Characteristics of embedded systems and its applications

1. Embedded systems are designed to do some specific task, rather than be a general-purpose computer for multiple tasks. Some also have real-time performance constraints that must be met, for reasons such as safety and usability; others may have low or no performance requirements, allowing the system hardware to be simplified to reduce costs.
2. Embedded systems are not always standalone devices. Many embedded systems consist of small, computerized parts within a larger device that serves a more general purpose. For example, theGibson Robot Guitar features an embedded system for tuning the strings, but the overall purpose of the Robot Guitar is, of course, to play music.^[5] Similarly, an embedded system in an automobileprovides a specific function as a subsystem of the car itself.
3. The program instructions written for embedded systems are referred to as firmware, and are stored in read-only memory or Flash memory chips. They run with limited computer hardware resources: little memory, small or non-existent keyboard and/or screen.

User interface

Embedded system text user interface using MicroVGA

Embedded systems range from no user interface at all — dedicated only to one task — to complexgraphical user interfaces that resemble modern computer desktop operating systems. Simple embedded devices use buttons, LEDs, graphic or character LCDs (for example popular HD44780 LCD) with a simplemenu system.

A more sophisticated devices use graphical screen with touch sensing or screen-edge buttons provide flexibility while minimizing space used: the meaning of the buttons can change with the screen, and selection involves the natural behavior of pointing at what's desired. Handheld systems often have a screen with a "joystick button" for a pointing device.

Some systems provide user interface remotely with the help of serial (e.g. RS-232, USB, I²C, etc) or network (e.g. Ethernet) connection. In spite of installed client software and cables are needed this approach usually gives a lot of advantages: extends the capabilities of embedded system, avoids the cost of a display, simplifies BSP, allows to build rich user interface on PC. One of the well established model in this direction is the combination of embedded web server running on embedded device and user interface in web browser on PC (typical for IP cameras and network routers).