What is an embedded system?

Overview of embedded systems

An embedded system is a computer system that executes tasks in a unique electrical mechanical system. It comprises a computer's CPU, memory, and the usual input/output devices. It's usually found as part of a bigger device that has both electrical/electronic technologies & mechanical components. The requisite real-time computing is a constraint for embedded systems since they govern actual machine functioning of where they are found. Embedded systems are used to control a variety of current gadgets. In 2009, it was estimated that 98% of all microprocessors produced will be utilized in embedded systems.

What is the history of embedded systems?

The Apollo Guidance Computer which was the 1st contemporary real-time embedded computer system was built for the Apollo Program in the 1960s by Dr. Charles Stark Draper of the Massachusetts Institute of Technology (MIT). For the Apollo-Command and Lunar Module, the Apollo Guidance Computer was intended to gather data mechanically and conduct critical computations. The Intel-4004 was the first widely accessible CPU device that uses externally used memory & auxiliary chips were brought to use by Intel (1971).

Thanks to a guideline published by the National Engineering Manufacturers Association (NEMA) (1978), input, memory, and output components are combined into one chip as the CPU by the 80s, culminating in the building of a microcontroller.

The microcontroller-based embedded systems would eventually make their way into every facet of customers' daily lives, from smart cards and cell phones to traffic lights and thermometers.

How do embedded systems work? 

Embedded systems are always portions or components of a more complex device, as the term "embedded" implies. They're smaller CPUs that can be incorporated into other electrical mechanical systems for cost reduction and low-power consumption. CPU, memory storage, power supply, and communication ports are all common components. Embedded systems use communication ports for transferring data between the CPU and external devices, which are usually other embedded systems, using the communication protocol. The CPU evaluates this data using the barest minimum of software saved up in its memory. The software is usually meticulously tuned to the system's functionality.

The processor might be a microprocessor/microcontroller. Microcontrollers are essentially microprocessors with built-in features and memory. Microprocessors use distinct electrical components instead of including memory and peripherals on the chip. These can be used, however, because microprocessors are less integrated than microcontrollers. System on a Chip (SoC) is a term that is widely used to combine many CPUs and interfaces on a single chip. They're commonly used in higher-level embedded systems.

Embedded systems are frequently utilized in actual operating/functioning settings and interface with the hardware via a Real-Time Operating System (RTOS). The near real-time technique is appropriate at greater tiers of chip capacity, as specified by engineers who progressively determined that systems are typically efficient and that the activities are tolerable to minor changes in action time. In such a scenario, stripped-down versions of the Linux operating system are typically used. However, other systems, such as Embedded Java and Windows IoT, have been optimized to operate on these systems.

Characteristics of an embedded system

Embedded systems’ most distinguishing feature is that they are task-specific. These systems may also possess other certain characteristics:

They can be in a larger and more complex system for a single function since they are designed for specific duties inside the system rather than multiple activities. 

  • They can be a part of a larger system to execute a particular purpose.
  • They are frequently utilized for detecting and real-time computing on the Internet of Things devices, which are referred to as embedded devices that are internet-connected but don't necessitate a user to perform.
  • They can be either microcontroller-based or microprocessor-based, both are integrated circuits that provide system power. 
  • They can differ in ambiguity and function, affecting the software, firmware, or hardware they employ.
  • They can frequently be obliged to accomplish functions in order to keep the larger and more complex systems running smoothly.

Structure of embedded systems

Embedded systems come in varying sizes & complexity levels, although they all include three essential components:

Hardware: These systems use microprocessors and/or microcontrollers as their hardware. Microprocessors are comparable to microcontrollers in that they both relate to a CPU (central processing unit) that is combined with other fundamental computer parts like memory chips and digital signal processors (DSPs). Microcontrollers have all of these parts integrated into a single chip.

Firmware & software: The intricacy of this system software differs as industrial grade microcontrollers and embedded IoT systems, on the other hand, they typically run relatively basic software that uses little memory.

