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CHAPTER 1

INTRODUCTION

1.1 GENERAL DESCRIPTION

The need of power consumers increasing rapidly meanwhile the renewable and

Non-renewable power generation are insufficient and the power wastage also swelling

highly in the absence of people. According to recent technology the research about energy

consumptions are increasing year by year, if effective energy saving policies will not be

adopted, then in 2030 they will double with respect to 1980 survey level and will increase

by 28% on 2006 survey level. The generation of the energy from the available resources is

not modest one because of the changes in environmental conditions. So we are responsible

for utilizing the power in efficient way to avoid the wastage of power. To reduce these

unwanted power wastage my proposed system will provide the solution by an automated

monitoring system.

The power wastages are most commonly occurs in organizations like Institutions,

Industries due to lack of awareness about power demands. In the existing system PIR,

LDR, temperature sensor are used to sense the human being, intensity of light ,

temperature respectively as per the reference, the author use ARM Processor and never

used timetable. The proposed system can be designed based on FPGA. A field

programmable gate array (FPGA) contains a matrix of reconfigurable gate array logic

circuitry that, when configured, is connected in a way that creates a hardware

implementation of a software application. FPGAs use dedicated hardware for processing

logic and do not have an operating system. Because the processing paths are parallel,

different operations do not have to compete for the same processing resources. That means

speeds can be very fast, and multiple control loops can run on a single FPGA device at

different rates. The embedded processors are using sequential processing. Due to this, the

system can able to monitoring only one section at particular time period. But the FPGA

operates at parallel processing. It can able to control over all process at particular time

period. And also the memory level in FPGA is high, when compare to other processors.

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The timetable can be used many places like college, company and industries to

using standardize working hour. The proposed system considers the timetable of class

room since students are present only for 75% of the working hours. In the remaining hours

they move to other places like libraries, laboratories. The following table discusses the

major situation where power is wasted if students forget to switch OFF the electrical

appliances.

Table 1. Summarization of Power loss in an institutions

So I propose an automated system that can control the usage of electricity in the

classroom environment where maximum electricity is wasted.

Purpose for which students moving from classroom

Time for which

the electricity

is to be wasted

Laboratories

3 Hours

Break hours( Normally 3 Breaks per day)

1 Hours

Moving to home at the end of day

15 Hours

(till next day

morning)

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1.2 BLOCK DIAGRAM

The classroom Automated Monitoring System is controlled by FPGA (SPARTAN

6) as shown in below.

Figure 1. Block Diagram of Automated Power Controlling System

Initially timetable is set as primary in this system. Time table of class for all days

are written in VHDL and fed into the Spartan-6 FPGA. There is possible to select the

timetable as per our requirement using keyboard and it will display in Character 16x2

LCD. A real time clock will be displayed in 7segment for checking whether the time table

operates for proper time. Then the PIR sensor continuously senses the temperature level at

particular area and produces the output and fed into FPGA. When students entering into the

Passive Infra-Red

Sensors (To detect the

human presence)

LDR SENSOR

(To measure the

light intensity)

RELAY 1

RELAY 2

FP

GA

(S

PA

RT

AN

6)

FAN

LIGHT

LM35

(To measure the

room temperature)

CONTROL

CIRCUIT

KEYBOARD

(To enter the

Time table)

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monitored area, the temperature level measured by PIR will vary and PIR sensor output

made high. In accordance with class timetable and PIR output (high) then LDR sensor

checks the room lightening, if the light is insufficient, the LDR acts as a resistor with high

resistance (in Mega Ohms), so the output low. The FPGA detects low output and switch

ON the light. LM35 sensor senses the room temperature and produces the output. It will

produce 10mV/C. The temperature sensor output fed into FPGA using ADC and the speed

of the fan varies according to the temperature level.

1.3 HARDWARE DESCRIPTION

1.3.1 Spartan6 Xc6slx25t FPGA

Field-Programmable Gate Arrays (FPGAs) are pre-fabricated silicon devices that

can be electrically programmed to become almost any kind of digital circuit or system.

