bitirme son

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T.C

DOKUZ EYLUL UNIVERSITYENGINEERING FACULTYELECTRICAL & ELECTRONICSENGINEERING DEPARTMENT

IR REMOTE CONTROLLER for HOMEAPPLIANCES via WI-FI

(HARDWARE PART)

FINAL YEAR PROJECT

VOLKAN DENZ

Adviser

Asst. Prof. Dr. Olcay Akay

JUNE 2009ZMR


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PROJECT EXAMINATION RESULT FORM

We certify that we have read this project and that in our opinion it is fully

adequate, in scope and in quality, as a senior project.

.Asst. Prof. Dr. Olcay Akay

(Adviser)

.

Assist. Prof. Dr. Ahmet zkurt(Committee Member)

.Assist. Prof. Dr. zge ahin

(Committee Member)

.

Prof. Dr. Mustafa GNDZALP

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(Chairman)

ACKNOWLEDGEMENTS

I would like to thank my advisor, Asst. Prof. Dr. Olcay Akay for his help in

guidance and supervision during this project.

I would like to specifically thank Asst. Prof. Dr. Nalan zkurt for her valuable advice and help during the project.

I also would like to thank GRUNDIG A.. for their guidance and advice.

I would like to thank my friend Ahmet Tekin for being with me during

realization of this final year project.

I also would like to thank Mert zuysal, Nejdet Tayyar Irga, Arif Ataman

and Osman Tayfun Bikin for helps in critical situations.

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ABSTRACT

The aim of this project is to control the VCD player and heater by using a PC

interface. PC sends the data to microcontroller via Wi-Fi and the microcontroller

controlls the VCD player with infrared (IR) communication.

While all IR remote controls share the basic concept of communicating from

the remote control to the home entertainment device via IR signal, there is no

universal standard for the encoding method. All IR remote control systems use IR

light-emitting diodes (LEDs) to send out an IR signal in response to button pushes.

The pattern of pulses indicates the particular button pushed. To allow control of

multiple appliances such as a TV, DVD Player, air conditioner and cable box without

interference, systems generally have a preamble and address to synchronize the

receiver and identify the source (and destination) of the infrared signal. Some of the

earliest remote controls (and to this day a few cable box remote controls) use a

simple system in which the IR LED is simply turned on and off. However, to avoid

interference by other light sources, especially flourescent bulbs, and keep the signal

from being swamped out by ambient light, most systems digitally modulate a carrier

frequency of between 36 kHz and 40 kHz. A bandpass filter in the receiving unit

eliminates all but the desired frequency.

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ZET

Bu projede vcd alar ve stclarn bilgisayardan kontrol amalanmtr.

Bilgisayardan wireless module araclyla yollanan bilgiler mikroilemciye gider ve

mikroilemci de vcd alar ve stcy infared ile kontrol eder.

Infrared ile alan dier ev aletleri de ayn iletiim konseptine sahiptirler ve

bu ekilde kontrol edilebilirler. Infrared iletiim IR ledler kullanlmaktadr, tua her

basta bu ledler elimizdeki bilgiyi kontrol edeceimiz alete iletir ve bu ilemde

herhangi bir uluslar aras standart yoktur, her firmann ayr kodlama ve kod zme

teknii vardr. TV, klima gibi ev aletleri de bu ilemle altrlabilir. Infrared ilk

kullanlmaya balandnda aletler sadece a kapa yapabiliyorlard,daha sonra btn

tular kullanlmaya baland ve evimizdeki ou alet infrared iletiime geti.

IR ledler gne ndan etkilenebilmektedir ve elimizdeki bilginin zerine

grlt biner, bu yzden bu ledleri gne ndan uzak tutmak gerekir.

Modulasyon ilemi kullanacamz aletlere gre 36 kHz ile 40 kHz arasnda

deimektedir ve her firma kendine uygun bir frekans seer.Cihazmzn alc nitesi

blm gnderdiimiz bilgiyi anlayabilme kabiliyetine sahiptir, bir band geirici

filtre ile gelen bilgi okunabilir. Her firma kullanm kolayl salayacak bir kodlamave kod zme ilemi uygular. Genel olarak RC5 ve NEC kodlama trleri

kullanlmaktadr.

