Arduino based Thermal Flashlight using IR sensor

B.Tech, VIth semester,Electrical Engineering Department,Delhi Technological University.

ABSTRACT

Ever since the invention of thermometer, various techniques have been developed and used to measure temperature of solid, liquid and gaseous matters. But none of these techniques could measure the temperature accurately from a remote place, which sometimes becomes a necessity particularly when the object under testis in a dangerous or inaccessible area. Also, the conventional methods of measuring temperature like a mercury thermometer are not only dangerous to use, but also are hazardous to the environment. So an alternate means using modern electronics technology of measuring and sensing the temperature variations is desired. Presented here is a remote sensing infrared thermometer to measure the temperature without contact and display it on a LCD screen. The temperature of the object under test is sensed by an infrared temperature sensor (MLX90614) designed for non-contact temperature sensing, which sends the temperature value over to the microcontroller (Arduino UNO) which is then displayed in degrees Celsius at the LCD display. The sensor detects the total energy in the infrared radiation from object over a wide angle, and this energy gives the temperature of the object. The IR sensor, which is a digital sensor with its own microcontrolleron board, provides two temperature readings: A) the sensors own (body) temperature and B) the object-in-sight temperature, measured using infra-red. It can measure from -70C to 380of the object temperature. In a properly calibrated system, one can measure temperatures of the surroundings or an object up to high accuracy of 0.5 degrees. Also, a combination of RGB leds indicate the temperature ranges of the surroundings.

ACKNOWLEDGEMENT

The satisfaction and euphoria that accompany the successful completion of any task would be incomplete without the mentioning of the people whose constant guidance and encouragement made it possible. We take pleasure in presenting before you, our project, which is result of studied blend of both research and knowledge. We express our earnest gratitude to our internal guide and mentor, Assistant Professor Dr. M. M Tripathi Department of EE for his constant support, encouragement and guidance. We are grateful for his cooperation and his valuable suggestions. Also, we are thankful to those physicists and engineers who envisioned, designed and developed these tools for us to use and apply. Lastly we are thankful to the almighty god and our parents for their constant support, blessings and wishes.

MD Perwez Alam, 2K12/EE/079Mohit Jain, 2K12/EE/084Nitish Kumar, 2K12/EE/095

CERTIFICATE

This is to certify that the Project titled REMOTE SENSING THERMOMETER submitted by MD Perwez Alam, Mohit Jain & Nitish Kumar in partial fulfillment of the course work requirement for B.Tech. Program in the Department of ELECTRICAL & ELECTRONICS Engineering, DELHI TECHNOLOGICAL UNIVERSITY, has been completed by them under my guidance and supervision. This Project Report has been found quite satisfactory.

Project Mentor

Dr. M.M Tripathi Asst. Professor Department of EE Delhi Technological University

CONTENTS:1. Introduction1.1 1.2 Literature survey1.2.1 Analysis and synthesis of Remote Sensing of Environment Temperature 1.2.2 Analysis and synthesis of Remote Sensing Device1.2.3 Infrared Thermometers 2. Components2.1 Arduino Microcontroller2.2 Lcd display with potentiometer2.3 MLX90614 IR sensor2.4 Resistor, Capacitor2.5 Leds3. Project Description3.1 Introduction to the system3.2 Components used3.3 Circuit Diagram4. Results and discussion5. Conclusion.6. References7. Appendix

1.1 About the Project

Thermal flashlight is a speculative object, which enables the user to read the surface temperature of an object by pointing flashlight at it. Using this one can easily recognize the target temperature by looking at the LCDs. It expands our daily perceptions and experiences in an intuitive way. It comprises of super bright tri color LEDs, an ARDUINO, IR thermometer. This uses state of the art ARM cortex M4 processor for simple interfacing of RGB leds and concepts like display LCD, and programming the arduino.

