Introduction: Voice/text Controlled Home Automation Using Arduino and Android App With Switch Provision

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Hello everyone!

The main objective of this project is to develop a home automation system using an Arduino Uno with Bluetooth being controlled by an Android smartphone. As technology is advancing so houses are also getting smarter. Modern houses are gradually shifting from conventional switches to the centralized control system, involving remote controlled switches. Presently, conventional wall switches located in different parts of the house makes it difficult for the user to go near them to operate. Even more, it becomes more difficult for the elderly or physically handicapped people to do so. Home automation system provides a most modern solution with smartphones. Moreover, home automation systems in today’s market cost is too expensive so also wanted to make a low budget home automation system.

In order to achieve this, a Bluetooth module is interfaced to the Arduino UNO at the receiver end while on the transmitter end, a android application on the cell phone sends ON/OFF commands to the receiver where loads are connected. By either speaking or texting on the android App the loads can be turned ON/OFF remotely through this technology.

Here, I have added an extra feature to it, that of a switch.If you turn ON the appliance from your app, you can turn it OFF by toggling the switch. Hence, the switch acts as a switch directly placed in your switch-board.This feature has been added very thoughtfully because if we think practically, we wouldn't always use the app to turn ON/OFF the appliance. If you are nearby to the switch board, or you are not in possession of your phone, you can just toggle the switch to turn ON/OFF the appliance.Since we use a mechanical switch, the Arduino does not know whether presently, the appliance is ON or OFF. This is why a feedback has been added. A 5V adapter is connected in parallel to the load whose output is given between analog input A5 and GND of the Arduino.

Transistor - BC547

The control signal from Arduino pin 13 is connected to base via 1K resistor and GND is connected to emitter. This transistor - resistor circuit is the Relay Driver Circuit and it controls the relay switch position.

For the 12V to 5V adapter, you may use an IC7805 circuit which you can easily find on Google Images.

Relay - 250V 10A SPDT

Note: Use common ground for the circuit, otherwise the relay and other components behave erratically.Be careful with the relay connections. Lookout for the pin configuration of SPDT relay. Its coil is connected to the driver circuit and the 'C', 'NC', 'NO' are connected to LIVE line as shown in circuit diagram.Be very careful as you are using the mains line. If you are not confident enough, take someone's help who knows about these things. As a precautionary measure, you may connect a lower DC voltage from a regulated power supply to ensure everything works fine, and then connect the LIVE wire.

If you have any queries, comment below and I will definitely get back to you.

You can see the demonstration video in the above Video link

Thank You!

Sources - Electronics For You, Google, Youtube, etc.

Made by - Rahul Fatnani, Nikhil Shah, Manasi Bhavsar, Nipun Bhirud.

Step 1: Hardware Requirements

1.Arduino UNO.

2.HC-05 Bluetooth Module.

3. Relay Module.

4.Transistor BC547


6.Dc Power Supply Module

7.Electrical Appliance (i have used Led bulb)

Step 2: Making Up of Circuit

Wire Up The Circuit According To the circuit diagram shown

For Bluetooth Module:-

1)VCC => 3.3V

2)GND => GND

3)Rx => Tx

4)Tx => Rx

Step 3: Software Part

Make arduino sketch depending on your configuration and upload it using arduino IDE.

If you don't have an IDE, download from

Step 4: Build Your Own Customised App

I have used MIT app inventor to design my own simple application to control device through my Smartphone using text and voice.

For learning how to make app on Mit App inventor 2

Step 5: Ready to Go

Open up your Smartphone

-Start your device bluetooth.

-Run the app designed for Home Automation.

-Pair up with the HC-05 BT module.

-Control desired device.

I hope that you found this instructable useful.

The demonstrative video is also attached here.

Automate your room now !!!

If you liked the project or are encouraged to make something related to Electronics please do vote for below contest.


Arduino Contest 2020

Participated in the
Arduino Contest 2020