Haber Detay | Milivolt

Haberler Applications 220 Volt Lamp On-Off Application with Bluetooth

25.Feb.2023

We continue our Bluetooth applications. This application is similar to the previous Bluetooth led lighting application. This time we connected the pin to the relay input to light the LED and applied a 220 volt lamp on-off.

You can watch our youtube video about the application:

We coded the Android application withFlutter-Dart. There are three buttons on the application. One is the “Connect” button, the others are on and off buttons. On/off buttons send "on" and "off" information to the bluetooth module connected to Arduino on the bluetooth adapter. When the Arduino program receives this information, it turns the lamp on or off.

Below are the Flutter-Dart codes:

import 'dart:async';
//import 'dart:convert';

import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'package:flutter_bluetooth_serial/flutter_bluetooth_serial.dart';

void main()=> runApp(const MyApp());

class MyApp extends StatefulWidget {
const MyApp({super.key});

@override
// ignore: library_private_types_in_public_api
_MyAppState createState()=> _MyAppState();
}

class _MyAppState extends State<MyApp> {
List<BluetoothDevice> _devices=[];
late BluetoothConnection connection;
String adr="00:21:07:00:50:69"; // my bluetooth device MAC Adres

@override
void initState() {
super.initState();
_loadDevices();
}

Future<void> _loadDevices() async {
List<BluetoothDevice> devices=await FlutterBluetoothSerial.instance.getBondedDevices();

setState(() { _devices=devices; });
}
//----------------------------
Future<void> sendData(String data) async {

data=data.trim();
try {
List<int> list=data.codeUnits;
Uint8List bytes=Uint8List.fromList(list);
connection.output.add(bytes);
await connection.output.allSent;
if (kDebugMode) {
// print('Data sent successfully');
}
} catch (e) {
//print(e.toString());
}
}

@override
Widget build(BuildContext context) {
return MaterialApp(
home: Scaffold(
appBar: AppBar(
title: const Text("Bluetooth 220 Volt LAMP Control"),
),
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: [
const Text("MAC Adress: 00:21:07:00:50:69"),

ElevatedButton(child:Text("Connect"),onPressed: () {
connect(adr);

},),
SizedBox(height: 30.0,),

ElevatedButton(child:Text(" 220 VOLT OPEN "),onPressed: () {
sendData("on");

},),

SizedBox(height: 10.0,),
ElevatedButton(child:Text("220 VOLT CLOSE"),onPressed: () {
sendData("off");

},),
],
),
),

)

);
}

Future connect(String address) async {
try {
connection=await BluetoothConnection.toAddress(address);
sendData('111');
//durum="Connected to the device";
connection.input!.listen((Uint8List data) {
//Data entry point
// durum=ascii.decode(data);
});

} catch (exception) {
// durum="Cannot connect, exception occured";
}
}

// --------------**************data gonder
//Future send(Uint8List data) async {
//connection.output.add(data);
//await connection.output.allSent;
}
//------------*********** data gonder end

Arduino codes are below:

#include <SoftwareSerial.h>

SoftwareSerial mySerial(10, 11); // RX, TX
String rec_data="off"; // closed

void setup() {
pinMode(9, OUTPUT);
Serial.begin(9600);
mySerial.begin(9600); // BlueTooth Data baud,set the data rate for the SoftwareSerial port
}

void loop() { // run over and over
if (mySerial.available()) {

rec_data=mySerial.readString();

if(rec_data=="on"){digitalWrite(9, HIGH);} // RELAY out ---> pin 9---> on
if(rec_data=="off"){digitalWrite(9, LOW);} // RELAY out ---> pin 9 --- off

Serial.println(rec_data);
delay(100);
}

}