Fig 1.1 Arduino based Thermal Flashlight1.2 LITERATURE SURVEY

1.2.1 Literature survey 1.Analysis and synthesis of Remote Sensing of Environment Temperature Department of Geography, University of Western Ontario, London, ON, Canada N6A 5C2

Date of Conference: 15 Aug 2003Author(s): J.A Voogt and T.R Oke

Volume: 86, Issue 3 Page(s):370-384Product Type: Conference Publications Abstract [1]

Thermal remote sensing has been used over urban areas to assess the urban heat island, to perform land cover classifications and as input for models of urban surface atmosphere exchange. Here, we review the use of thermal remote sensing in the study of urban climates, focusing primarily on the urban heat island effect and progress made towards answering the methodological questions posed by Roth et al. [International Journal of Remote Sensing 10 (1989) 1699]. The review demonstrates that while some progress has been made, the thermal remote sensing of urban areas has been slow to advance beyond qualitative description of thermal patterns and simple correlations. Advances in the application of thermal remote sensing to natural and agricultural surfaces suggest insight into possible methods to advance techniques and capabilities over urban areas. Improvements in the spatial and spectral resolution of current and next-generation satellite-based sensors, in more detailed surface representations of urban surfaces and in the availability of low cost, high resolution portable thermal scanners are expected to allow progress in the application of urban thermal remote sensing to the study of the climate of urban areas.

1.2.2 Literature survey 2.Analysis and synthesis of Remote Sensing DeviceCalifornia Air Resources Board, Haagen-Smit Laboratory 9528 Telstar AvenueEl Monte, CA 91734

Date of Conference: 26 Aug 2004Author(s): Tom Austin, Sierra Research, Andrew D. Burnette, Eastern Research Group, Inc. Rob Klausmeier de la Torre Consulting, Inc.ERG No: 187.00.002.001Product Type: Conference Publications Abstract [2]This report is intended to fulfil one objective of the Pilot Remote Sensing Study, specifically, to provide an organized synthesis and critical assessment of previous and current studies on relevant remote sensing programs. The information obtained from this task would be used to define research gaps, establish the need for further studies, and resolve controversies, if any. If possible, research gaps, controversies, etc. would be resolved by performing the rest of the Pilot Remote Sensing Study.Remote sensing measurements can be used to identify some of the vehicles with excessive tailpipe emissions that should receive a Smog Check in the near future. Since whether a vehicle can be classified as a high emitter or not depends upon the standards it was designed to meet, a high emitter manufactured recently may actually emit much less than an older high emitter. Below certain emission levels, RSDs ability to distinguish between a normal emitter and a high emitter is greatly diminished, so newer vehicles may be difficult for RSD to identify as being high emitters.

1.2.3 Literature survey 3Infrared Thermometers HEALTH TECHNOLOGY ASSESSMENT SECTION, MEDICAL DEVELOPMENT DIVISION, MINISTRY OF HEALTH MALAYSIA012/2012Prepared byMadam Sin Lian ThyeDr. Junainah Sabirin

Abstract: [3]Evaluation of body temperature is one of the oldest known diagnostic methods and is still an important sign of health and disease, both in everyday life and in medical care. Accurate Temperature measurement is critically important, particularly in neonates and immune compromised children whom suspicion of infection could result in investigations, treatment and even hospitalization. Consequently, inaccurate temperature measurement may result in Patients remain undiagnosed and untreated, or receiving unnecessary or inappropriate intervention. In health centres and hospitals, nurses are responsible for measuring body temperature accurately and it is important to take into account the kind of thermometer and the sites of the body used for taking the measurement Mercury in glass thermometer was the traditional type of thermometer used to measure body temperature. However, mercury thermometers are gradually being phased out. This is because of concerns regarding the Toxic environmental effect of mercury, namely toxicity from the absorption due to breakage and risk of infection. In recent years, infrared thermometers have been more frequently used. This type of thermometer determines the temperature of infrared emission from a source rather than absorbing heat from the tissue and reaching thermal equilibrium with it. Temperatures can typically be obtained in less than five seconds. Most thermometers of this type measure temperature at the ear drum (infrared tympanic thermometers)