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CONTENTS

CONTENTS.............................................................................................6

LIST OF FIGURES........8

Chapter 1. INTRODUCTION.....................................................9

Chapter 2. THEORETICAL FOUNDATIONS INFRARED (IR)RADIATION ......10

2.1.Infrared Lights..................................................10

2.2.IR Remote Controllers......10

Chapter 3. HARDWARE DESIGN...13

3.1.Proteus Design...13

3.2.Receiver......143.3.PIC16F877.....15

3.3.1 Features...15

3.4.Transmitter and Timer ....17

3.5.Linear Regulator (7805)...19

Chapter 4. SOFTWARE DESIGN.......20

4.1 Software Design of VCD Player ..21

4.1.1 Features.....21

4.2. Software Design of Heater...22

4.2.1 Features.....22

4.3 PC INTERFACE...24

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Chapter 5. WIRELESS MODULE25

5.1.Features..25

5.2.General Description .25

5.3.Hardware ..26

5.4.Performance Specifications..27

5.5.Configuration.27Chapter 6. RESULTS and CONCLUSION................................29

REFERENCES .....................................................................................31

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LIST OF FIGURES

Figure 2.1: Transmitting data signal by driving an IR LED with a transistor.Figure 2.2: Received data signal at the output of the receiver.

Figure 3.1:Circuit diagram of our design using PIC16F877.Figure 3.2: Receiver circuit.Figure 3.3: Received signals.Figure 3.4: General view of PIC16F877.Figure 3.5: General information about PIC16F877 pins.Figure 3.6: The transmitter circuit.Figure 3.7: Carrier signal (38 Khz).

Figure 3.8: Internal Block Diagram of NE555 Timer.Figure 3.9: A linear regulator (LM7805).Figure 4.1: Flowchart of software of remote controller.Figure 4.2: NEC protocol.Figure 4.3: A typical pulse train of the NEC protocol.Figure 4.4: Bits of the VCD Players buttons.Figure 4.5: Bit length of logic 0.Figure 4.6 : Bit length of logic 1.Figure 4.7: Bits of the Heaters buttonsFigure 4.8 PC InterfaceFigure 5.1. The wireless module

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Chapter 1INTRODUCTION

In this project we study infrared (IR) receiver and transmitter and also

protocols of remote controllers. The remote controller is controlled with PIC16F877.

With most pieces of consumer electronics, from camcorders to stereo equipment, aninfrared remote control is usually always included.Video and audio apparatus,

computers and also lighting installations nowadays often operate on IR remote

control.The carrier frequency of such IR signals is typically in the order of around 36

kHz. The control codes are sent in serial format modulated to 36 kHz carrier

frequecy (usally by turning the carrier on and off).There are many different coding

systems in use, and generally different manufacturers use different codes and

different datarates for transmission. Infrared light is invisible since its frequency isbelow that of visible red. Otherwise, it is like any other light source, operating under

the same laws of physics. In most cases, the IR signals are produced by a LED

source. TV remotes send commands only one way, in a low-speed burst for distances

of up to 30 feet. They use directed IR with LEDs that have a moderate cone angle to

improve ease-of-use characteristics. The IR signal sent out by those devices is

generally modulated to around 38 kHz carrier using amplitude shift keying (carrier

on or off). The data rate send is generally in the range of 100-2000 bps.

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Chapter 2

THEORETICAL FOUNDATIONS INFRARED (IR)RADIATION

2.1 Infrared (IR)Ligths

Infrared (IR) radiationis a particular kind of light. If we combine infraredradiation with radio waves, microwaves,visible light, ultraviolet radiation, X rays,

and gamma rays, we'll end up with a broad band of radiation frequencies called the

electromagnetic spectrum. All of these types of electromagnetic radiationtransfer

energy through space via waves of oscillating electromagnetic fields. What

distinguishes them from each other are the frequency of the oscillation and,

consequently, thewavelength.

An object's molecules and electrons are always in motion, vibrating and

radiating electromagnetic waves. When the object heats up and its temperature

increases, the motion will increase and so will the averagewave frequencyand the

intensity of the radiation. We can see this at work in a toaster oven. When we turn

the toaster on, we can feel some heat, but see no light. As more electric energy is

supplied and the wires get hotter, they begin to glow red. If we could really turn up

the power so that the temperature reached about 3,000 C, the wires, like the filament

in a light bulb, would glow white. The only problem is that they would probably burn

up before they reached that temperature.