They provide a number of compelling advantages over fixed-function Application Specific

Integrated Circuit (ASIC) technologies such as standard cells [62]: ASICs typically take

months to fabricate and cost hundreds of thousands to millions of dollars to obtain the first

device; FPGAs are configured in less than a second (and can often be reconfigured if a

mistake is made) and cost anywhere from a few dollars to a few thousand dollars. The

flexible nature of an FPGA comes at a significant cost in area, delay, and power

consumption: an FPGA requires approximately 20 to 35 times more area than a standard

cell ASIC, has a speed performance roughly 3 to 4 times slower than an ASIC and

consumes roughly 10 times as much dynamic power [120]. These disadvantages arise

largely from an FPGAs programmable routing fabric which trades area, speed, and power

in return for instant fabrication.FPGA architecture has a dramatic effect on the quality of

the final devices speed performance, area efficiency, and power consumption.

Spartan-6 FPGA delivers an optimal balance of low risk, low cost, and low power

for cost-sensitive applications, now with 42% less power consumption and 12% increased

performance over previous generation devices. Spartan-6 FPGAs offer advanced power

management technology, up to 150K logic cells, integrated PCI Express blocks,

advanced memory support, 250MHz DSP slices, and 3.2Gbps low-power transceivers.

Spartan-6 FPGA Family Benefits are intelligent mix of hard IP and programmability for

greater integration, Differentiate products through efficient power management, easily

meet system-level requirements.

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1.3.2 PIR Motion Detector

Infrared sensors can be classified as active infrared sensors and passive infrared

sensors. Both of them use the same infrared rays the only difference between them is,

active infrared sensors employ infrared source (an active element) in addition to infrared

detector. Active infrared sensors operate by transmitting energy from either a light emitting

diode (LED) or a laser diode. A LED is used for a non-imaging active IR detector, and a

laser diode is used for an imaging active IR detector. In both types of these, the LED or

laser diode illuminates the target, and the reflected energy is focused onto a detector

consisting of a pixel or an array of pixels. Photoelectric cells, Photodiode or

phototransistors are generally used as detectors. Passive Infrared sensors does not contain

any source of infrared radiation, they simply detect IR radiations. They totally rely on the

three governing laws explained earlier. A passive infrared system detects energy emitted

by objects in the field of view it does not emit any energy of its own for the purposes of

detection.

Human at normal body temperature radiate quite strongly in the infrared region at a

wavelength around 10 m. Passive infrared sensors convert the infrared signal to current or

voltage. Its presence is hard to detect which is not the case with active infrared sensors,

ultrasonic detectors. Passive Infra-Red Sensors were originally being used for military and

Scientific applications.

Figure 2. PIR Sensor

PIR sensor is made of ceramic material that generates surface charge when exposed

to infrared radiations. As the amount of radiation increase, the generations of surface

charge also increase. A FET is used to buffer this signal. As the sensor is sensitive to a

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wide range of radiations, a filter is used which limits the infrared rays falling on the sensor

from 8um-14um range. Thus the output of an IR sensor is a function of infrared radiation.

The field of view of these sensors is the area or zone where changes in the infra-red

radiation can be sensed or detected. Typically, to enhance the range and field of view, the

field of view is divided into number of zones (both vertically as well as horizontally) with

the help of Fresnel lens. A Fresnel lens is a Plano convex lens that is collapsed itself to

form a flat lens which retains its optical properties, but it is thinner and less absorption

loss. Multi Element Fresnel Lens focuses the infra-red radiation emitted by an infrared

source onto the PIR detector. After the light falls on the PIR sensor, it generates an

electrical signal corresponding to infrared radiations which is amplified/ processed and in

turn may energize a relay. In most of the applications, passive infrared sensors look for the

change in the environment. The sensors are sensitive to changes in infrared energy rather

than absolute levels. Typical construction of PIR is shown in figure 3.

Figure 3. Construction of a PIR Sensor

The sensor first sets up equilibrium with the background conditions. If the state

equilibrium is disturbed due to some intrusion or by some other mechanism, it perceives it

as a change. This change is fundamental to the operation of PIR sensors. By dividing the

region into a number of zones, numbers of separated zones are created. A person while

walking through the area will appear in one zone, then disappear and then reappear in the

next zone and so on. By doing so, he modulates the reference equilibrium conditions; the

process is referred to as chopping. The signal produced is proportional to the temperature

difference between the intruder and the background.

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A PIR detector is a motion detector that senses the heat emitted by living body.

