THE EMBEDDED SYSTEMS

THE EMBEDDED SYSTEMS

21 November 2021

 EMBEDDED SYSTEMS


An embedded system is based on a microcontroller/microprocessor system of software and hardware which is design to carry out given functions within an electrical or mechanical system. Combined with computer software, hardware, and operating system, Embedded Systems can be programmable or fixed in capability. The user interface, input/output interfaces, display, and memory are parts of the Embedded System's hardware. Embedded System software is developed in a high-level language and then compiled to perform a specified function in hardware's non-volatile memory.The embedded device software is designed to perform a certain function. It is frequently written in a high-level style and then compiled to produce code that can be stored in a non-risky reminiscence within the hardware. The Software of the Embedded System includes application software, middleware, and firmware. An embedded gadget software application is created with the following three constraints in mind: Availability of machine memory, availability of processor’s speed, and when the system runs continuously, for events like prevent, run, and wake up, it's possible that power dissipation should be limited.




Basically, an Embedded System has three parts:


EMBEDDED SYSTEMS HARDWARE


  • Memory
  • Computer
  • Microprocessor,
  • Microcontroller
  • Peripherals
  • Analog to Digital Converters,
  • Digital to Analog Converters,
  • I/O Devices


EMBEDDED SYSTEMS SOFTWARE


  • Application Software
  • Middleware
  • Firmware


RTOS (Real Time Operating System)


It has a Real-Time Operating System (RTOS) that supervises application software and provides a method for the processor to follow a plan to control latencies and run processes according to schedule.  The system's operation is defined by the RTOS. It establishes the rules for the application program's execution. . A small-scale embedded system might not have an RTOS. 

At the center of the embedded systems, there is a circuit that is designed to perform computing for real-time operations, and its complexity differs significantly from task to task.

Known as computing systems, Embedded Systems have an extended spectrum; from no user interface (UI) to complex graphical user interfaces (GUIs). Also, the application ranges of the embedded systems are wide. From industrial machines, consumer electronics, agricultural devices to medical equipment, digital watches, airplanes, and toys are potential locations for embedded systems.


THE BASIC STRUCTURE OF AN EMBEDDED SYSTEM







The following components are inside the basic structure of an Embedded System:


ACTUATOR- With the output given by the D-A Converter, an actuator compares it with the actual output stored and then stores the approved output.

SENSOR- The sensor detects the physical quantity and converts it to an electrical signal that can be read by an embedded systems engineer or other electronic device. The detected quantity is stored in memory by a sensor.

A-D CONVERTER- - An analog-to-digital converter converts the analog signal supplied by the sensor into a digital signal.

D-A CONVERTER- The digital data provided to the processor is converted to analog data by a digital-to-analog converter.

PROCESSOR &ASICs- Processors analyze data to calculate output and store it in memory.


CHARACTERISTICS OF AN EMBEDDED SYSTEM


SINGLE FUNCTIONED- Embedded systems are usually single-functioned, meaning they do the same task repeatedly.


CONSTRAINED- Design metrics are tightly limited in all computing systems, but those on an embedded system can be exceptionally so. A measure of an implementation's features such as cost, size, power, and performance are called design metrics. It must be small enough to fit on a single chip, perform quickly enough to process data in real-time, and use as little power as possible to extend battery life.


REAL TIME- Many embedded systems must constantly react to changes in their surroundings and compute specified outcomes in real-time without any delay. Consider an automobile cruise control system, which constantly checks and responds to speed and brake sensors. It must compute acceleration or de-accelerations multiple times in a short amount of time; a delay in computing can result in the automobile losing control.


MICROPROCESSOR BASED- It should be microcontroller or microprocessor-based.


MEMORY- It must have memory because its software is usually stored in ROM. It does not require any additional memory in the PC.


CONNECTION- It must have connected peripherals so that input and output devices can be connected.


HARDWARE/SOFTWARE SYSTEMS- More functionality and flexibility are provided by the software. Performance and security are achieved through the usage of hardware.


TYPES OF EMBEDDED SYSTEM 



Embedded Systems can be divided into different types. Based on their performance and their functionality, they are classified into 4 categories: real-time embedded systems, standalone embedded systems, network embedded systems, and mobile embedded systems. Based on the performance of the microcontroller, they are classified into 3 categories: small scale embedded systems, medium scale embedded systems, and sophisticated embedded systems.