2.2. IR Remote Controllers

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http://www.reachoutmichigan.org/funexperiments/agesubject/lessons/newton/infrared.html#infraredhttp://www.reachoutmichigan.org/funexperiments/agesubject/lessons/newton/infrared.html#visiblehttp://www.reachoutmichigan.org/funexperiments/agesubject/lessons/newton/infrared.html#spectrumhttp://www.reachoutmichigan.org/funexperiments/agesubject/lessons/newton/infrared.html#radiationhttp://www.reachoutmichigan.org/funexperiments/agesubject/lessons/newton/infrared.html#wavelengthhttp://www.reachoutmichigan.org/funexperiments/agesubject/lessons/newton/infrared.html#wavefrequencyhttp://www.reachoutmichigan.org/funexperiments/agesubject/lessons/newton/infrared.html#infraredhttp://www.reachoutmichigan.org/funexperiments/agesubject/lessons/newton/infrared.html#visiblehttp://www.reachoutmichigan.org/funexperiments/agesubject/lessons/newton/infrared.html#spectrumhttp://www.reachoutmichigan.org/funexperiments/agesubject/lessons/newton/infrared.html#radiationhttp://www.reachoutmichigan.org/funexperiments/agesubject/lessons/newton/infrared.html#wavelengthhttp://www.reachoutmichigan.org/funexperiments/agesubject/lessons/newton/infrared.html#wavefrequency


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IR is interesting, because it is easily generated and does not suffer

electromagnetic interference, so it is nicely used for communication and control,

however it is not perfect, some other light emissions could contain IR as well, and

that can interfere in this communication. The sun is an example, since it emits a wide

spectrum of radiation. Lots of things can generate IR, anything that radiate heat do it,

including our body, lamp, stove, oven, car's engine, car's tires, hot asphalt and rocks,

plants, even the hot water at the faucet. The massive use of IR LEDs at TV/VCR

remote controls and other applications, brought IR diodes and transistors (emitter and

receivers) at very low cost at the market. To allow a good communication using IR,

and avoid those "fake" signals, it is imperative to use a "key" that can tell the

receiver what is the real data transmitted and what is generated by the surroundingenvironment. As an analogy, looking eye naked to the night sky we can see hundreds

of stars, but we can spot easily a far away airplane just by its flashing strobe light,

even if that blinking light is dimmer than the stars lights. That strobe light is the

"key", the "coding" element that alerts us.

Similar to the airplane at the night sky, the room where the TV is installed

may have hundreds of tiny IR sources, our body, the lamps around, even the hot cupof tea. A way to avoid all those other sources, is generating a key, like the flashing

airplane. Thus, remote controls use to pulsate its infrared in a certain frequency. The

IR receiver module at the TV, VCR or stereo "tunes" to this certain frequency and

ignores all other IR signals received. The best frequency for the job is between 30

and 60 kHz, the most used is around 36 kHz. It works exactly as a radio tuning to a

specific station. In this case, the receiver tunes to the IR "radio" at 36 kHz, and

ignores the rest. Your cup of hot tea generates IR, but not at 36 kHz, it is flat andplain IR emission, and then, ignored by the TV IR receiver. Therefore, remote

controls use the 36 kHz (or around) to transmit information. IR light emitted by IR

diodes is pulsated at 36 thousand times per second, when transmitting logic level "1"

and silence for "0". To generate a 36 kHz pulsating IR is quite easy, more difficult is

to receive and identify this frequency. This is why some companies produce IR

receivers, that contains the filters, decoding circuits and the output shaper, that

delivers a square wave, meaning the existence or not of the 36kHz incoming

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pulsating infrared. It means that those 3 dollars small units, have an output pin that

goes high (+5V) when there is a pulsating 36 kHz IR in front of it, and zero volts

when there is not this radiation. A square wave of approximately 27 uS

(microseconds) injected at the base of a transistor, can drive an IR LED to transmit

this pulsating light wave. Upon its presence, the commercial receiver will switch its

output to high level (+5V).