These are often fitted to security light so that they will switch on automatically if a person

approaches the monitored area. The senor is passive because, instead of emitting a beam of

light or microwave energy that must be interrupted by a passing person in order to sense

that person. The PIR sensor itself has two slots in it, each slot is made of a special material

that is sensitive to IR. When the sensor is idle, both slots detect the same amount of IR, the

ambient amount radiated from the room or walls or outdoors. . The operation schematic of

PIR is shown in figure 4.

Figure 4. Operation of PIR

When the human passes the monitored area, it first intercepts one half of the PIR

sensor, which causes a positive differential change between the two halves. When the

human leaves the sensing area, the reverse happens, whereby the sensor generates a

negative differential change. These change pulses are what is detected. The PIR itself is

housed in a hermetically sealed metal can to improve noise/temperature/humidity

immunity. There is a window made of IR-trans missive material (typically coated silicon

since that is very easy to come by) that protects the sensing element. Behind the window

are the two balanced sensors. The technical parameter of PIR is shown in table 2.

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Power Supply DC9V

Transmission Current 20Ma

Frequency 433MHZ

Detective Speed 0.3 3m/s

Detective Distance 5 12M

Detective Range Horizontal 110, Vertical 60

Working Condition Temperature 10 to + 40

Table 2. Technical Parameters of PIR

1.3.3 LDR ( Light Dependent Resistors )

LDRs or Light Dependent Resistors are very useful especially in light/dark sensor

circuits. Normally the resistance of an LDR is very high, sometimes as high as 1000000

ohms, but when they are illuminated with light resistance drops dramatically. LDR are

made by depositing a film of cadmium sulphide or cadmium selenide on a substrate of

ceramic containing very few free electrons when not illuminated. When light falls on the

strip, the resistance decreases. In the absence of light the resistance can be in the order of

10K ohm to 15K ohm and is called the dark resistance. Depending on the exposure of light

the resistance can fall down to value of 500 ohms. The device consists of a pair of metal

film contacts separated by cadmium sulphide film, designed to provide the maximum

possible contact area with the two metal films. It has a peak sensitivity wavelength (p) of

about 560nm to 600nm in the visible spectral. Schematic of LDR shown in figure 5. When

an LDR is brought from a certain illuminating level into total darkness, the resistance does

not increase immediately to the dark value. The recovery rate is specified in k ohm/second

and for current LDR types it is more than 200 k ohm/second. The recovery rate is much

greater in the reverse direction, e.g. going from darkness to illumination level of 300 lux, it

takes less than 10ms to reach a resistance which corresponds with a light level of 400 lux.

Darkness: Maximum resistance, about 1M ohm.Very bright light: Minimum resistance,

about 100 ohms.

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Figure 5. Structure of LDR

1.3.3.1 Sensitivity

The sensitivity of a photo detector is the relationship between the light falling on

the device and the resulting output signal. In the case of a photocell, one is dealing with the

relationship between the incident light and the corresponding resistance of the cell. The

resistance functions as a illumination shown in figure 6.

Figure 6. Resistance Function as Illumination

1.3.4 LM35 Temperature Sensor

The LM35 is an integrated circuit sensor that can be used to measure temperature

with an electrical output proportional to the temperature (oC). It can measure temperature

more accurately than a using a thermistor. The sensor circuitry is sealed and not subject to

oxidation, etc. The LM35 generates a higher output voltage than thermocouples and may

not require that the output voltage be amplified. It has an output voltage that is

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proportional to the Celsius temperature. The scale factor is .01V/oC The LM35 does not

require any external calibration or trimming and maintains an accuracy of +/-0.4 oC at

room temperature and +/- 0.8 oC over a range of 0 oC to +100oC. Another important

characteristic of the LM35DZ is that it draws only 60 micro amps from its supply and

possesses a low self-heating capability. The sensor self-heating causes less than 0.1 oC

temperature rise in still air.

Figure 7. LM35 Temperature Sensor

1.3.5 LCD Display

LCD is a type of display used in digital watches and many portable computers.

When an electric current passed through the liquid causes the crystals to align so that light

cannot pass through them. LCD has two line displays each can represent 20 characters per

line. The liquid crystals can be manipulated through an applied electric voltage so that light

is allowed to pass or is blocked. By carefully controlling the density of light passed

through LCD which is also used to display images. A backlight provides LCD monitors

brightness.

