An embedded system is a controller 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. Embedded systems control many devices in common use today. Ninety-eight percent of all microprocessors manufactured are used in embedded systems. Modern embedded systems are often based on microcontrollers (i.e. CPUs with integrated memory or peripheral interfaces), but ordinary microprocessors (using external chips for memory and peripheral interface circuits) are also common, especially in more complex systems. In either case, the processor(s) used may be types ranging from general purpose to those specialized 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).
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 reliability and performance. Some embedded systems are mass-produced, benefiting from economies of scale. Embedded systems range from portable devices such as digital watches and MP3 players, to large stationary installations like traffic lights, programmable logic controllers, and largely complex systems like hybrid vehicles, MRI, and avionics. Complexity varies from low, with single microcontroller chip, to very high with multiple units, peripherals and networks mounted inside a large chassis or enclosure.
Types of Embedded Systems:
1. Stand Alone Embedded Systems:
2. Real Time Embedded Systems:
3. Networked Embedded Systems:
4. Mobile Embedded Systems:
5. Small Scale Embedded Systems:
6. Medium Scale Embedded Systems:
7. Sophisticated Embedded Systems:
- Small size and faster to load.
- More specific to one task.
- Easy to manage.
- Low cost.
- Spend less resources.
- These operating system is dedicated to one device so performance is good and use less resources like memory and micro-processors.
- Difficult to upgrade.
- If any problem occurs then you need to reset settings.
- Nearly not scalable.
- Hardware is limited.
- Troubleshooting is difficult.
- Difficult to transfer data from one system to other.