Figure 2.1: Transmitting data signal by driving an IR LED with a transistor.

If we can turn on and off this frequency at the transmitter, our receiver's

output will indicate when the transmitter is on or off.

Figure 2.2: Received data signal at the output of the receiver.

IR demodulators have inverted logic at their outputs. When a burst of IR is

sensed they drive their outputs to low level, meaning logic level = 1. To avoid a

Philips remote control to change channels in a Panasonic TV, they use different

codification at the IR, even that all of them use basically the same transmitted

frequency, from 36 to 40 kHz. Thus, all of them use a different combination of bits to

avoid interference.

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Chapter 3HARDWARE DESIGN

3.1. Proteus Design

In the schematic(Figure 3.1), MAX232 is used as a wireless module. It has

nearly the same pin configuration. Receiver pin (RX) of the wireless module isconnected to microprocessors transmitter pin 25 (TX) and TX of the wireless

module is connected to pin 26 (RX) of the microprocessor. 4 MHz crystal is used for

microprocessor (PIC16F877). LM555 Timer is used for getting 38 kHz carrier

frequency.

RA0/AN02

RA1/AN13

RA2/AN2/VREF-4

RA4/T0CKI6

RA5/AN4/SS7

RE0/AN5/RD8

RE1/AN6/WR9

RE2/AN7/CS10

OSC1/CLKIN13

OSC2/CLKOUT14

RC1/T1OSI/CCP2 16

RC2/CCP1 17

RC3/SCK/SCL 18

RD0/PSP0 19

RD1/PSP1 20

RB7/PGD 40RB6/PGC 39

RB5 38RB4 37

RB3/PGM 36RB2 35RB1 34

RB0/INT 33

RD7/PSP7 30RD6/PSP6 29RD5/PSP5 28RD4/PSP4 27RD3/PSP3 22RD2/PSP2

21

RC7/RX/DT 26RC6/TX/CK 25

RC5/SDO 24RC4/SDI/SDA 23

RA3/AN3/VREF+5

RC0/T1OSO/T1CKI 15

MCLR/Vpp/THV1

PIC16F877

X1CRYSTAL

10k

+5V

T1IN11

R1OUT12

T2IN10

R2OUT9

T1OUT 14

R1IN 13

T2OUT 7

R2IN 8

C2+

4

C2-

5

C1+

1

C1-

3

VS+ 2

VS- 6

U2

MAX232

C5

22p

C6

22p

C9

1u

C1 0

1u

C1

1uC2

1u

162738495

J1

CO

R4

DC 7

Q 3

GND

1

VCC

8

TR2 TH 6

CV5

U3

NE555

RV 1POT

RV 2POT

R1

1kC4

100n

C9100n

+5V

Q1BC337

R2100R

D4DIODE-LED

+5V

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Figure 3.3: Received signals.

3.3. PIC16F877

A PIC16F877 Microcontroller includes 8 kb of internal flash Program

Memory, together with a large RAM area and an internal EEPROM. An 8-channel

10-bit A/D converter is also included within the microcontroller, making it ideal for

real-time systems and monitoring applications. All port connectors are brought out to

standard headers for easy connect and disconnect. In-Circuit program download is

also provided, enabling the board to be easily updated with new code and modified

as required, without the need to remove the microcontroller.

All the necessary support components are included, together with a Power

and Programming LED for easy status indication. Plus a reset switch for program

execution and a RS232 connection for data transfer to and from a standard RS232

port, available on most computers.

The new PIC16F877 Controller is the ideal solution for use as a standard

controller in many applications. The small compact size combined with easy

program updates and modifications, make it ideal for use in machinery and control

systems, such as alarms, card readers, real-time monitoring applications and much

more. This board is ideal as the brains of your robot or at the center of your home-

monitoring system. Save time and money, by simply building your ancillary boards

and monitoring circuits around this inexpensive and easy to use controller.

3.3.1 Features

Includes Powerful Microchip PIC16F877 Microcontroller with 8kb Internal

Flash Program Memory

Operating Speed at 10MHz

Direct In-Circuit Programming for Easy Program Updates

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Up to 28 I/O points with easy to connect standard headers

RS232 Connection with MAX232

Internal EEPROM

8 Channel 10-bit A/D Convertor

One 16-bit Timer with Two 8-bit Timers

Power and Programming LED

Reset Button

Ideal as an Interchangeable Controller for Real-Time Systems

Figure 3.4: General view of PIC16F877.

