pc based elctrical appiance control

Shri Vaishnav Institute of Technology & Science









PC Based Wirelesse Controll Appliances

Major project
Submitted towards partial fulfillment of the
Degree of Bachelor of Engineering
Year 2013-14

Department of Electrical and Electronics Engineering




Guided by Submitted by
Miss Toshi Mandloi Akash Patidar (0802EX081004)

Dharmendra (0802EX081017)

Prsson paul (0802EX091033)
Satish Rathore (0802EX091046)












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Shri Vaishnav Institute of Technology & Science, Indore

Department of Electrical & Electronics Engineering

CERTIFICATE

This is to certify that Akash Patidar,darmendra parmar,Prasson Paul and
Satish Rathore have successfully and satisfactorily completed the project
work titled “PC based wireless control appliances” towards the partial
fulfillment of degree of Bachelor of Engineering in Electrical and
Electronics awarded by Rajiv Gandhi Technical University Bhopal
for the academic year 2013-2014.




Project Guide Head of Department




Internal Examiner External Examiner













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Shri Vaishnav Institute of Technology & Science, Indore

Department of Electrical and Electronics Engineering

ACKNOWLEDGEMENT

We Acknowledge, with celerity and a deep sense of gratitude, the invaluable guidance
given to us by Miss Toshi Mandloi (project guide) he suggestions and discussion were
enlightened and a constant sourceof inspirations for us during our project work. We are
indebted to her for helping us in acquiring knowledge of the practical applications of the
concepts studied during the semester and answering to all our queries related to our
project.

We express our heartfelt thanks to Mr. Anil K. Jain , Head of Department of Electrical
and Electronics , for providing with an opportunity to do this project and giving
invaluable encouragement in our endeavors .





















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ABBREVIATION & NOTATIONS


HT12D Decoder IC
HT12E Encoder IC
CMOS Complementary Metal Oxide Semiconductor
EEPROM
Electrically Erasable Programmable Read Only
Memory
IC Integrated Circuit
TE Transmitter Enable Pin
LCD Liquid Crystal Display
MCU Microcontroller Unit
PC Personal Computer
PCB Printed Circuit Board
RAM Random Access Memory
RF Radio Frequency
ROM Read Only Memory
LED Light Emitting Diode
S1&S2 Switches
Am Amplitude Modulator
IR Infrared
GND Ground

Table 1 Abbrevation and Notation






























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CONTENTS

Cover page I
Acknowledgement II
Certificate III
Abbreviations & Notations IV


Chapter N Subject Page No.
1. Design Objective...........................................,..........................06
2. Physical & Technical Specifications......................,,…..07-08
3. System Description.................................................,,,.......09-16
3.1 Introduction................................................,........................09
3.2 System Block Diagram & Description..........,,,…………10-13
3.3 PCB Construction.............................,,,,,.............................14
3.4 List of Components......................................,...,…………..15
3.5 Receiver&Transmitter Description..............,....................16
3.6 Flow chart of HT12D&HT12E……………,,…………..17&18
3.7 IC DM74LS138………………………………,,…………19


Application

Result

Future Suggestions & Enhancement

References

Annexure




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DESIGN OBJECTIVE


 To design and implement PCB we have used eagle software. In this software we have first of all
design PCB layout on a glossy paper than layout applied on the PCB .

 After the design of layout .


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PHYSICAL AND TECHNICAL SPECIFICATIONS


1] Physical Specifications:

1.a] Box Dimensions
Length: 25cm
Breadth: 12cm
Height: 06cm

1.b] PCB Dimensions
Transmitter Section: 10x 07cm
Receiving Section: 05 x 8 cm


1.c] Transformer
Length: 4 cm
Breadth: 2cm
Height: 4cm

1.d] PCB Material
Glass Epoxy Plate
Cu-Clad Plate




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2] Technical specifications:

2.1 Power Supply Requirements
2.1.1 Decoder IC HT12D 2.4V to 12V
2.1.2 Encoder IC HT12E 2.4Vto 12V
2.1.3 5V-12V single-supply operation