BASED ON PERFORMANCE AND FUNCTIONALITY


MOBILE EMBEDDED SYSTEMS 

These types of Embedded Systems refer to portable embedded devices such as laptops, cellphones, digital cameras, mp3 players, and calculators. Despite its limitation in terms of functionality and memory, Mobile Embedded Systems are portable, useful, and handy for people. 


NETWORK EMBEDDED SYSTEMS

Network Embedded Systems are related to the network to access the resources. The network connection can be wired or wireless, and the network connection can be internet, LAN, or WAN. Due to the flexibility and connection, it is the fastest-growing amongst them. All the network is controlled and accessed with the help of a web browser. The main usage areas of Network Embedded Systems are POS(Point of Sale) Systems, Automated Teller Machines(ATMs), home and office security systems. 



REAL-TIME EMBEDDED SYSTEMS

Real-time embedded systems describe giving the output response in a strictly tight time frame. This means the task has a defined operation time and the reaction must be done immediately with a little to no delay. If the system does not have any time constraints, it is called a general-purpose operating system. In the embedded systems industry, speed and real-time response are some of the most important parameters. Simultaneous communication in health and military industries can be critical to prevent any kind of mistake that might occur. To design real-time embedded systems, we need to have the time information the accurate as possible. However, providing real-time response can be difficult in some cases when there are performance and hardware constraints. Real-time embedded systems divide into two categories according to their dependency on time.


 If a time constraint is crucial in the task the system is called hard embedded systems. Here, control timing is the priority constraint. The examples are given as antimissile systems in the military and antilock braking systems in the cars. Missing a time parameter in an antimissile system can end in irreversible results such as the loss of a group of people and a huge financial loss. An antilock braking system in cars is developed for safe breaking and to prevent the wheels from locking. A missing constraint can result in the loss of human life. 


If timing delays are acceptable yet close time response is still important, it is called a soft embedded system. The consequences of missing a time are relatively insignificant. Soft embedded systems do not create irreversible outcomes when an application system occurs. 

Digital cameras, wireless routers, and global positioning systems (GPS) can be given as examples of soft embedded systems. The shutter speed of a camera happens with a small tolerance, the consequence when the delay increase can only be the dissatisfaction of the consumers. In the delays of wireless router systems, the user only experiences a low performance. While using the global positioning system, the user can miss a waypoint if a delay occurs. Neither of all results in a loss of human life or a catastrophe, unlike hard embedded systems. 



STANDALONE EMBEDDED SYSTEMS

Standalone Embedded Systems don’t need a host computer to function, it can work by themselves. It can take analog or digital input from the input ports, process, calculate, and convert the data, and then send the results to the linked device, which can control, drive, and display the connected devices.The best examples for Standalone Embedded Systems are microwave ovens, temperature measurement systems, mp3 players, and video game consoles.



BASED ON PERFORMANCE OF MICROCONTROLLERS


SMALL SCALE EMBEDDED SYSTEMS

A single 8 or 16-bit microcontroller is used to design Small Scale Embedded Systems. A battery can be used to power this microcontroller.The main programming tools are an editor, assembler, cross assembler, and integrated development environment for developing embedded software for small-scale embedded systems. The perfect examples for Small Scale Embedded Systems are washing machines, ovens, and automatic door locks.



MEDIUM-SCALE EMBEDDED SYSTEMS

Embedded systems with a single 16 or 32-bit microcontroller, RISCs, or DSPs are known as medium scale embedded systems. Medium Scale Embedded Systems have hardware and software complexities. The main programming tools are C, C++, JAVA, Visual C++, RTOS, debugger, source code engineering tool, simulator, and IDE for developing embedded software for medium scale embedded systems. The perfect examples for Medium Scale Embedded Systems are routers for networking and ATMs.



SOPHISTICATED EMBEDDED SYSTEMS

Sophisticated Embedded Systems need ASIPs, IPs, PLAs, scalable or configurable processors due to their hardware and software complexities. Sophisticated Embedded Systems are used for cutting-edge applications that need hardware and software co-design and components which have to assemble in the final system. Sophisticated Embedded Systems are ideal examples of graphical panels, touchpads, and cutting-edge solutions where both software and hardware are required for performance. The perfect examples for Sophisticated Embedded Systems are smartphones, multimedia systems. Also, with the world's leading AI platform NVIDIA® Jetson™ Embedded Systems, its users can create sophisticated embedded systems applications for industrial automation, quality control, smart city and various more.


Türkçe