CHAPTER 2 Theory related to project 2
Theory related to project
In this chapter we will discuss about the hardware that are use in that project.
Raspberry pi 3
IR infrared cameras extend from the simplest point-shoot-detect infrared cameras to advanced infrared cameras for detailed inspections. An infrared camera is a non-contact device that detects infrared energy (heat) and converts it into an electronic signal, which is then processed to produce a thermal image on a video monitor and perform temperature calculations. Heat sensed by an infrared camera can be very precisely quantified, or measured, allowing you to not only monitor thermal performance, but also identify and evaluate the relative severity of heat-related problem. Shown in (fig 1.2)
usually speaking the higher an things temperature, the more infrared rays is emitted as black body radiation. A special camera can detect this rays in a way similar to the way an ordinary camera detect visible light. It works even in night because ambient light level does not matter. This makes it useful for rescue operations in smoke filled road.
A main difference with optical cameras is that the focusing lenses cannot be made of glass as glass blocks long wave infrared light. particular materials such as Germanium or Sapphire crystals have to be used. Germanium lenses are also quite breakable, so often have a hard coating to care for against accidental contact. The higher cost of these special lenses is one reason why thermo graphic cameras are more expensive.
Images from infrared cameras tend to be colorless because the cameras generally use an image sensor that does not distinguish different wave lengths of infrared radiation. Color image sensors require a multipart construction to distinguish wavelengths, and color has less meaning outside of the normal visible range because the differing wave lengths do not map regularly into the system of color vision used.
Sometimes these color less images are displayed in pseudo color, where changes in color are used rather than changes in strength to display changes in the signal. This technique called density slicing, is useful because although humans have much greater active range in intensity recognition than color overall, the ability to see fine intensity differences in clear areas is fairly limited.
For use in temperature measurement the brightest (warmest) parts of the image are customarily colored white, intermediate temperatures reds and yellows, and the dimmest (coolest) parts black. A scale should be shown next to a false color image to relate colors to temperatures. Their resolution is considerably lower than that of optical cameras, mostly only 160 x 120 or 320 x 240 pixels, although more expensive cameras can achieve a resolution of 1280 x 1024 pixels. Thermo graphic cameras are much more expensive than their visible-spectrum counterparts, though low-performance add-on thermal cameras for smart phones became available for hundreds of dollars in 2014. Higher-end models are often deemed as dual-use and export-restricted, particularly if the resolution is 640 x 480 or greater, unless the refresh rate is 9 Hz or less. The export of thermal cameras is regulated by International Traffic in Arms Regulations.
In 1929, Hungarian physicist kalman tihanyi invented the infrared-sensitive (night vision) electronic television camera for anti-aircraft defense in Britain.8
The first thermographic cameras developed were infrared line scanners. This was created by the US military and Texas Instruments in 1947 and took one hour to produce a single image. While several approaches were investigated to improve the speed and accuracy of the technology, one of the most crucial factors dealt with scanning an image, which the AGA company was able to commercialize using a cooled photoconductor.
The first infrared lines can system was the British Yellow Duckling of the mid-1950s.9
This used a continuously rotating mirror and detector, with Y axis scanning by the motion of the carrier aircraft. Although unsuccessful in its intended application of submarine tracking by wake detection, it was applied to land-based surveillance and became the foundation of military IR lines can.
This work was further developed at the Royal Signals and Radar Establishment in the UK when they discovered mercury cadmium telluride could be used as a conductor that required much less cooling. Honeywell in the United States also developed arrays of detectors which could cool at a lower temperature, but they scanned mechanically. This method had several disadvantages which could be overcome using an electronic scanning system. In 1969 Michael Francis Tompsett at English Electric Valve Company in the UK patented a camera which scanned pyro-electronically and which reached a high level of performance after several other breakthroughs throughout the 1970s. Tompsett also proposed an idea for solid-state thermal-imaging arrays, which eventually led to modern hybridized single-crystal-slice imaging devices. For example, firefighters use it to see through smoke, find people, and localize hotspots of fires.