2.2 Power Source
current drain for VCC of 5V and 12V



2.3 Operating Temperatures
2.3.1 Demultiplexer DM74LS138…………… 0C to 70
2.3.2 Storage Temperature ............................50C to 125C

2.3.3 Operating Temperature...........................20C to 75C


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SYSTEM DESCRIPTION

INTRODUCTION
The parallel port of the PC is a powerful platform of implementing projects dealing with the control
of the real world peripherals. It can be used to control home and other electronics appliances. The
computer program through the interface circuit controls the relays which in turn switch the appliance
on or off. Here we wirelessly control appliances from remote place by using the RF module. For this
“PC BASED WIRELESS CONTROL” system, Hardware as well as Software is required. The
parallel port of the PC used to control the appliances at the transmitter side. The RF interface is used
to control appliances within 150 meters range. The PC signals are transmitted from RF transmitter
&received by RF receiver
 Remote control.
 For remote control, we have used the Holtek encoder-decoder pair of HT12E and
HT12D. Both of the seare 18-pin DIP ICs.
HT12E and HT12D are CMOS ICs with operating voltage range of 2.4V to 12V.
Encoder HT12Ehaseight addresses and another four address/data lines. The data set
on these twelve
 lines (address and address/data lines) is serially transmitted when the transmitted
able pin (TE) is taken low. The data output appears serially on D
OUT
pin.
The data is transmitted four times in succession. It consists of differing lengths of
positive pulses for ‘1’ and ‘0,’ the pulse-width for ‘0’ being twice the pulse width
for ‘1.’ The frequency of these pulses may lie between 1.5 and 7 kHz depending on
the resistor value between OSC1 and OSC2 pins.
The internal oscillator frequency of decoder HT12D is 50 times the oscillator
frequency of encoder HT12E. The values of the timing resistors connected between
OSC1 and OSC2 pins of HT12E and HT12D, for a given voltage supply, can be
found out from the graphs given in the data sheets of the respective chips. Here
we have chosen the resistor values for approximately 3kHz frequency of the
encoder (HT12E) and 150 kHz of the decoder (HT12D) at V
dd
of 5V.
The HT12D receives data from the HT12E on its D
IN
pin, serially. If the address
part of the received data matches the levels on A0 through A7 pins four times in
succession, the valid transmission (VT) pin goes high. The data on pins AD8
through AD11 of the HT12E appears on pins D8 through D11 of the HT12D. Thus
the device acts as a receiver of the 4-bit data (16 possible codes) with 8-bit
addressing (256 possible channels).
Once the frequency of the pair is aligned, then on ground of any data pin on the
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encoder, LED1 on the decoder should light up. You can also check the data
transfer on pins AD8through AD11, which is available on pins D8 through D11 of
the decoder once TE pin is momentarily taken low by making it ground
11


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PCB LAYOUT OF TRANSMITTING SECTION
The RF transmitter TX-433 is AM/ ASK type and its circuit diagram(HT12E)

.

Signals from the Pc‟s parallel port are interfaced to the RF transmitter through the RF encoder. The
encoder (HT12E) continuously reads the status of the opt coupler (MCT2E), passes the data to the
RF transmitter and the transmitter transmits the data. The RF receiver receives this data and gives it
to the RF decoder (HT12D). The decoder converts the single-bit data into four-bit data and presents
it to the decoder (74LS138). The output of the decoder controls the appliances with the help of flip-
flops (CD4013) and transistors. Now, relays perform the corresponding action i.e. switch the
appliances „on‟ or „off.‟



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PCB LAYOUT OF RECEIVING SECTION
The RF receiver receives this data and gives it to the RF decoder (HT12D).




The HT12D receives data from the HT12E on its D
IN
pin, serially. If the address part of the received
data matches the levels on A0 through A7 pins four times in succession, the valid transmission (VT)
pin goes high. The data on pins AD8 through AD11 of the HT12E appears on pins D8 through D11
of the HT12D. Thus the device acts as a receiver of the 4-bit data (16 possible codes) with 8-bit
addressing (256 possible channels).