Chapter 2. COMPONENTS

2.1 ARDUINO UNO

The Arduino Uno is a microcontroller board based on theATmega328(datasheet). It has 14 digital input/output pins (of which 6 can be used as PWM outputs), 6 analog inputs, a 16MHzceramic resonator, a USB connection, a power jack, an ICSP header, and a reset button. It contains everything needed to support the microcontroller; simply connect it to a computer with a USB cable or power it with an AC-to-DC adapter or battery to get started.The Uno differs from all preceding boards in that it does not use the FTDI USB-to-serial driver chip. Instead, it features theAtmega16U2(Atmega8U2up to version R2) programmed as a USB-to-serial converter.Arduinois a family ofsingle-board microcontrollers, intended to make it easier to build interactive objects or environments. The hardware consists of anopen-source hardwareboard designed around an 8-bitAtmelAVRmicrocontroller or a 32-bit AtmelARM. Current models feature aUSBinterface together with six analog input pins and 14 digital I/O pins that can accommodate various extension boards."Uno" means one in Italian and is named to mark the upcoming release of Arduino 1.0. The Uno and version 1.0 will be the reference versions of Arduino, moving forward. The Uno is the latest in a series of USB Arduino boards, and the reference model for the Arduino platform; for a comparison with previous versions, see theindex of Arduino boards.

The Uno board has a resistor pulling the 8U2 HWB line to ground, making it easier to put intoDFU mode.1.0 pinout: added SDA and SCL pins that are near to the AREF pin and two other new pins placed near to the RESET pin, the IOREF that allow the shields to adapt to the voltage provided from the board. In future, shields will be compatible with both the board that uses the AVR, which operates with 5V and with the Arduino Due that operates with 3.3V.

The specialty of using Arduino as a microcontroller is its open source hardware and digital and analog pins provided with PWM operation. The software is easy to use with a vast library of predefined functions. An Arduino's microcontroller is also pre-programmed with aboot loader that simplifies uploading of programs to the on-chipflash memory, compared with other devices that typically need an external programmer. This makes using an Arduino more straightforward by allowing the use of an ordinary computer as the programmer.SummaryMicrocontrollerATmega328

Operating Voltage5V

Input Voltage (recommended)7-12V

Input Voltage (limits)6-20V

Digital I/O Pins14 (of which 6 provide PWM output)

Analog Input Pins6

DC Current per I/O Pin40 mA

DC Current for 3.3V Pin50 mA

Flash Memory32 KB (ATmega328) of which 0.5 KB used by bootloader

SRAM2 KB (ATmega328)

EEPROM1 KB (ATmega328)

Clock Speed16MHz

Table 2.1: Operating Characteristics of Arduino Uno

Fig. 2.1.1 Interfacing of arduino with lcd screen.

2.2 LCDLiquid Crystal Display, LCDs are now commonly used as display devices. The alphanumeric LCD display with a simple interface that could be connected to a general purpose microcontroller or microprocessor, comes in variety of formats, like 16X2, 20X4 etc., based on their screen characteristics.

LCD displays utilize two sheets of polarizing material with a liquid crystal solution between them. An electric current passed through the liquid causes the crystals to align so that light cannot pass through them. Each crystal, therefore, is like a shutter, either allowing light to pass through or blocking the light.MonochromeLCD images usually appear as blue or dark gray images on top of a grayish-whitebackground. Color LCD displays use two basic techniques for producing color:Passive matrixis the less expensive of the two technologies. The other technology, calledthin film transistor(TFT) oractive-matrix, produces color images that are as sharp as traditionalCRTdisplays, but the technology is expensive. Recent passive-matrix displays using newCSTNandDSTN technologies produce sharp colors rivaling active-matrix displays.

Character LCDs, like the one used here, use a standard 16 contact interface, commonly using pins or card edge connections on 0.1inch / 2.54mm centers. Those without backlights may have only 14 pins, omitting the final two pins powering the light.

Fig. 3.

