
char c = client.read();
Serial.write(c);
header += c;
if (c == '\n') {
if (currentLine.length() == 0) {
client.println("HTTP/1.1 200 OK");
client.println("Content-type:text/html");
client.println("Connection: close");
client.println();
if (header.indexOf("GET /ledon1") >= 0) {
output1 = "on";
digitalWrite(LED1, LOW);
} else if (header.indexOf("GET /ledoff1") >= 0) {
output1 = "off";
digitalWrite(LED1, HIGH);
}
if (header.indexOf("GET /ledon2") >= 0) {
output2 = "on";
digitalWrite(LED2, LOW);
} else if (header.indexOf("GET /ledoff2") >= 0) {
output2 = "off";
digitalWrite(LED2, HIGH);
}
client.println("");
client.println("");
client.println("");
client.println("");
client.println("
Web Relay Control
");
client.println("
Relay1 " + output1 + "
");
if (output1 == "off") {
client.println("
");
} else {
client.println("
");
}
client.println("
Relay2 " + output2 + "
");
if (output2 == "off") {
client.println("
");
} else {
client.println("
");
}
client.println("");
client.println();
break;
} else {
currentLine = "";
}
} else if (c != '\r') {
currentLine += c;
}
}
}
header = "";
client.stop();
Serial.println("Client disconnected.");
Serial.println("");
}
}
#. ``printWifiStatus()`` Function
Print the current WiFi status, including SSID, IP address, and signal strength.
.. code-block:: arduino
void printWifiStatus() {
Serial.print("SSID: ");
Serial.println(WiFi.SSID());
IPAddress ip = WiFi.localIP();
Serial.print("IP Address: ");
Serial.println(ip);
long rssi = WiFi.RSSI();
Serial.print("signal strength (RSSI):");
Serial.print(rssi);
Serial.println(" dBm");
Serial.print("Now open this URL on your browser --> http://");
Serial.println(ip);
}