Controlling Wifi Devices with Flutter-Dart

Controlling Wifi Devices with Flutter-Dart

Mobile Programming   Apr 7, 2023  Add to Reading List

In this article, we will examine how to send control commands to a microcontroller connected to a Wifi module with the Flutter-Dart programming language. But first, let's give some examples of Wifi-based control applications:

Here are some sample applications from Wi-Fi controlled home devices:


Smart thermostats: These devices allow you to control the home's heating and cooling systems via Wi-Fi. In this way, you can remotely control the temperature of your home and save energy.

Smart lighting: These devices allow you to change your lighting patterns by controlling your home over Wi-Fi. This provides functions such as turning your lights on, off or adjusting their brightness.

Smart security cameras: These devices allow you to monitor your home remotely via Wi-Fi. This way you can use a smartphone or tablet to monitor your home from anywhere.

Smart door lock: These devices allow you to lock and unlock your home door via Wi-Fi. In this way, you can access your door remotely and let your guests in.

Smart sockets: These devices allow you to control your sockets via Wi-Fi. In this way, you can use a smartphone or tablet from anywhere to turn your sockets on or off.

These examples can be multiplied further.

Let's examine the codes on the Flutter-Dart codes side. Let's examine the codes with a simple code without going into visual widgets. You can send HTTP GET requests to the ESP 12f Wifi module using an example Flutter code as below. This code sample uses the IP address and port 80 of the ESP 12f module as the web server and sends simple commands such as on and off. Of course, commands like these "open" and "close" can be duplicated.

 

import 'package:http/http.dart' as http;

void main() {

  turnOn(); // send data to ESP 12f

  turnOff(); // send data to ESP 12f

}

 

void turnOn() async {

  var response = await http.get('http://ESP_12f_IP_adrs:80/on');

  if (response.statusCode == 200) {

    print('ESP 12f open');

  } else {

    print('Hata: ${response.statusCode}');

  }

}

 

void turnOff() async {

  var response = await http.get('http://ESP_12f_IP_adrs:80/off');

  if (response.statusCode == 200) {

    print('ESP 12f closed');

  } else {

    print('Hata: ${response.statusCode}');

  }

}

You may need to change the IP address of the ESP 12f module depending on the network where your code will run. This code sends commands to the web server of the ESP 12f module by sending HTTP GET requests and receives an HTTP status code in response. You can adapt your code to send specific commands of your ESP 12f module.
On the microcontroller side, there is an ESp 12f wifi module. Below are the sample codes that we will try with Arduino. The code example will create a web server that detects incoming requests via the ESP 12f WiFi module and writes the incoming data to the serial port. We can print these commands, which we receive as strings, to the serial port as well as use them to run other functions within "if" command blocks:

 

#include <ESP8266WiFi.h>

#include <WiFiClient.h>

const char* ssid = "Wifi_SSID"; // WiFi net SSID

const char* password = "Wifi_şifresi"; // WiFi password

WiFiServer server(80); // Web server port number

 

void setup() {

  Serial.begin(9600); // Serial port için baud rate

  delay(10);

 

  // WiFi connect

  WiFi.begin(ssid, password);

  while (WiFi.status() != WL_CONNECTED) {

    delay(1000);

    Serial.println("WiFi connecting...");

  }

 

  Serial.println("WiFi connected.");

 

  // Web server open port

  server.begin();

  Serial.println("Web server started.");

}

 

void loop() {

  // new request controlling

  WiFiClient client = server.available();

  if (!client) {

    return;

  }

 

  // on request, arrived data

  Serial.println("new request!.");

  while (client.connected()) {

    if (client.available()) {

      String request = client.readStringUntil('\r');

      Serial.println(request);

    }

  }

 

  // close

  client.stop();

  Serial.println("closed.");

}

Creates a web server using the ESP 12f WiFi module. The Arduino board works as a web server and receives incoming requests. Requests are written to the serial port and then the connection is closed. Using this code, you can follow the requests from the ESP 12f module over the serial port.

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