2.1 Amber backlight on a LCD display

The pin out for a 16 pin 16X2 LCD display is as follows:1. Ground2. VCC (+3.3 to +5V)3. Contrast adjustment (VO)4. Register Select (RS). RS=0: Command, RS=1: Data5. Read/Write (R/W). R/W=0: Write, R/W=1: Read (This pin is optional due to the fact that most of the time you will only want to write to it and not read. Therefore, in general use, this pin will be permanently connected directly to ground.)6. Clock (Enable). Falling edge triggered7. Bit 0 (Not used in 4-bit operation)8. Bit 1 (Not used in 4-bit operation)9. Bit 2 (Not used in 4-bit operation)10. Bit 3 (Not used in 4-bit operation)11. Bit 412. Bit 513. Bit 614. Bit 715. Backlight Anode (+) (If applicable)16. Backlight Cathode (-) (If applicable)The nominal operating voltage for LED backlights is 5V at full brightness, with dimming at lower voltages dependent on the details such as LED color. Non-LED backlights often require higher voltages.The Data pins are connected to the digital pins of the Arduino for output signals. Also,register select and enable pins are connected to the microcontroller. COntrastadjustment is done using a potentiometer connected to the LCD. Backlight anode and cathodepins provide the backlight options. The read/write pin is generally grounded as in the system, the display is only used for write options.

Display LCD using Arduino.

LiquidCrystal- display() and noDisplay()TheLiquid Crystal Libraryin Arduino uno allows to control LCD displays that are compatible with the HitachiHD44780driver. This example sketch shows how to use the display() and noDisplay() methods to turn on and off the display. The text to be displayed will still be preserved when you use noDisplay() so it's a quick way to blank the display without losing everything on it.Hardware Required Arduino Board LCD Screen (compatible with HitachiHD44780driver) pin headers to solder to the LCD display pins 10k Potentiometer breadboard hook-up wireCircuitBefore wiring the LCD screen to your Arduino we suggest to solder a pin header strip to the 14 (or 16) pin count connector of the LCD screen, as you can see in the image above.To wire your LCD screen to your Arduino, connect the following pins: LCD RS pin to digital pin 12 LCD Enable pin to digital pin 11 LCD D4 pin to digital pin 5 LCD D5 pin to digital pin 4 LCD D6 pin to digital pin 3 LCD D7 pin to digital pin 2Additionally, wire a 10K pot to +5V and GND, with it's wiper (output) to LCD screen's VO pin (pin3).The display in a Lcd screen and its contrast is controlled by using a potentiometer which controls the voltage input to the display, which is explained in the following text.

2.2.2 POTENTIOMETERApotentiometer, informally apot, is a three-terminalresistorwith a sliding or rotating contact that forms an adjustablevoltage divider.If only two terminals are used, one end and the wiper, it acts as avariable resistororrheostat.Apotentiometer measuring instrumentis essentially a voltage divider used for measuringelectric potential(voltage); the component is an implementation of the same principle, hence its name.Potentiometers are commonly used to control electrical devices such as volume controls on audio equipment. Potentiometers operated by a mechanism can be used as positiontransducers, for example, in ajoystick. Potentiometers are rarely used to directly control significant power (more than awatt), since the power dissipated in the potentiometer would be comparable to the power in the controlled load.Here in the system, potentiometer is used to control the voltage to the lcd display so as to control the Contrast of the font displayed. Turning the potentiometer increases/decreases the voltage and hence the contrast.

Fig.2.2.2 LCD connected through the potentiometer to the microcontroller.

PIN DIAGRAM OF THE CONTROLLER.

F

Fig. 2.2.3 Pin Diagram of the Controller

2.3 MLX90614 IR SENSOR

MLX90614 I2C Infrared ThermometerTheMelexis MLX90614is an infrared thermometer designed for non-contact temperature sensing. It contains an internal 17-bit ADC and a custom DSP chip to achieve high accuracy and resolution. It has an I2C or PWM interface and will operate off of 3.3V. IR thermometers measure the IR surface temperature of an object. The distance to the object does not change the temperature reading as long as the object fills the sensors field of view (beam width). IR temperature readings can vary depending on theemissivityof the target. Metals such as aluminum have low emissivity and will tend to read lower IR temperatures. Calculations to compensate the temperature for lower emissivity can be used, if you know the emissivity of the surface you are measuring.

