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nents of Embedded Systems., lication Specific :, 5.1 Washing Machine ., , 2 Microwave Owen oy, © Embedded System (AES), Area Network (CAN), Local Interconnect Network (LIN)., ‘cuit Board (PCB)
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P's, , , , Embedded System (8 VF G1-7,) (ey, ae, [8.1 INTRODUGT ON, , ‘ An embedded ayster je typically a lees powerfiil eampuler whieh je ¥, limited in its scope and Purpose, usually designed and deployed fr P, application, and as such they only pantaty enough Memory (OF One tg), application, Tt is not Uneomy, , , , , , , , , , , , , , , , , , , , , , , 8 inte, NON for embeded ayaternis to HAVE NO Heer Intey, are never Meart, An example would: be, , as many applications, readable eutput, find embedded, , fay, hum), the types of computers (hat you wap, , 1h AePept teen Inpit mF give, , MT A CA The computer cantraliing your arith = Dri, System interacts With Vvatious sensory and aetiators to make and exer, decisions Without human, , vty rialized, teraction ard is extremely specializ:, , 4a, miniaturized to do so., , [5.2 OBUECTivES, , After learning this, , chapter you will be able to, l. Define and describe ¢}, ., , ye elements of an embedded ayatem, 2. Underst, , and how embedded s, , 5.3 GENERAL CONCEPT, LSS SENERAL CON(, , Embedded Systems are basically designed to regulate a physical varia, {such Microwave Oven) or to manipulate the state of some devices by sendin, Some signals to the actuators or devices connected to the output port syst, {such as temperature in A, , it Conditioner), in response to the input signal pri, by the end users or sensors which are connected to the input ports., , @ Hence the embedded systems can be viewed as a reactivesystem., , @ Examples of common user interface input devices arekeyboards,, button,switches, etc., , @ The memory of the system is responsible for holding the codefeontz, algorithm and other important configuration details)., @ An embedded system without code (i.e. the control algorithm)implemen q, memory has all the peripherals but is not capableof making decisio, depending on the situational as well as realworld changes., Memory for implementing the code may be Present on the processor, Z a implemented as a separate chip interfacingthe processor In, i Seance embedded system, thencontroller may contain im, cont, memory for storing code ie, Such <Sendion are called Micro-controllers with on-chip ROM, eg. Au, © Suc, AT89C51., , , , em worke with the help of two, , bedded system is a combination of 4 things ;, An em!, , a) Hardware, , b) Software =, , i a cream one specific task only,, And it is su
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ner whic, deployeq, ty for o, no USer j;., , it OF give, , a og, , ‘or ‘y, t a, Sy, , . code(contrg, , Jimplementeg, ing decisions, , processor of, ocessor In é, tain internal, M, eg. Atmed, Ja, i, , }, , :, 1, , for better understanding the concept of ES., , , , I 55, , Empeuse ~a~-— az Fi, , Diagrammatically an embedded System can be represented as follows :, , , , MEMORY, , SYSTEM OUTPUT, faa CORE PORTS, , OTHER, DEVICES, , Fig. 8.4(a) : Elements of an EB:, An embedded system is a computer s:, , , , , , , , , , , , , , , mbedded System, , ‘ ‘i : stem with a dedicated function within a, larger mechanical or electrical system, often with real-time computing, constraints. It is embedded as part of a complete device often including hardware, and mechanical parts (see Fig. 5.4(a)). Embedded systems control many devices, in common use today., , Examples of properties typical of embedded, general-purpose ones are low power consumpti, ranges, and low per-unit cost. This comes at, resources, which make them significantly mo, interface with. However, by building intelligenc:, hardware, taking advantage of possible existin;, network of embedded units, one can both optimally manage available resources, at the unit and network levels as well as provide augmented functionalities, well, beyond those available.!*! For example, intelligent techniques can be designed to, manage power consumption of embedded systems., , Modern embedded systems are often based on microcontrollers (ice. CPUs, with integrated memory or peripheral interfaces) but ordinary microprocessors, (using external chips for memory and peripheral interface circuits) are also still, common, especially in more complex systems. In either case, the processor(s), used may be types ranging from general purpose to those specialised in certain, class of computations, or even custom designed for the application at hand. A, common standard class of dedicated processors is the digital signal processor, (DSP). i, , Since the embedded system is dedicated to specific tasks, design engineers, can optimize it to reduce the size and cost of the product and increase the, Teliability and performance. Some embedded systems are mass-produced,, benefiting from economies of scale., , Embedded systems rarige from portable devices such as digital watches and, MP4 Players, to large stationary installations like traffic lights, factory controllers,, , largely complex systems like hybrid vehicles, MRI, and avionics. Complexity, , from low, with a single microcontroller chip, to very high with multiple, , ) Peripherals and networks mounted inside a large chassis or enclosure., , %, , APPLICATION SPECIFIC, Following are the case studies on some commonly used embedded systems, , computers when compared with, on, small size, rugged operating, the price of limited processing, re difficult to program and to, € mechanisms on the top of the, ig sensors and the existence of a
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S., , wi, , — Embedded System (SY. B.Sc.) (Sem,, , S.1 Washing machine, Let us see the, , i ; this will also he,, impor e machine; this e, understand the Portant parts of the washing, , working of the washing machine. Please refer to the image belo,, , , , Figure 5.5(a) : Parts of w ishing machine, i. Water inlet control valve, , Near the water inlet point of the washing there is water inlet control val, When you load the clothes in washing machine, this valve gets opened!, @utomatically and it closes automatically depending on ‘the total quantity of, water required. The water control valve is actually the solenoid valve., , 2. Water purr, , The water pump circulates water through the washing machine. It works i, two directions, re-circulating the water during wash cycle and draining the wate, during the spin cycle. :, , 3. Tub, , There are two types of tubs in the washing washing machine: inner ani _, outer. The clothes are loaded in the inner tub, where the clothes ee aoe F, rinsed and dried. The inner tub has small holes for draining the water., external tub covers theinner tub and supports it during various, of clotheswashing. fae, 4. Agitator or rotating 4 ;, he agitator is located inside the tub of the Washing machine,, , The ‘ 2 the washing machine that actually performs oe 2, the clothes. During the wash cycle the agitator rota, strong rotating currents within the water due to hi, , n of, , , , , , , , , , , . The rotation of the thes within
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=r tO the ime” Hg erabedaec systems, , , , The timer helps Setting the wash time for the clothes manually. In the, , automatic mode the time is set automatically dependi, clothes inside the washing machine, 'Y depending upon the number of, , 7. Printed circuit board (PCB), , The PCB comprises of the various, , : electronic components and circuits, which, are programmed to perform in uni, , que ways depending on the load conditions (the, thesloaded in the washing machine). They are, , int ‘evices that sense the various external conditions, and take the decisions accordingly. These are also called as fuzzy logic systems., Thus the PCB willcalculate the total weight of the clothes, and find out the, , quantity of water and detergent required, and the total time required for washing, the clothes. Then they will decide the time required for washing and rinsing., , 8. Drain pipe ;, , The drain pipe enables removing the dirty water from the washing that has, been used for the washing purpose. :, 5.5.2 Microwave Owen, inlet control vali, Following are parts of the microwave oven; this will also help us understand, , gets opent the working of the washing machine :, , tal quantity of & Se, valve, , , , , , chine. It worksi ©, , , , , , , , . Fig. 5.5(b) : Parts of a Microwave Owen, , A microwave oven consists of : ; oe, , high voltage transformer, which passes energy to the magnetron, vity magnetron, Bem feel, , rol circuit with a microcontroller, ;, , and : is