Figure 8. Pin Diagram of LCD

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The Liquid Crystal Display (LCD) is a low power device. The power

requirement is typically in the order of microwatts for the LCD. However, an LCD

requires an external or internal light source. LCD is used to display the PIR mode and

room temperature. A 14-pin access is provided having eight data lines, three control lines

and three power lines.

1.3.6 Power Supply

1.3.6.1 12Vac Step down Transformer

Figure 9. 230Vac TO 5Vdc CONVERTER

The Voltage Transformer can be thought of as an electrical component rather than

an electronic component. The main purpose of a voltage transformer is to transfer

electrical power between different circuits by converting one AC voltage source into

another AC voltage at the same frequency. Transformers are basically mechanical devices

that consist of one or more coil(s) of wire wrapped around a common ferromagnetic

laminated core. These coils are usually not electrically connected together however, they

are connected magnetically through the common magnetic flux Qm confined to a central

core. Voltage transformers work on Faradays principal of electromagnetic induction.

When a current flows through a coil, a magnetic flux () is produced around the coil. If we

now place a second similar coil next to the first so that this magnetic flux cuts the second

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coil of wire, an e.m.f. voltage will be induced in the second coil. This effect is known as

mutual induction and is the basic operation principal of voltage transformers. The value

of the induced e.m.f in the second coil is proportional to the number of turns and to the rate

of change of magnetic flux. In a voltage transformer these two coils known as

the primary and secondary windings are tightly wrapped around a single core material such

as steel or iron which improves the magnetic coupling between these two coils. Therefore,

each coil has the same number of volts per turn in it producing two different voltages that

are proportional to each other.

The frequency of the secondary waveform will be in-phase with the frequency of

the primary waveform then the cos term cancels out on both sides of the above equation.

We now know that the output voltage from the secondary winding is directly proportional

to the number of turns of wire in the secondary coil. If we increase or decrease this number

of turns, a larger or smaller voltage will be induced into the secondary winding. Then we

can define the Turns Ratio as the number of windings of the primary coil (Np) divided

by number of windings of the secondary coil (Ns). Then the ratio of the primary and

secondary voltages is the same as the ratio of the number of turns in each winding. This

ratio is known commonly as the transformation Ratio and is presented as Np:Ns (no units

as it is a ratio). Then voltage transformers are all about ratios, that is the ratio of windings

called the turns ratio to the ratio of the voltage called the voltage ratio.

If this turns ratio is equal to one (unity) that is the number of secondary turns

equals the number of primary turns giving a turns ratio of 1:1, the secondary voltage will

be of the same value as the primary voltage producing an isolation transformer. However,

if the ratio is greater than unity, and Vs is greater than Vp, this produces a step up

transformer. Likewise, if the ratio is less than unity, and Vs is less than Vp, this produces

a step down transformer.

Then we can define the operation of a voltage transformer as:

Step down Voltage Transformer

Number of primary turns > Number of secondary turns

Primary voltage > Secondary voltage

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Step up Voltage Transformer

Number of primary turns < Number of secondary turns

Primary voltage < Secondary voltage

Transformers do not change power they transfer the same amount of power

(assumes ideal transformer) from the primary side to the secondary side. As electrical

power is the product of volts x amps, if the voltage changes then the current must change

to maintain the same amount of power. That is the current changes opposite to the voltage

change and if one goes up, the other goes down. So if the secondary voltage is greater than

the primary voltage then the secondary current is less than the primary current. If the

secondary voltage is less than the primary voltage then the secondary current is greater

than the primary current. This is called the current ratio and is opposite to the previous

voltage and turns ratios. Then transformers are all about ratios, the ratio of the input

(primary) turns, volts and amps to the output (secondary) turns, volts and amps.

1.3.6.2 Bridge Rectifier

When four diodes are connected as shown in figure, the circuit is called a BRIDGE

RECTIFIER. The input to the circuit is applied to the diagonally opposite corners of the

network, and the output is taken from the remaining two corners. One complete cycle of

operation will be discussed to help you understand how this circuit works. We have

discussed transformers in previous modules in the NEETS series and will not go into their

characteristics at this time. Let us assume the transformer is working properly and there is

a positive potential at point A and a negative potential at point B. The positive potential at

point A will forward bias D3 and reverse bias D4.