.
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PCB Construction


Fig.5:An actual-size, single-side
PCB forthe transmitter circuit



Fig.7: Actual-size, single-side PCB for
the receiver and logic control section
(on the left side of dotted line)


Fig.9: Actual-size, single-side PCB
for the relay driver section(on the right side of dotted line)

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List of Components




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Transmitter.
Fig.3 shows the transmitter circuit for PC-based wireless appliance control. The receiver address
to be transmitted can be set with the help of an 8-way DIP switch (DIP-SW1). If any switch is
open the pin connected to that switch is at logic 1, and if it is closed the respective pin is at logic
0. The data pins are pulled high via resistors R2 through R5.

When pin 2 of the parallel port goes high, the internal LED of the optocoupler(MCT2E) glows to
drive the internal phototransistor into saturation and its pin 5 goes low.

Pin 10 (AD8) of HT12E goes low through pin 5 of MCT2E and a „0‟ is sent at that data position,
while other data pins represent the logic-1 state. The logic circuitry at the receiver-decoder end
decodes the data appropriately for controlling the switch of an appliance.


Receiver-cum-decoder.
Fig.4 shows the receiver circuit for PC-based wireless appliance control. Assuming that an
identical address is selected on the encoder and decoder, when anyone of data pins D0 through D3
of the PC‟s parallel port on the transmitter is high, the corresponding data pin of the demodulator
goes low at the decoder (HT12D). The data outputs (D8 through D11) of HT12D are connected to
inverters N1 through N4. The output of inverters N1, N2 and N3 are connected to address inputs
A, B and C of decoder 74LS138, respectively. The outputs of inverters N4 and N5 enable the
decoder to drive the flip-flop (CD4013).

IC CD4013 is configured as a toggle flip-flop. The output of the flipflop (IC9(A)) drives transistor
T2 into saturation and relay RL1 energises. D7 through D14 are used as free-wheeling diodes. The
relay contacts are used for appliances.

When any data is received, the valid transmission pin (VT) goes high to drive the transistor into
saturation and LED1 lights up.
RF transmitter and receiver

The RF transmitter and receiver modules from Alpus India, Mumbai, have been employed for RF
remote control.

The RF transmitter TX-433 is AM/ ASK type. It features:

1. 5V-12V single-supply operation
2. On-off keying (OOK)/amplitude shift keying (ASK) data format
3. Up to 9.6kbps data rate
4. +9dBm output power (a range of about 200 metres)
5. SAW-based architecture and For the antenna, a 45cm wire is adequate
The output power and current drain for VCC of 5V and 12V, respectively.

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Flow chart of IC HT12D


The 212 decoders are a series of CMOS LSIs for remote control system applications. They are
paired withHoltek s212 series of encoders (refer to theencoder/decodercross reference table).
For proper operation, apair of encoder/decoder with the same number of address Resand data
format shouldbechosen.The decoders receive serial addresses and data from programmed 212
series of encoders that are transmittedby a carrier using an RFor an IR transmission
medium.They compare the serial input data three times continuouslywith their local addresses.
If no error or unmatched codes are found, the input data codes aredecoded and then transferred
to the output pins. The VTpin also goes high to indicate a valid transmission.The 212 series of
decoders are capable of decoding information that consist of N bits of address and 12_Nbits of
data. Of this series, the HT12D is arranged to provide8 address bits and 4 data bits, and HT12F
is used todecode 12 bits of address information.



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Flow Chart of IC HT12E

1~





~
`1







The 212 encoders are a series of CMOS LSIs forremote control system applications. They
arecapable of encoding information which consists of N address bits and 12_N data bits. Each
address/data input can be set to one of the twologic states. The programmed addresses/dataare
transmitted together with the header bitsvia an RF or an infrared transmission mediumupon receipt
of a trigger signal. The capabilityto select a TE trigger on the HT12E or a DATAtrigger on the
HT12A further enhances the applicationflexibility of the 212 series of encoders.The HT12A
additionally provides a 38kHz carrierfor infrared systems