Fig 2.3.1 IR sensor MLX90614There are quite a number of different version of this device with voltages of 5 or 3V, beam width ranging from 90 to 5 degrees, accuracy ratings from .5 C to .1 C, and update rates ranging from .1 to 1.3 seconds. The narrow beam width devices cost more. The application noteUnderstanding MLX90614 on-chip digital signal filtersexplains the tradeoffs in accuracy and update rates using the on-chip DSP filters. One of the more interesting and expensive ones (about the price of an mbed) with a narrow five degree beam width or field of view (FOV) is shown below.

It is also available on some older breakout boards and evaluation boards, but the sensor can be directly interfaced to mbed. The wire leads are a bit problematic for a breadboard. They would need to be bent quite a bit to fit and that is probably not the best idea on an expensive sensor. A socket could be used for the 4-pin TO-39 case if one was available on a breakout board. One easy solution is to use four M/F stranded breadboard jumper wires like the ones shown below fromSparkfun. The sensor leads are a bit too small for the jumper, but after assembly a light crimp at the opening where the silver socket pin shows through the black jumper cover with needle nose pliers works well to hold it firmly in place. This also allows for movement of the sensor and is handy if it is ever mounted on a servo.

Fig 2.3.2 M/F jumper wires can be used to attach the sensor to a breadboard.

WiringMbedMLX90614Pullups

GndVSS - gnd

VoutVDD - 3.3V

p27SCL - I2C clock4.7K

p28SDA - I2C data4.7K

Table 2.3 Pinouts of the IR sensor Fig.2.3.3 the 4 pins

2.4.1 RESISTOR IntroductionA resistor is a passive two-terminal electrical component that implements electrical resistance as a circuit element

Fig.2.4.1 Resistors

The current through a resistor is in direct proportion to the voltage across the resistor's terminals. This relationship is represented by Ohm's law: (EQN 1)Where I is the current through the conductor in units of amperes, V is the potential difference measured across the conductor in units of volts, and R is the resistance of the conductor in units of ohms. The ratio of the voltage applied across a resistor's terminals to the intensity of current in the circuit is called its resistance, and this can be assumed to be a constant (independent of the voltage) for ordinary resistors working within their ratings.Practical resistors have a series inductance and a small parallel capacitance; these specifications can be important in high-frequency applications. In a low-noise amplifier or pre-amp, the noise characteristics of a resistor may be an issue. The unwanted inductance, excess noise, and temperature coefficient are mainly dependent on the technology used in manufacturing the resistor.

Fig.2.4.2 Electronic Symbols

Series and parallel resistorsIn a series configuration, the current through all of the resistors is the same, but the voltage across each resistor will be in proportion to its resistance. The potential difference (voltage) seen across the network is the sum of those voltages, thus the total resistance can be found as the sum of those resistances:

(EQN 2)Resistors in a parallel configuration are each subject to the same potential difference (voltage), however the currents through them add. (EQN 3)

Resistor color coding Fig.2.4.3 Resistor color codingTo distinguish left from right there is a gap between the C and D bands. Band A is first significant figure of component value (left side) Band B is the second significant figure Band C is the decimal multiplier Band D if present, indicates tolerance of value in percent (no band means 20%)

For example, a resistor with bands of yellow, violet, red, and gold will have first digit 4 (yellow in table below), second digit 7 (violet), followed by 2 (red) zeros: 4,700 ohms. Gold signifies that the tolerance is 5%, so the real resistance could lie anywhere between 4,465 and 4,935 ohms.The Standard Resistor Color Code Table 1 Standard Resistor Color Code 2.4.2 CAPACITOR

IntroductionA capacitor (originally known as condenser) is a passive two-terminal electrical component used to store energy in an electric field. The forms of practical capacitors vary widely, but all contain at least two electrical conductors separated by a dielectric (insulator); for example, one common construction consists of metal foils separated by a thin layer of insulating film. Capacitors are widely used as parts of electrical circuits in many common electrical devices.

Fig.2.4.4 Capacitors

Features: ceramic disc capacitor Linear temperature coefficient of capacitance. High Stability of capacitance. Low loss at wide range of frequency.Specification Operating temp. range -25 to +85 degree centigrade. Rated working voltage DC 50V, 500v. Test Voltage 3 times of the rated voltage. Capacitance within the tolerance and Q-Factor at 1 Mhz, 1+- 0.2 Vrms.25 degree centigrade.

