Embedded System is a fully embedding controlled device inside, special computer system designed for specific applications; the embedded system is the equipment to control, monitor, or assist the equipment, machinery or for the operation of the factory. Different from general-purpose computer systems such as personal computers, embedded systems usually performs predefined tasks with specific requirements. Due to the embedded system only for a special task, designers can optimize it; reduce the cost by reducing the size. An embedded system usually produces large amounts of products, so that a single cost savings can be carried out with the production of hundreds of thousands of amplification
Usually, the embedded system is an embedded processor control board which is stored in ROM. In fact, all equipment with digital interface, such as watches, microwaves, VCR, automotive and others, all use embedded systems, some embedded systems also contains the operating system, but most embedded systems are implemented by a single program of the control logic.
The core of the embedded system is composed of one or several microprocessors or single chip microcomputer which is used to execute a few tasks. The software on the embedded system is usually the same as that of the common computer which can run the software that users choose, so it is often called "firmware".
2. Internet of Things
With the popularity of medical electronics, smart home, logistics management and power control, embedded system uses its own accumulated experience, attaches importance to and grasp the opportunity, to think of a way in combination with a mature platform and products based on and application of sensing unit, extended the support capacity of the associative perception, to explore some areas of networking applications. As an important technology of the Internet of things, embedded system, embedded system is helpful to deeply and comprehensively understand the nature of the Internet of things.
This has two meanings: first, the Internet is still the core of the Internet of things, is on the basis of the Internet and the extension of the network; second, the user terminal extends to any goods and articles, the exchange of information and communication must be intelligent terminal with the construction of the embedded system. Therefore, networking system is the radio frequency identification (RFID), infrared sensors, global positioning system (GPS), laser scanners and other information sensing equipment, according to the agreement, the anything connected to the Internet, information exchange and communication system architecture.
The Internet of things not only provides the connection of the sensor, it also has the ability of intelligent processing, can carry out the intelligent control to the object, this is the embedded system can achieve. Internet of things will be a combination of sensors and intelligent processing, the use of cloud computing, pattern recognition and other intelligent technologies to expand its application to analyze process and deal with the data obtained from the sensor, to meet the different needs of different users, to discover new application fields and application modes.
1). The system kernel is small.
2). Strong specialty
3). Simplified system
4). High real-time system software (OS) is the basic requirements of embedded software.
5). Embedded software development to be standardized, it is necessary to use a multi tasking operating system.
6). Embedded systems development needs tools and environment.
7). Embedded system combines with the specific application organically, upgrading is carried out synchronously.
8). In order to improve the operating speed and system reliability, the software in the embedded system is generally solidified in the memory chip.
4. System Components
1) Hardware layer
Embedded microprocessor, memory, universal device interface and I/O interface
2) The middle layer
Hardware initialization of embedded system, hardware related device driver
3) System software layer
5. Application Areas
1) Industrial control
2) Traffic management
3) Information appliances
4) Family intelligent management
5) POS network
6) Environmental engineering
6. Development Trends
1). Embedded development is a system engineering, so it requires that the embedded system manufacturers not only provide the embedded software and hardware system itself, but also need to provide a powerful hardware development tools and software package support.
2). The requirements of network and information with the increasing maturity of Internet technology, the improvement of bandwidth, making the previous single function equipment such as telephone, mobile phones, refrigerators, microwave ovens and other function are no longer single, the structure is more complicated.
3). Network interconnection has become an inevitable trend.
4). Simplify the system kernel, algorithm; reduce power consumption and hardware and software costs.
5). Provide a friendly man-machine interface.
7. System Solutions
1) Application schemes in the remote monitoring of power network based on embedded system
2) RFID handset system based on embedded system
8. Knowledge and Learning Methods
1) C development experience
2) Network, operating system, system structure
3) The concept of embedded system
4) Embedded development practice
5) Hardware development
9. Important Concepts
1) Embedded processor
2) Real time operating system
System response time, task lane changing time, interrupt delay
Four states: executing, ready, suspended, dormant
3) Time sharing operating system
4) Multi task operating system
1) Automatic teller machine (ATM).
2) Aerospace electronics, such as inertial navigation systems, flight control hardware and software, and other integrated systems for aircraft and missiles
3) Mobile phones and telecommunications switches
4) Computer network devices, including routers, time servers and firewalls
5) Office equipment, including printers, fax machines, fax machines, multi-function printers (MFPs)
6) Disk drives (floppy drives and hard drives)
7) Automotive engine controller and anti lock braking system
8) Home automation products, such as thermostats, air conditioners, sprinkler and safety monitoring system
9) Hand-held calculator
10) Household appliances, including microwave ovens, washing machines, televisions, DVD players and recording devices
11) Medical equipment, such as X ray, magnetic resonance imaging
12) Test equipment, such as digital storage oscilloscope, logic analyzer, spectrum analyzer
13) Multi function watch
14) Multimedia appliances: Internet radio receiver, TV set top box, digital satellite receiver
15) Personal digital assistant (PDA), which is a small hand-held computer with personal information management and other applications.
16) Mobile phones with other capacity, such as cellular phones, personal digital assistants (PDA) and Java mobile digital assistants (MIDP)
17) Programmable logic controllers (PLCs) for industrial automation and monitoring
18) Fixed and portable game consoles
19) Wearable computer
1) Control cycle
2) Non preemptive task
3) Preemptive timer
4) Preemptive task
5) Micro core and outer core
6) Virtual machine
7) Check point calculation
8) Office (macro kernel) operating system
9) Exotic custom operating system