The negative potential at point B will forward bias D1 and reverse bias D2. At this

time D3 and D1 are forward biased and will allow current flow to pass through them; D4

and D2 are reverse biased and will block current flow.

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Figure 10. Operation of Bridge Rectifier

The path for current flow is from point B through D1, up through RL, through D3,

through the secondary of the transformer back to point B. This path is indicated by the

solid arrows. Waveforms (1) and (2) can be observed across D1 and D3.

One-half cycle later the polarity across the secondary of the transformer reverses,

forward biasing D2 and D4 and reverse biasing D1 and D3. Current flow will now be from

point A through D4, up through RL, through D2, through the secondary of T1, and back to

point A. This path is indicated by the broken arrows. Waveforms (3) and (4) can be

observed across D2 and D4. You should have noted that the current flow through RL is

always in the same direction. In flowing through RL this current develops a voltage

corresponding to that shown in waveform (5). Since current flows through the load (RL)

during both half cycles of the applied voltage, this bridge rectifier is a full-wave rectifier.

One advantage of a bridge rectifier over a conventional full-wave rectifier is that

with a given transformer the bridge rectifier produces a voltage output that is nearly twice

that of the conventional full-wave circuit. This may be shown by assigning values to some

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of the components shown in views A and B. Assume that the same transformer is used in

both circuits. The peak voltage developed between points X and Y is 1000 volts in both

circuits. In the conventional full-wave circuit shown in view A, the peak voltage from the

center tap to either X or Y is 500 volts. Since only one diode can conduct at any instant,

the maximum voltage that can be rectified at any instant is 500 volts. Therefore, the

maximum voltage that appears across the load resistor is nearly - but never exceeds - 500

volts, as a result of the small voltage drop across the diode. In the bridge rectifier shown in

view B, the maximum voltage that can be rectified is the full secondary voltage, which is

1000 volts. Therefore, the peak output voltage across the load resistor is nearly 1000 volts.

With both circuits using the same transformer, the bridge rectifier circuit produces a higher

output voltage than the conventional full-wave rectifier circuit.

1.3.6.3 IC 7805 Voltage Regulator

7805 is a voltage regulator integrated circuit. It is a member of 78xx series of fixed

linear voltage regulator ICs. The voltage source in a circuit may have fluctuations and

would not give the fixed voltage output. The voltage regulator IC maintains the output

voltage at a constant value. The xx in 78xx indicates the fixed output voltage it is designed

to provide. 7805 provides +5V regulated power supply. Capacitors of suitable values can

be connected at input and output pins depending upon the respective voltage levels.

Figure 11. IC7805

Pin Description:

Pin No Function Name

1 Input voltage (5V-18V) Input

2 Ground (0V) Ground

3 Regulated output; 5V (4.8V-5.2V) Output

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1.3.7 UTLP Kit

Unified Learning Kit is based on Texas Instruments OMAP3530 application

processor & Spartan-6 FPGA.

The OMAP3530 processor supports interfaces such as Mobile DDR, Nand

Flash, Audio in & out, TV out, Touch screen LCD, VGA out, Ethernet, Keypad, USB

OTG, 2 SD cards & external interface connectors such as Control sensor header, I/O

expansion connector, I2C Header for GPS, Bluetooth & Modem Connector, Simple Digital

Interface connector (SDI), Camera Connector & LCD connector.

The Spartan-6 FPGA supports interfaces such as DDR2 SDRAM, Ethernet,

ADC, DAC, character LCD & external interfaces such as 70-pin IO expansion connector

& 20-pin IO header. The ULK board and its block diagram are shown in figure 12

respectively.

The software can be used for designing the board is Eclipse and Xilinx and the

code used for programming is based on the basic C language and HDL. The board input

voltage is about 2V. The output can be processed in Minicom or in the ULK Control Panel.

The Minicom is operated in lab mode and the control panel is operated in normal mode.

The output voltages can be obtained from external interfaces such as Simple Digital

Interface (5V). The advantage of this kit is modest for connecting external interfaces,

programming is simple and using these features various applications can be designed based

on the requirements of the user.