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RA0-5 : Input/Output port ARB0-7 : Input/Output port BRC0-7 : Input/Output port CRD0-7 : Input/Output port DRE0-2 : Input/Output port EAN0-7 : Analog input portRX : USART Asynchronous Receive

TX : USART AsynchronousTransmitSCK : Synchronous serial clock inputSCL : Output for both SPI and I2C

modesDT : Synchronous DataCK : Synchronous Clock SDO : SPI Data Out ( SPI mode )SDI : SPI Data In ( SPI mode )SDA : Data I/O ( I2C mode )CCP1,2 : Capture In/Compare Out/PWM

OutOSC1/CLKIN : Oscillator In/Ecternal Clock InOSC2/CLKOUT : Oscillator Out/Clock Out

MCLR : Master Clear ( Active low Reset )Vpp : Programming voltage inputTHV : High voltage test mode controlVREF+/- : Reference voltageSS : Slave select for the synchronous

serial portT0CKI : Clock input to Timer0

T1OSO : Timer1 oscillator outputT1OSI : Timer1 oscillator inputT1CKI : Clock input to Timer1PGD : Serial programming dataPGC : Serial programming clock PGM : Low voltage programinng inputINT : External interruptRD : Read control for the parallel slave

portWR : Write control for the parallel slave

portCS : Select control for the parallel slavePSP0-7 : Parallel slave portVDD : Positive supply for logic and I/O pinsVss : Ground reference for logic and I/O

pins

Figure 3.5: General information about PIC16F877 pins.

3.4. Transmitter and Timer

To transmit the stored signal, we should generate a 38-40 KHz square wave

carrier signal to protect from other IR interferances. We used 555 Timer to generate

the carrier wave and modulation. We built the circuit in Figure 3.7. With

potentiometer, we are able to control the duty cycle and frequency of the carrier

wave. The 555 Timer modulates any signal which is applied from its 4th pin and

outputs the modulated signal from its 3rd pin.

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Figure 3.6: The transmitter circuit. Figure 3.7: Carrier signal (38 Khz).

Figure 3.8: Internal Block Diagram of NE555 Timer.

3.5 Linear Regulator

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In electronics, a linear regulator is a voltage regulator based on an active

device operating in its linear region. All linear regulators require an input voltage at

least some minimum amount higher than the desired output voltage. That minimum

amount is called the drop-out voltage. For example, a common regultor such as 7805

(Figure 3.10) has an output voltage of 5V. Its drop-out voltage is 2V. Its minimum

input voltage will be 7V.

Common solid-state series voltage regulators are the LM78XX(for positive

voltages) and LM79XX(for negative voltages) and common fixed voltages are 5V

and 12V. In this project we use LM7805 for 5V common voltage.

Figure 3.9: A linear regulator (LM7805).

Chapter 4

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SOFTWARE DESIGN

Not all the IR remote controls have similar characteristics; in fact most of them have different frequency carriers depending of the factory, or the model or the

protocol. Another point to consider is that depending on the trademark or model, it

can be seen a considerable difference in the total amount of bits which is transmitted

after switch is pressed. We could say that RC5 and NEC codes are important for the

system, which are generally employed in most of IR remote controls.

For an IR remote controller for a VCD player and heater, we developed a

software algorithm. This project can be made using either PIC16F877 or AT89C52.

@PIC creating 889 us is easy by the help of delay command but creating 889 us is a

bit harder than that if AT89C52 is chosen.

Three functions are created for the system. They are one,zero and toggle to

give microprocessor 1, 0 and toogle bits.

-This part is explained detailly Ahmet Tekins final year project.

Figure 4.1: Flowchart of software of remote controller.

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4.1 Software Design of VCD Player

4.1.1 Features: 8 bit address and 8 bit command length. Address and command are transmitted twice for reliability. Pulse distance modulation. Carrier frequency of 38kHz Bit time of 1.125ms or 2.25ms

Figure 4.2: NEC protocol.

