RF Based Home Automation System

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RF based Home Automation System
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RF based Home Automation System
What is Home Automation

• As the technologies are rapidly advancing that
  affects the human daily lives more flexible,
  particularly in controlling home appliances.
• Electrical installations are the heart of every
  building, therefore intelligent building control
  absolutely ensures the safety and efficient
  control and eventually saves the electric power
  consumption and human energy.
• Home automation system does the operations like
  lighting control and regulation, regulating HVAC
  (Heating, Ventilation and Air Conditioning)
  equipments, energy and load management, security
  and monitoring, audio/ video systems, HMIs and
  other control tasks.

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RF based Home Automation System
Introduction to RF based Home Automation System

• To develop a home automation system with a 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 centralized control
  system, involving RF controlled switches.

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RF based Home Automation System

• Functional Description
• Presently, conventional wall switches located in
  different parts of the house makes it difficult
  for the user to go near them to operate.
• In order to achieve this, a RF remote is
  interfaced to the microcontroller on transmitter
  side which sends ON/OFF commands to the receiver
  where loads are connected.
• By operating the specified remote switch on the
  transmitter, the loads can be turned ON/OFF
  remotely through wireless technology.
• This circuit utilizes the RF module (Tx/Rx) for
  making a wireless remote, which could be used to
  drive an output from a distant place.
• RF module, as the name suggests, uses radio
  frequency to send signals . These signals are
  transmitted at a particular frequency and a baud
  rate.

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RF based Home Automation System
Block Diagram For Transmitter
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RF based Home Automation System
Block Diagram For Receiver
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RF based Home Automation System

• Hardware Requirements
• 8051 series Microcontroller
• Transformer
• Opto-isolator
• TRIAC
• Voltage Regulator
• Crystal
• Diodes
• Resistors
• Capacitors
• Lamps
• RF modules
• Push Buttons.

• Software Requirements
• Keil compiler.

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RF based Home Automation System

• RF Transmitter and Receiver
• RF modules are normally divided into three
  groups, RF transmitter module, RF receiver module
  and RF transceiver module .
• 433MHz ASK transmitter and receiver is used for
  the remote control.

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RF based Home Automation System

• Features of RF
• Range in open space(Standard Conditions) 100
  Meters
• RX Receiver Frequency 433 MHz
• RX Typical Sensitivity 105 Dbm
• RX Supply Current 3.5 mA
• RX IF Frequency 1MHz
• Low Power Consumption
• Easy For Application
• RX Operating Voltage 5V
• TX Frequency Range 433.92 MHz
• TX Supply Voltage 3V 6V
• TX Out Put Power 4 12 Dbm

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RF based Home Automation System

• Encoder
• Encoder IC (HT12E) receives parallel data in the
  form of address bits and control bits.
• The control signals from remote switches along
  with8 address bits constitute a set of 12
  parallel signals.
• The encoder converts the parallel inputs (from
  the remote switches) into serial set of signals.
• These signals are serially transferred through RF
  to the reception point.
• Transmission is enabled by providing ground
  topin14 which is active low.

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RF based Home Automation System

• Decoder
• In the receiver circuit we use RF module to get
  the data and decoded by the decoder.
• Decoder deliver the data into 4 bit and we use
  further control circuit to switch on/off.
• The decoder is used after the RF receiver to
  decode the serial format and retrieve the
  original signals as out puts. These outputs can
  be observed on corresponding LEDs.

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RF based Home Automation System

• Opto-isolator
• Opto-coupler MOC3061/63 an LED SCR type
  combination.
• Opto coupler is a 6 pin IC.
• Additionally while using this IC with
  microcontroller and one LED can be connected in
  series with IC LED to indicate when high is given
  from micro controller such that we can know that
  current is flowing in internal LED of the
  opto-IC.
• When logic high is given current flows through
  LED from pin 1 to 2 .
• So in this process LED light falls on SCR causing
  6 4 to close only at the zero cross of the
  supply voltage.

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RF based Home Automation System

• BC547 (NPN Transistor)
• The BC547 transistor is an NPN Epitaxial Silicon
  Transistor.
• It is used in general-purpose switching and
  amplification BC847/BC547 series 45 V, 100 mA NPN
  general-purpose transistors.
• The ratio of two currents (Ic/Ib) is called the
  DC Current Gain of the device and is given the
  symbol of hfe or nowadays Beta, (ß).
• The current gain from the emitter to the
  collector terminal, Ic/Ie, is called Alpha, (a),
  and is a function of the transistor itself

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RF based Home Automation System
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RF based Home Automation System

• Applications
• Burglar Alarm, Smoke Alarm, Fire Alarm , Car
  Alarm, Security System.
• Garage Door and Car Door Controllers.
• Cordless telephone.
• Other Remote Control System.
• Wireless security systems.
• Car Alarm systems.
• Remote controls.
• Sensor reporting.

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