1.3.7.1 OMAP 3530 Processor

TIs OMAP3530 application processor with CUS package

TIs TPS65930 Power management IC

NAND Flash Memory of 128Mbytes

Mobile DDR SDRAM of 128Mbytes

Ethernet controller with 10/100Mbps PHY and RJ45 LAN connector

USB2.0 OTG interface

2 no.s of SD interface

RS232 Console using UART1&3

Real Time Clock

CMOS sensor interface

24 bit RGB LCD interface

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Mic in and speaker out

Touch panel controller through SPI interface

3.5inch LCD interface

I2C EEPROM of 256Kbits

IrDA support using UART3

Bluetooth & modem connector (3.3V compatible)

16x2 Character LCD using I2C to I/O bus expander

Figure 12. Block Diagram of ULK

JTAG interface

6x6 Keypad interface (Using PMIC)

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Simple digital interface with 5V compatible

Control sensor connector with 5v compatible

I/O Expansion connector as same as beagle board through level

translators (1.8 to 3.3V/5V) for 3.3V & 5V compatible

One I2C,SPI & GPIO signals between processor and FPGA

GPMC bus between processor and FPGA

Reset device and manual reset button

1.3.7.2 Spartan-6 FPGA

Xilinx XC6SLX25T FPGA

SPI PROM from Atmel (2Mbyte)

I2C EEPROM of 256Kbits

10/100Mbps Ethernet PHY and RJ45 LAN connector

14 pin connector

UART transceiver

4x4 Keypad interface

16x2 character LCD through parallel interface

10bit ADC with parallel interface

7 segment LEDs

70-pin I/O expansion connector

1.3.7.2.1 ADC Interface

The 10-bit, 20MSPS sampling analog to digital converter AD9200 from Analog

devices is used to interface with FPGA through 10 bit parallel interface. The AD9200 is

configured Top/Bottom mode by connecting mode pin to AVDD and analog input level is

set by using REFTS, REFBS signals. The internal reference voltage (Vref) is configured in

2V mode. The FPGA-ADC interface shown in figure 13.

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Figure 13. FPGA-ADC Interface

1.3.7.2.2 Character LCD Interface

The 8-bit parallel interface logic will be developed inside the FPGA to configure

the HD44780 based dot matrix LCD controller for the character LCD support. Since the

LCD's consume less power, they are compatible with low power electronic circuits.

Changing the display size or the layout size is relatively simple which makes the LCD's

more customer friendly. The FPGA-Character LCD interface shown in figure 14.

Figure 14. FPGA-Character LCD Interface

1.3.7.2.3 DAC interface

The 12-bit, 10MSPS sampling digital to analog converter DAC7821 from TI is

used to interface with FPGA through 12 bit parallel interface. It provides single channel

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current output. The bidirectional bus is controlled with CS# and R/W# signal to read/write

into/from DAC. The control signals will be generated from FPGA. Op Amp OPA348 is

used to convert the current output of DAC to voltage output.

Figure 15. FPGA-DAC Interface

1.3.7.2.4. 20-Pin FPGA IO header

Level Translators are used to convert the 1.8V FPGA signals to 5V compatible

signals.

Figure 16. FPGA-20-Pin IO Header

1.3.7.2.5. FPGA Keypad interface

To support 4rows x 4columns keypad interface, keypad scanning and

debouncing logic is developed inside the FPGA. The I/O signals of FPGA will be

used and signals are taken out to the 12pin 2.54mm pitch header.

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Figure 17. FPGA Keypad Interface

1.3.7.2.6 7 Segment LED interface

To display 4 digit 7 segment LEDs, LTC-4627JR device is used from Lite-

On electronics. LTC-4627JR is a common anode device. FPGA I/O's are used to

drive the cathodes and common anodes of the 7 segment LED display.

Figure 18. FPGA 7 Segment Display

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1.4 SOFTWARE DESCRIPTION

1.4.1 XILINX 12.1

Xilinx ISE (Integrated Software Environment) is a software tool produced

by Xilinx for synthesis and analysis of HDL designs, enabling the developer to synthesize

their designs, perform timing analysis, examine RTL diagrams, simulate a design's reaction

to different stimuli, and configure the target device with the programmer. HDL can be

classified as two parts. They are

VHDL (Very High Speed Integrated Circuit Hardware Description Language)