When there is a potential difference (voltage) across the conductors, a static electric field develops across the dielectric, causing positive charge to collect on one plate and negative charge on the other plate. Energy is stored in the electrostatic field. An ideal capacitor is characterized by a single constant value, capacitance, measured in farads. This is the ratio of the electric charge on each conductor to the potential difference between them. The capacitance is greatest when there is a narrow separation between large areas of conductor, hence capacitor conductors are often called "plates," referring to an early means of construction. In practice, the dielectric between the plates passes a small amount of leakage current and also has an electric field strength limit, resulting in a breakdown voltage, while the conductors and leads introduce an undesired inductance and resistance.

Fig. 2.4.5 Varieties of CapacitorsPractical capacitors are available commercially in many different forms. The type of internal dielectric, the structure of the plates and the device packaging all strongly affect the characteristics of the capacitor, and its applications.Capacitors are widely used in electronic circuits for blocking direct current while allowing alternating current to pass, in filter networks, for smoothing the output of power supplies, in the resonant circuits that tune radios to particular frequencies, in electric power transmission systems for stabilizing voltage and power flow, and for many other purposes.

Theory of operationA capacitor consists of two conductors separated by a non-conductive region. The non-conductive region is called the dielectric. In simpler terms, the dielectric is just an electrical insulator. Examples of dielectric media are glass, air, paper, vacuum, and even a semiconductor depletion region chemically identical to the conductors.

Fig. 2.4.6 Theory of operation of capacitor

A capacitor is assumed to be self-contained and isolated, with no net electric charge and no influence from any external electric field. The conductors thus hold equal and opposite charges on their facing surfaces, and the dielectric develops an electric field. In SI units, a capacitance of one farad means that one coulomb of charge on each conductor causes a voltage of one volt across the device.The capacitor is a reasonably general model for electric fields within electric circuits. An ideal capacitor is wholly characterized by a constant capacitance C, defined as the ratio of charge Q on each conductor to the voltage V between them. (EQN 4)Sometimes charge build-up affects the capacitor mechanically, causing its capacitance to vary. In this case, capacitance is defined in terms of incremental changes: (EQN 5)

2.5 LED (LIGHT EMITTING DIODE)Introduction

Fig.2.5.1 Light Emitting Diode

A light-emitting diode (LED) is a semiconductor light source. LEDs are used as indicator lamps in many devices and are increasingly used for other lighting. Appearing as practical electronic components in 1962, early LEDs emitted low-intensity red light, but modern versions are available across the visible, ultraviolet, and infrared wavelengths, with very high brightness.

Internal Description of LEDWhen a light-emitting diode is forward-biased (switched on), electrons are able to recombine with electron holes within the device, releasing energy in the form of photons. This effect is called electroluminescence and the color of the light (corresponding to the energy of the photon) is determined by the energy gap of the semiconductor. An LED is often small in area (less than 1 mm2), and integrated optical components may be used to shape its radiation pattern.

Fig.2.5.2 Internal description of LED

LEDs present many advantages over incandescent light sources including lower energy consumption, longer lifetime, improved physical robustness, smaller size, and faster switching. LEDs powerful enough for room lighting are relatively expensive and require more precise current and heat management than compact fluorescent lamp sources of comparable output.

Fig.2.5.3 Electronic Symbol of LED

Light-emitting diodes are used in applications as diverse as aviation lighting, automotive lighting, advertising, general lighting, and traffic signals. LEDs have allowed new text, video displays, and sensors to be developed, while their high switching rates are also useful in really beadvanced communications technology. Infrared LEDs are also used in the remote control units of many commercial products including televisions, DVD players, and other domestic appliances.

