In the past few years there are so many inventions in the field of consumer electronics such as cellular phone, air conditions, home security devices and home theaters. All these appliances can be easily controlled by a single controller, using personal area network in a home environment. Busy environment and personal limitation the market is going towards the home automation and networking and Bluetooth is an ideal solution for this purpose. In buildings, temperature and other electronic devices can be easily controlled by home automation but high degree of computer work is involved. This report demonstrates a simple home automation system which consists of remote mobile, host controller, and several home appliances. The client module can communicate with host controller through a wireless device such as Bluetooth. The overview of this report is shown in Fig 1
Home Automation system using Bluetooth
Automation is also involved in building management system in which lights, temperature, security devices and other appliances are controlled through a high degree of computer involvement. In this report, all the devices which are used in building management system are control by a single controller using a wireless network .Client module and host controller are used to communicate with each other through a wireless device such as Bluetooth enabled the mobile phone. In this report, an android based smart phone is used. Home automation is not a new thing but the advanced automation system in nowadays require a big and expensive infrastructure. In this report, we have proposed a low cost, flexible secure automation system that can easily control TV, tube lights and fans from android based mobile phone using Bluetooth. Here HC-05 Bluetooth module and 8-bit microcontroller atmel89s52 is used for switching. This board has 32 digital input and outputs ports.
BLOCK DIAGRAM of Bluetooth based Home Automation
In this block diagram microcontroller is programmed in C language and used to turn on and off the appliances, which are connected through relays, when we send the commands through Bluetooth from a mobile phone. A feedback circuit is also designed and implement to check the current status of the device after it receives the command from mobile phone. Once the command has sent to turn on the device, then the feedback circuit first check the current status then send the command to turn on and the circuitry led indicates the turn on device, otherwise the device indicate the malfunctioning that the command was not executed successfully. The communication is done one by one at one time in both direction between the android mobile phone and Bluetooth module. This communication is called half duplex. The feedback circuit is run at 220 V.
Component of Android phone based home automation system
In this circuit diagram AT89c52 microcontroller is used which consist of CPU, RAM, ROM, timers and input, outputs ports .It is just like a computer only difference is the memory and also no need to use any microprocessor to make any function. The AT89c52 is low power, high performance 8 bit microcontroller with 8k bytes programmable flash memory. The device is manufactured using Atmel high-density nonvolatile memory technology and is compatible with the industry standard 80c51 instruction set pin output. Three relays RL1, RL2 and RL3 are connected to the microcontroller through the print circuit board for controlling the home appliances. you can check relay interfacing with microcontroller to know more about it. Relay driver circuit ULN2003 is used to drive relays.
BLUETOOTH MODULE (HC-05)
For the communication between mobile phone and microcontroller Bluetooth module is used, because the microcontroller can’t do all this work itself. Hc-05 module is used for this purposes, which is low power 1.8 v operation, PIO control with integrated antenna, edge connector and is easy to use with Bluetooth SPP (serial port protocol).This is designed for transparent wireless serial connection setup. Serial port Bluetooth module have a Bluetooth 2.0+EDR (enhanced data rate), 3Mbps modulation with complete 2.4GHZ radio transceiver and baseband. Using Bluetooth profile and android platform architecture different type of Bluetooth applications can be developed.
SWITCHES: Switches are used to make and break the electrical circuit. There are so many types of switches, some are mechanically and some are electrically operated such as SPDT, SPST, DPST, DPDT etc. you can check push button interfacing article to use it in your microcontroller based project.
RELAYS: Relay is basically an electromagnetic switch which can be turn on and off by an applying the voltage across its contacts. In this project, we used a 6 volts relay.
In this project 5 volt 700 mA Samsung charger is used for giving the power to the circuit and made of switch mode power supply.
PROTEUS: For the designing of this project with hardware component proteus software is used, which is fast, accurate, flexible and high performance simulator for MIMD multiprocessor. This can be reproduced the results from real multiprocessor and configured to simulate a wide range of architecture. you can watch Proteus video tutorials here.
KEIL:For converting the C language in HEX file Keil software is used which can easily burn in microcontroller.
ANDROID APP: It is mobile operating software developed by google based on Linux kernel and is used in touchscreen mobile devices such as smartphones and tablets.it have a so much human interference and in this project we have used it for home automation to control the home appliances.
- It is a robust and easy to use system.
- There is no need for extra training of that person who is using it.
- All the control would be in your hands by using this home automation system.
- This project can provide the facility of monitoring all the appliances with in the communication range through Bluetooth.
- By using this system the users can check the status of the appliances at whatever time of the day
- Manual control is also given in this project so the unskilled person can easily change the status.
- Bluetooth is used in this home automation system, which have a rage 10 to 20 meters so the control cannot be achieved from outside this range.
- Application is connected after disconnect of the Bluetooth.
- when the new users want to connect the first download application software then the code and configuration must be done
Code of Android-based home automation system
I recommend you to write your own code for android based home automation system using any microcontroller you like to use. you can use GSM, ZIGBEE and any other wireless communication in your project. I recommend you to use microcontroller which has more built-in features so that you don’t have to use more external circuitry. I recommend you to write your own code. But if you want to purchase code, contact me through my email: firstname.lastname@example.org.