Day by day, as the technology is rapidly progressing that affect the human daily lives more flexible, especially in controlling home appliances. Electrical installations are the heart of every building, thus intelligent building control absolutely ensures the safety and efficient control and finally saves the power consumption and manpower. Home automation system does the operations such as lighting control & regulation, regulating heating, equipment’s ventilation and air con equipment, load, and energy management, audio or video systems, security and monitoring, human machine interfaces and other control tasks.
RF Based Home Automation System
To develop a home automation system with an RF controlled remote, houses are also getting smarter. As technology is advancing so houses are also getting smarter.Modern houses are gradually shifting from conventional switches to a centralized control system, involving radio frequency controlled switches.
At present, conventional wall switches located in different parts of the house make it difficult for the operator to go near them to operate.In order to complete this, an RF remote is interfaced to the microcontroller on the TX side which sends commands to the receiver where different loads are connected. By operating the particular remote switch on the TX, the loads can be switched ON/OFF remotely through wireless technology.
This circuit uses an RF module to make a wireless remote, which could be used to drive an o/p from a distance place. As the name suggests, RF module uses radio frequency to send signals, which are transmitted at a specific frequency & a baud rate.
Hardware and Software Requirements
The hardware and software requirements of RF-based home automation system include Series Microcontroller, Transformer, Opto-isolator, TRIAC, Voltage Regulator, Crystal Diodes, Resistors, Capacitors, Lamps, RF modules, Push Buttons, Keil compiler, and Languages: Embedded C or Assembly.
RF Transmitter and Receiver
- Normally, RF modules are divided into three groups, RF TX module, RF receiver module, and RF transceiver module.
- 433MHz, ASK transmitter and receiver are used for the remote control.
Features of RF
The main features of RF transmitter include the following
- Range in standard conditions is 100 meters
- RX frequency-433MHz
- Typical sensitivity-105Dbm
- Supply current of RX-3.5 mA
- IF frequency of RX-1MHz
- Low power consumption
- Easy for Application
- Operating voltage of RX-5V
- Frequency range of TX-433.92MHz
- Supply voltage of TX- 3V to 6VO/p of TX- 4 to 12 dBm
- Encoder HT12E IC gets parallel data in the form of address and control bits
- The control signals from remote switches along with 8-bits constitute a set of 12 parallel signals
- The encoder converts the parallel inputs into a serial set of signals.
- These signals are serially transmitted through RF to the response point.
- Transmission is permitted by providing ground to pin-14 which is active low.
- In the receiver circuit, we use an RF module to get the information and decoded by the decoder.
- Decoder delivers the data into 4-bit and we use the further control circuit to switch ON/OFF.
- The decoder is used after the RF receiver to decode the serial format and regain the original signals as o/ps.
- This o/ ps can be observed on equivalent LEDs.
- Opto-coupler MOC3061 or MOC3063 a LED, SCR sort combination.
- It is a 6-pin IC.
- Additionally, while using this IC with a microcontroller and also LED can be connected in series with IC LED to specify when the high is given from microcontroller so that we can know that flow of current is in internal LED of the opto-IC.
- When the logic high is given, then the current flow through LED from pin 1 to 2
- So in this process, LED falls on SCR to cause pins 4 and 6 to close only at the zero cross of the supply voltage.
BC547 NPN Transistor
- The transistor (BC547) is an NPN epitaxial silicon transistor
- This transistor is used in general purpose switching & amplification BC847 or BC547 series 45V, 100mA NPN general purpose transistors.
- The ratio of two currents ‘Ic’ and ‘Ib’ is called the C current gain of the device and is given the symbol of hfe or beta.
- The current gain from the Emitter (E) to the collector terminal is called alpha.
The main goal of this project is to design a home automation system with an RF controlled remote. As day by day technology is advancing and houses are getting smarter. These houses are progressively changing from conventional switches to the integrated control system, including RF controlled switches.
Presently, conventional wall switches located in various parts of the house make it difficult for the user to go nearby them to work. Even more, it becomes more difficult for the elderly or physically handicapped people to do so. The proposed system offers a simple solution with RF technology.
In order to get this, an RF remote is connected to the microcontroller on the TX side which sends ON/OFF signals to the RX where different loads are connected. By operating the particular remote switch on the TX, the loads can be switched ON/OFF remotely through wireless technology.
The microcontroller used here is 8051 family, the different loads are connected to the microcontroller using TRIACs and Opto-isolators.
Applications of RF-Based Home Automation System
The applications of RF-based home automation system include the following
- Burglar alarm, smoke alarm, fire alarm, car alarm, security system, etc.
- Car door and garage door controllers
- Cordless telephone
- Other remote control systems
- Wireless security systems
- Car alarm systems
- Remote controls
- Sensor reporting
Thus, this is all about RF based home automation system. We hope that you have got a better understanding of this concept. Furthermore, any queries regarding this concept or to implement any home automation projects, please give your valuable suggestions by commenting in the comment section below. Here is a question for you, What are the applications of home automation system?