Verilog HDL

Figure 19. Xilinx 12.1 Work Flow

Design Entry

Design

Synthesis

Design

implementation

Xilinx Device

Programming

Design Verification

Behavioural Simulation

Functional Simulation

Static Timing Analysis

Timing Simulation

In-Circuit Verification

Back

Annotation

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1.4.2 ULK Control Panel

ULK Control Panel is a software which is used for implementing the Xilinx Sector

Vector File (XSVF) into the UTLP kit. After synthesis process, the Xilinx would create the

xsvf file in generate programming process. An Ethernet cable used for interfacing the

UTLP kit with computer. After the xsvf file creation, it would be transferred through

Ethernet from computer to UTLP kit. By using ULK control panel the designer can able to

interface more number of UTLP kits with computer. For each UTLP kit we have to assign

separate IP address. The UTLP Kit only supports for ubuntu 10.10. So the ULK control

panel and Xilinx 12.1 software designed for only supporting Ubuntu platform.

1.5 IEEE FLOATING POINT ALGORITHM

IEEE 754 floating point is the most common representation today for real numbers

on computers. There are several ways to represent real numbers on computers. Fixed point

places a radix point somewhere in the middle of the digits, and is equivalent to using

integers that represent portions of some unit. For example, one might represent 1/100ths of

a unit. If you have four decimal digits, you could represent 10.82, or 00.01. Floating-point

representation basically represents reals in scientific notation. Scientific notation represents

numbers as a base number and an exponent. For example, 123.456 could be represented as

1.23456 x 102. In hexadecimal, the number 123.abc might be represented as 1.23abc x 162.

Floating-point solves a number of representation problems. Fixed-point has a fixed

window of representation, which limits it from representing very large or very small

numbers. Also, fixed-point is prone to a loss of precision when two large numbers are

divided. On the other hand, floating-point employs a sort of "sliding window" of precision

appropriate to the scale of the number. This allows it to represent numbers from

1,000,000,000,000 to 0.0000000000000001 with ease.

IEEE floating point number have three basic components: the sign, the exponent,

and the mantissa. The mantissa is composed of the fraction and an implicit leading digit.

The exponent base (2) is implicit and need not be stored.

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There are two basic number formats in IEE754, single precision, and double

precision. In addition there are two extended formats, which are only used as intermediate

results while calculating. The following table shows the formats for single and double

precision floating-point values. The number of bits for each filed are shown (bit ranges are

in square brackets):

Sign Exponent Fraction

Single precision 1[31] 8[30-23] 23[22-0]

Double precision 1[63] 11[62-52] 52[51-0]

Table 3. IEEE Floating point formats precision

In sign bit 0 denotes a positive number; 1 denotes a negative number. Flipping the

value of this bit flips the sign of the number.

The exponent field needs t represent both positive and negative exponents. To do

this, a bias is added to the actual exponent in order to get the stored exponent. For IEEE

single-precision floats, this value is 127. For double precision, the exponent field is 11 bits,

and has a bias 1023.

For example, an exponent of zero in single precision means that 127 is stored in the

exponent field. A stored value of 250 indicates an exponent of (200-127), or 123.

The significant, represents the precision bits of the number. It is composed of an

implicit leading bit and the fraction bits.

In order to maximize the quantity of representable numbers, floating-point numbers

are typically stored in normalized form. This basically puts the radix point after the first

non-zero digit. An optimization is available in base two, since the only possible non-zero

digit is 1. Thus we can just assume a leading digit of 1, and dont need to represent it

explicitly. As a result, the mantissa has effectively 24 bits of resolution, by way of 23

fraction bits.

To sum up,

1. The sign bit is 0 for positive, 1 for negative.

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2. The exponents base is 2.

3. The exponent field contains 127 plus the true exponent for single-precision, or

1023 plus the true exponent for double precision.

4. The first bit of the mantissa (hidden bit) is typically assumed to be 1.

IEEE reserves exponent field values of all 0s and all 1s to denote special values in

floating-point scheme. Zero is not directly representable in te straight format, due to the

assumption of a leading 1. Zero is a special value denoted with an exponent field of zero

and a fraction field of zero. If the exponent is all 0s, but the fraction is non-zero, then the

value is a demoralized number, which does not have an assumed leading 1 before the

binary point. Thus, for single precision, this represents a number (-1) s x 0.f x 2-126, where

s is the sign bit and f is the fraction.

Example

Now, lets see some examples.