Advantages of using LEDs

LEDs produce more light per watt. Than do incandescent bulbs; this is useful in battery powered or Energy saving device. LEDs can emit light of an intended color without the use of colour filters that traditional lighting methods require. This is more efficient and can lower initial costs. LEDs are Ideal for use in applications that are subject to frequent on-off cycling, unlike fluorescent lamps that burn out more quickly when cycled frequently, or HID lamps that require a long time before restarting. LEDs being solid state components, are difficult to damage with external shock. Fluorescent and incandescent bulbs are easily broken if dropped on the ground. LEDs have extremely long life span. One manufacturer has calculated the ETTF (Estimated Time To Failure) for their LEDs to be between 100,000 and 1,000,000 hours. Fluorescent tubes typically are rated at about 30,000 hours, and incandescent light bulbs at 1,000- 2,000 hours.

3. PROJECT DESCRIPTION

3.1 IntroductionThe temperature of the object under test is sensed by a temperature sensor MLX90614 which is an infrared non-contact temperature sensor.A 5V dc supply is used to operate the IR sensor as well as the microcontroller. The IR sensor has two parts integrated inside it, the IR sensitive thermopile detector chip and the signal conditioning ASIC. A low noise amplifier and a 17 bit ADC and powerful DSP units enable high accuracy and resolution of the thermometer. The thermometer comes calibrated digital SMBus output giving full access to the measured temperature in the complete temperature range(s) with a resolution of 0.02C.The user can configure the digital output to be PWM. As a standard, the 10-bit PWM is configured to continuously transmit the measured temperature in range of -20 to 120 C, with an output resolution of 0.14 C.

3.1.1 SYSTEM DESCRIPTIONThe connections are made as shown in fig 3.1. Analog input pins (A4, A5) of the microcontroller are connected to the IR sensor pins (SLC, SDA) using jumper cables. The sensor senses the temperature within its infrared beam and through a 17 pin internal ADC, gives the analog input to the Arduino. Resistors of 4.7K ohms is connected between the SLC, SDA and power supply pins. Also a capacitor is connected by the supply and pin Vcc to provide ripple free DC for optimum usage of the sensor. The sensor is grounded and gets it power supply of 3.3V from the power pins of the Board, through the pins Vcc and Vss. The same power is provided to the leds, by the means of creating a power base in the breadboard, who are connected by the PWM digital pins (D9,10,11) of the arduino. They are coded to change color and display as per the temperature range of the object under test. This combination of 3 leds provide the thermal flashlight operation, where the green led lights from temperature on or below 23 degrees Celsius, the blue led lights above this range. The red led lights for temperature above 8 degrees. The Led combination is connected to the power supply in a common anode formation, with suitable resistors applied for current limitation and varying the intensity. Since the leds are connected by PWM, the transition is a smooth one when they change color from one temperature range to other. Also, the sensor being a non-contact one, is based on infrared sensing and hence dependent on emissivity properties of the objects. The second part of the system composes of a 16X2 Lcd display which gives the current temperature in a digital form up to 2nd decimal place. The lcd screen gets the input from the digital pins (D3-6) of the microcontroller and gets Dc power 5V. The display is backlight by providing power to the last 2 pins of the 16 pin display. Data pins (D4-7) are connected to the arduino which provide it with the temperature signal. The contrast of the display is controlled by the 3 pin potentiometer, connected to the CNT pin of the display. Enable and select pins are connected to the microcontroller as its interfacing. Since it is used just for display option, R/W is permanently grounded.

3.2 Component used:

TEMPERATURE SENSOR-MLX90614 16*2 LCD 16 pins Arduino Uno Microcontroller 10K POTENTIOMETRE BREADBOARD LED- red green blue Resistors : for limiting the current to the devices. R1 4.7-kilo-ohm R2 -4.7-kilo-ohm R3 - 220 -ohm R4 - 100-ohm R5- 47-ohm

Capacitors: 0.01F for providing ripple free pure dc input.