Camera: 5 million pixels
Photosensitive module: OV5647
CCD size: ¼ inches
Focal length: 3.6MM (adjustable)
Diagonal: 75.7 degrees
Sensor best PIX: 1080p
4 screw holes
Can be used in a fixed position
3.3v external power supply
Support access to the infrared lights or fill light
Dimension: 25mm x 24mm (0.98″ x 0.94″)
We know-how IR light every time we feel the heat of the sun on our skin or the warmth of a camp fire. Technically, what we are experiencing in these instances is thermal infrared light. Scientists call waves of electromagnetic energy that travel through space light. We tend to think of light as only the radiant energy that we see with our eyes. But the light we can detect with our eyes is a very tiny fraction of all the types of light that exist. Infrared light is one type of light that is invisible to us. Gamma rays, X-rays, ultraviolet light, microwaves and radio waves are other types of invisible light. All of these rays and waves are the same type of electromagnetic energy. They are different only because the lengths of their waves are different.
When we see something by visible light, our eyes allow us to distinguish the light of different waves as different colors. The waves that are short are blue and the waves that are long appear as red. We can’t really see the waves; we only see the colors that our mind creates to help us interpret the world. Every color has a distinct wavelength. For example, violet light can be seen at light wavelengths of around 0.4 micron (*) and yellow light is made up of waves that are 0.6 microns long. Reddish colors begin at wavelengths of about 0.65 microns. Your eyes cannot see light that has a wavelength longer than 0.7 microns. Shown in (fig 1.3)
What is infrared?
Infrared radiation is a type of electromagnetic radiation, as are radio waves, ultraviolet radiation, X-rays and microwaves. Infrared (IR) light is the part of the EM spectrum that people encounter most in everyday life, although much of it goes unnoticed. It is invisible to human eyes, but people can feel it as heat.
IR radiation is one of the three ways heat is transferred from one place to another, the other two being convection and conduction. Everything with a temperature above about 5 degrees Kelvin (minus 450 degrees Fahrenheit or minus 268 degrees Celsius) emits IR radiation. The sun gives off half of its total energy as IR, and much of its visible light is absorbed and re-emitted as IR, according to the University of Tennessee.
According to the Environmental Protection Agency, incandescent bulbs convert only about 10 percent of their electrical energy input into visible light energy; about 90 percent is converted to infrared radiation. Household appliances such heat lamps and toasters use IR radiation to transmit heat, as do industrial heaters such as those used for drying and curing materials. These appliances generally emit blackbody radiation with a peak energy output below the wavelength of visible, though some energy is emitted as visible red light.
A TV remote control uses IR waves to change channels. In the remote, an IR light-emitting diode (LED) or laser sends out binary coded signals as rapid on/off pulses, according to NASA. A detector in the TV converts these light pulses to electrical signals that instruct a microprocessor to change the channel, adjust the volume or perform other actions. IR lasers can be used for point-to-point communications over distances of a few hundred meters or yards.
A thin-film-transistor liquid-crystal display (TFT LCD) is a variant of a liquid-crystal display (LCD) that uses thin-film-transistor (TFT) technology to improve image qualities such as addressability and contrast. A TFT LCD is an active-matrix LCD, in contrast to passive-matrix LCDs or simple, direct-driven LCDs with a few segments.
TFT LCDs are also used in car instrument clusters because they allow the driver to customize the cluster, as well as being able to provide a skeuomorphic, analog-like display with digital elements. This 7″ Raspberry Pi LCD provides you with the ability to create a standalone device that can be utilized as a custom tablet or an all-in-one interactive interface for a future project using your Raspberry Pi 3. Each LCD features a full color 800 x 480 capacitive that connects to the Pi via an included adapter board which handles all of your power and signal conversion needs. An updated version of Raspbian OS on the A+, B+ and Pi2B is required for the display to work (the display does not work with the current version of Raspbian available on the Model A or B).