The NEC protocol uses pulse distance encoding of the bits. Each pulse is a560s long 38kHz carrier burst (about 21 cycles). A logical "1" takes 2.25ms to

transmit, while a logical "0" is only half of that, being 1.125ms. The recommended

carrier duty-cycle is 1/4 or 1/3.

Figure 4.3: A typical pulse train of the NEC protocol.

The buttons for the VCD player is shown in Figure 4.4

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Button Address bits Inv. Address bits Command bit Inv.CommandbitsSTOP 00000000 11111111 00101000 11010111

PAUSE 00000000 11111111 11001000 00110111OPEN/CLOSE 00000000 11111111 00001000 11110111

PLAY 00000000 11111111 10001010 01110101FORWARD 00000000 11111111 01111000 10000111

BACK 00000000 11111111 01010000 10101111ZOOM 00000000 11111111 11100000 00011111

VOLUME UP 00000000 11111111 11000000 00111111VOLUME

DOWN 00000000 11111111 01000000 10111111

Figure 4.4: Bits of the VCD Players buttons.

4.2. Software Design of Heater

4.2.1 Features

Protocol has only logic 1 and logic 0.

Bit lengths of logic 1 and logic 0 are 1600 us.

5 address bits and 7 command bits.

Carrier frequency 38 kHz

It is more basic according to NEC protocol.

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Figure 4.5: Bit length of logic 0.

Figure 4.6 : Bit length of logic 1.

The buttons for the heater is shown in Figure 4.7.

Button Address bits Command bits

Power 00100 1011111

2 00100 1111110

3 00100 1111101

4 00100 1110111

5 00100 1111011

6 00100 1101111

Figure 4.7: Bits of the Heaters buttons

4.3 PC INTERFACE

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We designed a PC interface for communicating with VCD player and heater.

Figure 4.8 PC Interface

--These parts are explained detailly Ahmet Tekins final year project.

Chapter 5

WIRELESS MODULE

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5.1.Features

Figure 5.1. The wireless module

5.2 General Description

Nano WiReach is a secure serial-to-Wireless LAN device server module

that also acts as a bridge to connect serial devices to 802.11b/g Wireless LANs. It

includes the iChip CO2144 IP Communication Controller chip and Marvell

88W8686 WiFi chipset. It is packaged in RoHS-compliant ultra-slim form factor

and uses an industry standard pin-out.

Nano WiReach offers much more than many other device servers on the

market. It acts as a security gap between the application and the network; supports

up to 10 simultaneous TCP/UDP sockets; two listening sockets; a web server with

two websites; SMTP and POP3 clients; MIME attachments; FTP and TELNET

clients, and SerialNET mode for serial-to-IP bridging.

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Nano WiReach supports the SSL3/TLS1 protocol for secure sockets, HTTPS

and FTPS, WEP, WPA and WPA2 WiFi encryption.

Nano WiReach minimizes the need to redesign the host device hardware. It

easily inserts into headers on the host PCB and connects to an external antenna.

Minimal or no software configuration is needed for Nano WiReach to access the

Wireless LAN.

Connect Ones high-level AT+i API eliminates the need to add WiFi

drivers, security and networking protocols and tasks to the host application. TheAT+i SerialNET operating mode offers a true plug-and-play mode that eliminates

any changes to the host application.

Nano WiReach firmware the IP stack and Internet configuration

parameters are stored in an external flash memory. The module is power-efficient:

the core operates at 1.2V, while I/Os operate at 3.3V. Power Save mode further

reduces power consumption.

The II-EVB-363NW evaluation board provides an easy environment for

testing the Nano WiReach prior to designing it into your product.

5.3 Hardware

Size: 33.76 x 18.0 x 5.5 mm Core CPU: 32-bit RISC ARM7TDMI, low-leakage, 0.13 micron, running at

48MHz

Operating Voltage: +3.3V+/-10%

Operating Humidity: 90% maximum (non-condensing)

Operating Temperature Range: -40 to 85C (-40 to 185F)

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Power Consumption: Transmit 250mA @16dbm 235mA @12dbm (typical)

Receive 190mA (typical) Power Save mode 8mA

RF Connector: U.FL of Hirose

Connector: Low profile 30 pin Host Interface: TTL Serial, SPI and USB device. RMII Interface

RoHS-compliant; lead-free

5.4 Performance Specifications

Host Data Rate: up to 3Mbps in serial mode

Serial Data Format (AT+i mode): Asynchronous character; binary; 8 data

bits; no parity; 1 stop bit

SerialNET mode: Asynchronous character; binary; 7 or 8 data bits; odd,

even, or no parity; 1 stop bit

Flow Control: Hardware (-RTS, -CTS) and software flow control.