3.3 CIRCUIT DIAGRAM

Fig 3.1 Circuit diagram of the system

4. RESULTS AND DISCUSSIONS

The system proposed deals with problems faced in remote sensing of temperatures. The system has an IR sensor which directly reads temperatures of objects without contact. The IR sensor is connected to the microcontroller Arduino UNO, which stores the value of the temperature and sends it to the LCD screen for display. This is a real time model which gives the temperature of surroundings or objects instantaneously. The temperature readings can be stored and later plotted for studying its variations and analysis.It has wide applications starting from medical appliances where an IR sensor based thermometer can gradually phase out the mercury based one, providing better and accurate body temperature readings. It can be used in climatology as the surface temperature is of prime importance to the study of urban climatology. It modulates the air temperature of the lowest layers of the urban atmosphere, is central to the energy balance of the surface, helps to determine the internal climates of buildings and affects the energy exchanges that affect the comfort of city dwellers. Also, another major application is in remote sensing of temperature. This project can measure the temperature in industries where human cannot reach. This project could monitor the temperature from remote area and show the temperature at receiver side in the form of voltage, with the help of calibration between temperature and voltage. We can measure the temperature of the machine in industries at critical area where temperature of machine is not measured directly. This could be used for temperature control of systems in general and motor drives in particular. Hence we have achieved through this model, detecting temperatures through IR sensor and taking cognizance of this fact, it can be further developed for many of the above mentioned applications, particularly for remote sensing and thermal imaging. Through thermal imaging, one can sense points of heat leakage in plants or have a have a thermally varying contour of a region. Also, using the matlab applications of the microcontroller, we can have the temperature variations of an object over a period of time and can use the plots for analysis.

5. CONCLUSION

Ever since the invention of thermometer, various techniques have been developed and used to measure temperature of solid, liquid and gaseous matters. But none of these techniques could measure the temperature from a remote place, which sometimes becomes a necessity, particularly when the object under test is in a dangerous or inaccessible area. Presented here is a remote sensing thermometer to measure the temperature from a remote place.

The main scope of this project was to measure the temperature in industries where human cannot reach. This project has monitored the temperature from remote area and shown the temperature at receiver side in the form of voltage, with the help of calibration between temperature and voltage. We measure the temperature of the machine in industries at critical area where temperature of machine is not measured directly.

This project, on further development can be used extensively in different fields, ranging from motor drives to medical applications. The main advantage of using an infrared sensor is its remote sensing capability of an object not within contact with high accuracy. Infrared tympanic thermometers would measure body temperature detect infrared energy emanating from the ear canal and tympanic membrane, hence not prune to the harmful effects of a traditional thermometer.Also, surface temperatures and thermal imaging applications can be made using such a device.

6. REFERENCESLiterature surveys:[1]: Author J.A. Voogt and T.R Oke titled Analysis and synthesis of remote sensing Vol: 86, Issue 3, pages-370-384[2]:Author Tom Austin, Sierra Research titled Analysis of remote sensing devices Erg No. 187.00.002.001, Conference Publication[3]:Author Madam Sin Lian titled Infrared Thermometers

Arduino code:http://bildr.org/2011/02/mlx90614-arduino/ For i2c library and instructionshttp://publiclaboratory.org/tool/thermal-camerahttp://splinter.com.au/blog/?p=29http://www.kasperkamperman.com/blog/arduino/arduino-programming-hsb-to-rgb/

MLX90614 specs: Data sheetMLX90614 family Single and Dual Zone Infra Red Thermometer in TO-39 Data sheet

LCD display: http://arduino.cc/en/Tutorial/LiquidCrystalDisplay

Articles referred: Author JM Kornflied, RR Reagen titled Flashlight Patent D566,309,208http://public laboratory.org/tool/thermal-camera/

7. APPENDIXThe code in the microcontroller for operating the leds(thermal flashlight) and displaying the current temperature on the lcd display as per the input given to the analog pins by sensor is as follows:#include #include #include "Wire.h"//#include "BlinkM_funcs.h" const float lowReading = 60;const float highReading = 75;const unsigned char separatorCharacter = 255;LiquidCrystal lcd(12, 13, 5, 4, 3, 2); void setup(){ pinMode(9,OUTPUT); pinMode(10,OUTPUT); pinMode(11,OUTPUT); lcd.begin(16, 2); lcd.setCursor(0, 1); lcd.clear(); i2c_init(); //Initialise the i2c bus PORTC = (1