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IC DM74LS138 General Description
These Schottky-clamped circuits are designed to be usedin high-performance memory-decoding or
data-routingapplications, requiring very short propagation delay times.In high-performance memory
systems these decoders canbe used to minimize the effects of system decoding. Whenused with high-
speed memories, the delay times of thesedecoders are usually less than the typical access time ofthe
memory. This means that the effective system delayintroduced by the decoder is negligible.The
DM74LS138 decodes one-of-eight lines, based uponthe conditions at the three binary select inputs
and thethree enable inputs. Two active-low and one active-highenable inputs reduce the need for
external gates or inverterswhen expanding. A 24-line decoder can be implementedwith no external
inverters, and a 32-line decoderrequires only one inverter. An enable input can be used asa data input
for demultiplexingapplications.The DM74LS139 comprises two separate two-line-to-fourlinedecoders
in a single package. The active-low enableinput can be used as a data line in demultiplexing
applications.All of these decoders/ demultiplexers feature fully bufferedinputs, presenting only one
normalized load to its drivingcircuit. All inputs are clamped with high-performanceSchottky diodes to
suppress line-ringing and simplify systemdesign.
























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Connection Diagram






Software

The source program for PC-based wireless appliance control is written in Visual Basic. To use the
software on Win XP platform, the input32.dll file should reside in the same folder as the .exe file of
the program. The main screen for PC-based wireless appliance control is shown in Fig.11.


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Fig.11: Main screen on PC

































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Application
Now in our day to day life the PC plays such a vital role that without which the life would have
been difficult in every aspect. For example in banks, firms, industries, etc PCs are
needed to handle more than one operations. More and more PC based product sare being made
and used in our day to day life. One of the project which will control the appliances
through PC is done here to make our life simpler and we can control the appliances
sitting at single location through PC. This project can be used where the control of
different appliances is to be done with PC i.e. in some industries and firms in order to µon
and off the different mechanisms and machines. This can also be used in some offices where
different appliances like fans, tube lights, etc are needed to switch off and µon according
to the need. Also this can also be used at home as comfort of life are increasing day
to day and every electronic appliances are being remote operated so this can be used
so that different appliance can be controlled with the help of PC .There is no need to go at
different places to switch the appliances on and off, instead many of the appliances
which are needed to on and off at regular interval can be interfaced with this circuit
and we can control all the appliances from a single locatio

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RESULT



We have successfully developed a front panel in visual basic in software part and had
written a code in order to interface our transmitter circuit with PC. Then we interfaced
transmitter, receiver and relay driver circuit. Also we had connected the power supply
and given required voltages and have arranged the things in a manner they should be and
had run the project successfully. the arrangements we have done in order to run the project and
here we had only connected one device i.e we have only controlled a single device
LED. In the similar manner we can connect other devices so that it can be controlled with the help
of PC

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SUGGESTIONS & FUTURE ENHANCEMENTS

a) The aim of home automation is to control home devices from a
central control point. In this paper, we present the design and
implementation of a low cost but yet flexible and secure Internet
based home automation system. The communication between the
devices is wireless. The protocol between the units in the design
is enhanced to be suitable for most of the appliances. The system
is designed to be low cost and flexible with the increasing variety
of devices to be controlled.

b) PC-Communication could be added with an aim to allow dumping of data
from device to compute where it can be stored with more fidelity and user
friendly interface.

c) Signals from the PC parallel port are interfaced to the RF transmitter through
the RF encoder. The encoder continuously reads the status of the opto-coupler
passes the data to the RF transmitter & the transmitter transmits the data.
The RF receiver receives this data & gives it to the RF decoder. The
decoders converts the signals/bit data into 4 bit data & present it to the
multiplexer decoder.The output of decoder controls the appliances with the
help of flip-flop & transistors now relay performs the corresponding action so
that switch the appliances on or off .
















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REFERENCES



ANSHUMAN BEZBORAH AND ARUNAV KUMAR SINHA


1. Microcontroller Projects in C for 8051”

2. www.efy.com

3. www.electronics4you.com

4. www.efy.com/mag2009/intr

















Pc based wireless home appliances control