Wireless module is working with 3.3 volt and it has receiver pin (RX) to

receive data from PC and transmitter pin (TX) for transmitting data to

microprocessor. It has reset pin for starting the module again. When the data come to

data ready pin, it can choose the next operation to do.

5.5 Configuration

Wireless module is needed to configure for serial communication,getting IP

and some instructions below.

-AT+iWLSI=speedtouch

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The primary parameter governing the identity of the Access Point to which the

iChip will associate and connect to is theService Set ID entifier (SSID). Each Access

point has its own SSID value.Speedtouch is the SSID of our system.

-AT+iIPA=169.254.111.17

This command is used temporarily set the current IP address.

-AT+iLPRT=10017

Permanently sets the port number on which iChip will listen for client

connections in SerialNET mode. It could be such a number between 0 and 65536.

-AT+iHIF=1

Specifies the interface to be used for communication between the host

processor and iChip in subsequent sessions. If it is 1, USART0 can be used in the

system.

-AT+iMTTF=250

Sets max inactivity timeout before flushing the SerialNET socket.

-AT+iSNMD=3 Activates SerialNET mode. When this flag is specified, iChip automatically

goes online.

However, if the HSRV parameter is defined, a socket is not opened until data

arrive on the local serial port.

Chapter 6

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RESULTS and CONCLUSIONS

IR signals are used to carry data, and the most popular application area isremote controller which is used on TV, DVD player, air conditioner etc. Some

remote controllers use RF signals like car and garage remote controller. This is one

of the advantages of the IR signals because IR signals are effective at short distance

and transmitter and receiver must see each other.

IR communication is done by using protocol like SONY, NEC, RC5.

Protocols determine the length of the pulses. We use NEC protocol for VCD player

and another protocol which is looking like RC5 in our design. Software and making

timer was designed according to protocols. In this project, IR pulses are sent through

the device. We send data from PC to microcontroller and then microcontroller send

them to controlled device via IR LED. This was done by the original algorithm

which was explained in previous chapters.

One of the important problems is the noise. IR transmitter module can get a

signal from daylight which consist a lot of frequency components. This problem was

encountered and system works successfully.

IR remote controller was designed for 38 KHz signals. But we change that

value a little to be near 37.5 KHz. At that point it can be asked if the transmitted

signal is not modulated at 38 KHz, would this circuit still work? To answer this

question the effect of the carrier frequency of the IR signal must be known. Of

course if a circuit is designed for a special carrier frequency, it does not respond toanother signal which is modulated with a different frequency. But if the transmitted

signal is modulated with a closer frequency band of the carrier frequency, the circuit

responds. For example, if message signal is modulated with 37 KHz, circuit will

work again but there will be a difference of two signals on the circuit. It can

communicate with the remote controller with 38 KHz modulation at a longer

distance than 37 KHz modulation. Hence the effect of the carrier frequency on

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distance can be seen with different devices which have different modulation

frequencies.

Finally, IR technologies make the daily life with remote controller. All

remote controllers work with a special protocol. In this project, IR remote controller

gets the 32 bit data values from PC and sends them to VCD player and 12 bit data

values from PC and sends them to heater . It uses 2 protools while achieving this.

If we want, we can use SONY, RC5 and another protocol for another device. Our

designed circuit would be useful if you are far from our controlled device. For

example, if we forget closing our device, we can close or get it work in sleep mode.

This circuit designed in this project can be employed in futuristic smart homeprojects.

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REFERENCES

1. I. Scott MacKenzie , The 8051 Microcontroller, Second Edition, Prentice Hall,

Inc., 1995

2. http://www.sbprojects.com/knowledge/ir/ir.htm

3. http://www.ustr.net/infrared/index.shtml

4. http://www.datasheetcatalog.com5 . http://www.rentron.com/Infrared_Remote_Control.htm

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