What makes this LCD great is the fact that it only requires two connections to be hooked up to the Pi; power from the Pi’s GPIO port and a ribbon cable that connects to the DSI port present on all Raspberry Pi’s. With this Raspberry Pi LCD you can create your own ‘Internet of Things’ (IoT) devices including a visual display by simply connecting your Pi, developing a easy Python script to interact with the display, and you’ll be ready to create your own home automation devices with touch screen capability. Shown in (fig 1.4)
2.4.1 KEY FEATURES
7 inches TFT LCD Screen IPS Display
Supports Raspberry Pi, Orange Pi, banana Pi, Beagle Bone Black as well
can be used individually as well
1024 x 600 (Pixel), IPS screen; Full view
Compatible with Raspberry Pi 3 Model B/ 2B/ B+ (Provide full image or separate driver)
For Raspberry Pi, you can run Raspbian and Ubuntu(only provide the image for Pi 3B/2B)
Compatible with Beagle Bone Black and Banana Pi/Pro;(Provide a full image)
USB and HDMI display don’t occupy any GPIO
2.5Raspberry pi 3
This is an introduction of Raspberry Pi 3 Model B. We will explore what Raspberry Pi 3 has to offer in terms of its features and performance. I would like to introduce Raspberry Pi as a world’s most inexpensive and powerful Single Board Computer. Ever since the launch of Raspberry Pi from 2012, we have seen several version of it. This is world’s cheapest microprocessor unit specially built for learner and makers. We can easily learn how software and hardware work together without been worrying about damage/cost. Raspberry Pi has a huge community and plenty of online resources which make learning smooth. Raspberry Pi is a card-sized minicomputer that can either operate on mains or battery power. Raspbian is a provided operating system (OS), but there are various other ARM-Linux OS variants that can run on it. This miniature device can be used for robotics, arcade machines, and temperature probing devices. It can also be used for MATLAB applications, among others, and comes in a variety of models with different interfaces for different requirements. Raspberry Pi 2 Model B (the latest version of the hardware as of November 2015) has 1 gigabyte (GB) of random access memory (RAM), a 900MHz quad-core ARM processor, four universal serial bus (USB) interfaces, an Ethernet port, a mini USB for power supply and high-definition multimedia interface (HDMI) for display. The OS is flashed onto a micro Secure Digital (SD) card 4.
The running device can either be accessed directly using a USB keyboard, mouse and display or via a LAN port by creating a secure shell (SSH) session remotely. Shown in (fig 1.5)
Previous related works
Table 1. Review of Previous Published Articles
Agrawal & Singhal 5 Research discussed a smart drip irrigation system using Raspberry pi including a proposed design for a home automation system, energy efficient devices, including raspberry pi, Arduino microcontrollers, Xbee modules and relay boards.
These energy efficient devices were used due to low cost.
Danymol, Ajitha &
Gandhiraj 6 Researchers explained about real time communication systems and the use of Raspberry Pi because it is cheap and small
Fung, White, Jouet,
Singer & Pezaros 7 Researchers discussed Glasgow Raspberry Pi cloud and Pi cloud for resource management include computing.
Table 2. Server Operating System
Server Operating System
Operating system Version Open source costs
Ubuntu linux 14.02.2 LTS yes O$
Noobs 2.8.2 yes 0$
Turnkey Linux 13.0 Yes 0$
HDMI stands for High Definition Multimedia Interface and is the most frequently used HD signal for transferring both high definition video and audio over a single cable.
HDMI is used both in the commercial AV sector and is the most used cable in homes connecting devices such as digital TV, DVD player, BluRay player, Xbox, Play station and Apple TV with the television.
More and more home AV devices are being connected using this simple, effective cable, but now HDMI is also featuring on laptops and PCs and therefore becoming the standard for the corporate and commercial markets – for education, presentation, digital signage and retail display .shown in (fig 1.6)
Fig 1.6::HDMI cable
We need 12volt 2amp power supply to run the device. shown in (fig 1.7)
Input: worldwide 100V ~ 240V 50/60Hz; Output: 12V 2A (2000mA) (Converts from 100V -240V AC all outlet into a 12V DC plug)
Reliable Power Adapter: UL listed, FCC certified, over current/short circuit protection
12V 2A(2000mA) DC Power Jack Adapter: connector size 5.5 x 2.1mm, center: positive; 3.9 feet cord with Velcro fastener for convenient use and easy storage
Male DC Power Jack Connector: features screw terminal which can connect to the lead wire of single color LED strip lights directly
Wide Range Uses: perfectly be used to power router, switch, CCTV camera, networking HUB, electric toys, router, breast pumps,
LED string light, Yamaha keyboard, Polycom Sound Point telephones
For switch, CCTV camera, networking hub, security cameras, IP cameras, audio and video devices, digital media, hard drives,
computer peripherals, amplifiers, satellite radio receivers etc. It works with devices that require 12V 2A DC power and physically fit the plug.