1. Convert 145.84375 to binary floating point numbers in IEEE single precision.

Step 1: convert 145.84357 to binary.

145 = 10010011 & .84375 = .11111

145.84375 = 10010011.11111

Step 2: normalize and note sign

145.84375 = (-1)0 1.001001111111 X 27

Step 3: calculate excess 127 code for exponent

e = 7 + 127 = 134 = 10000110

Step 4: Assemble

0 1 0 0 0 0 1 1 0 0 0 1 0 0 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0

2. Convert the IEEE 0 1 0 0 0 0 1 1 0 1 0 1 1 1 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 to decimal

number.

0 1 0 0 0 0 1 1 0 1 0 1 1 1 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

Step 1: calculate exponent to decimal

10000110 = 134

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Step 2: rewrite IEEE to (-1) sign 1.significand X 2EXP-127 format

(-1)0 1.1011101 X 2134-127

Step 3: normalize and convert to decimal

(-1)0 1.1011101 X 27 = + 1.1011101 X 27 = +11011101 = 22110

1.6 LITERATURE SURVEY

Chinnam Sujana, Adanki Puma Ramesh, P.Gopala Reddy, Automatic

Detection Human and Energy Saving Based Zigbee Communication,

International journal on computer science and engineering, volume 6,

2011

This magazine publisher, that automatically switches on the light and fan by

detection of human being. Depends upon the lightening the system can automatically

adjust the light intensity and based on the temperature it can switch ON/OFF the Fan. This

paper proposes automatic detection of human and Energy saving room architecture to

reduce standby power consumption and to make the room easily controllable with an IR

remote control of a home appliance. To realize the proposed room architecture, we

proposed and designed the Zigbee communication. Zigbee is a low-cost, low-power,

wireless mesh networking. The low cost allows the technology to be widely deployed in

wireless control and monitoring applications, the low power-usage allows longer life with

smaller batteries, and the mesh networking provides high reliability and larger range. The

proposed auto detection of human done using the IR sensor to indicate the entering or exit

of the persons. Microcontroller continuously monitors the infrared receiver. When any

object pass through the IR receiver then the IR rays falling on the receiver are obstructed,

this obstruction is sensed by the microcontroller (LPC2148-ARM7) also PIR sensor will

check the presence of human beings with the help of radiations emitted by human beings.

Then microcontroller will check the input coming from these two sensors and

simultaneously if somebody is present then automatically checks for the light intensity and

the temperature. And then if the room is found dark it switches ON the lights and if the

temperature is more it switches ON the fans. And if nobody is present then all the lights

will be switched off automatically.

27

Bharathi Navaneethakrishnan, NeelamegamP. FPGA-Based Temperature

Monitoring and Control System for Infant Incubator, Vol. 143, No. 8,

August 2012, pp. 88-97.

The incubator plays a key role in taking care of premature infants in hospitals.

Preterm babies who receive incubator care after birth are two to three times less likely to

suffer depression as adults. In this work, an efficient FPGA-based temperature monitoring

and control system is designed and implemented using LM35D sensor and associated

peripherals to measure and control the temperature of incubator. This paper proposed an

experimental framework and Verilog implementation of, protocol for reading temperature

by FPGA from 12-bit ADC which is connected with sensor, the control algorithm at

FPGA, passing control signals to electronic relay for controlling the temperature of the

incubator and displaying the temperature in the LCD display. The performance of the

developed system is analysed and it consumes very low power compared to conventional

system. It also shows 5 times increase in computation speed over the traditional embedded

temperature monitoring system.

Y.Nandhini, Asst.Prof. D. Muralidharan. FPGA Based 3D Motion Sensor,

Vol. 143, No. 8, August 2012, pp. 88-97.

The main objective of this paper is to explain the functioning of a device, designed

to sense the real time motion changes of an object. This motion sensing device Digital

Accelerometer can be used to sense any change in the position of an object with respect to

its original position, all along the three axes. This Digital accelerometer is to be put into its

function controlled by a Field Programmable Gate Array (FPGA). The above motion

sensing device connected with the FPGA will also be useful in reducing complexity factors

such as area consumption, cost, etc in installing the objects and at the same time, the

device could also be introduced in an easier way. This paper is mainly to deal with the

experimental procedure in detecting such changes using this motion sensing device Digital

Accelerometer.