Real-time operating system: These systems, particularly smaller-scale systems, do not usually incorporate these. By overseeing software and establishing standards during program execution, RTOSes determine how the system functions.

A typical embedded system would include the components explained below in terms of hardware:

What is an embedded system?

Sensors convert physical sense data into an electrical signal. An analog electrical signal is converted to a digital signal via an analog-to-digital (AD) converter. Processors interpret and store digital signals. The digital data from the processor is converted into analog data by a digital-to-analog (DA) converter. Actual output is compared to memory stored output, and the appropriate one is chosen. The sensor receives external inputs, the converters make that data accessible while the processor converts that data into meaningful output for the embedded system.

Types of embedded systems

There are a few different sorts of embedded systems, each with its own set of functional needs. They are as follows:

Mobile embedded system:  Small systems that are engineered to be small and light are known as mobile embedded systems. Digital cameras are a good example for this type.

Networked embedded system: Embedded systems that are networked offer output to other devices via a network. Surveillance cameras and point-of-sale (POS) systems are two examples.

Standalone embedded system: Embedded systems that operate independently of a host system are known as standalone embedded systems. They execute a specific purpose, much like any other embedded system. Unlike others, they do not have to be part of a host system. This could be something like a calculator.

Real-time embedded system: This produces the desired result in a predetermined amount of time. Because they are in charge of timed tasks, they are frequently used in the medical sector, industrial, and/or military sectors. One example is a control unit of a manufacturing machine.

Classification by performance standards

Small scaled: In Small-scaled embedded systems frequently use an 8-bit microcontroller.

Medium-scale: This standard of an embedded system (16-32 bits) is used in moderate systems, and microcontrollers are frequently linked together.

Sophisticated scale: This frequently employs many algorithms, resulting in increased software and hardware complexity that may necessitate more complex software, a programmable CPU, or a microcontroller array.

Examples of embedded systems in different industries

Many industries and technologies employ embedded systems. Here are a few examples:

Automobiles: Several computers (possibly as many as 100) or embedded systems are used in new automobiles to handle various activities within the vehicle. Some of these systems are configured to achieve fundamental utilitarian functions, while others offer recreational or user-facing features. Examples of embedded systems found in consumer automobiles are backup sensors,  cruise control, navigation systems, suspension control, and airbag systems. The airbag system is another good example of a real-time capable embedded system.

Mobile phones: A mobile phone can be considered as a large, complex embedded system. However, there are several embedded systems in a cell phone, e.g., the cameras.

Industrial machines: These can include embedded systems, such as control units. Embedded automation systems that conduct specialized measurement and management functions are common in industrial machinery.

Medical supplies: Embedded systems, such as sensors/control mechanisms, may be present. Healthcare facilities, such as mechanical devices, must be particularly user-friendly in order to avoid machine errors that do not endanger human health. This means they'll often include a more complex OS and/or GUI designed for an exact UI.

The benefits and the downsides of embedded systems

They typically only perform one function, allowing them to run on relatively little power. They're also usually quite compact, allowing them to be readily jammed up with other features. When all of this is combined with impressive inexpensive development, you have a highly efficient method of equipment control.

Embedded systems cause extremely low maintenance, although they need direct supervision, whether it's adjustments to the hardware or programming.

A compact, low-cost, straightforward component that excels at performing one action continuously is ideal for 'fire & forget' devices. Commercial airliner entertainment systems, which can run Windows XP for considerably longer than a business computer, are a nice example of this.

Embedded systems are smaller than typical computers, which means they take up less room and are more portable. They use less electricity than bigger systems owing to their compact size.

Even with the major benefits attached to embedded systems, there are several drawbacks you must take note of before engaging in them to avoid problems occurring. This way, you can even choose from a fallback option if your firm relies on a system.

It's foremost to remember that these systems are notoriously hard to upgrade or even repair when they fail. This is owing to their 'embedded' structure, which means that critical parts are located deep inside the entire machine, and even the tiniest alteration has a huge influence on the rest of the system.

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