2, embedded system concept: embedded system is application-centered, based on computer technology, software and hardware can be tailored to adapt to the application system on the function, reliability, cost, volume, power consumption and other strict requirements of the special computer system. The core of an embedded system consists of one or more microprocessors or microcontrollers pre-programmed to perform a small number of tasks.
3, the full name of embedded embedded system refers to the device used to control, monitor or assist the operation of machines and equipment. Embedded system is a kind of specialized computingA mechanical system, as part of a device or equipment. A general embedded system is an embedded processor control board in which the control program is stored in ROM.
4, embedded system: is a completely embedded in the controlled device, designed for a specific application of the special computer system, according to the British Institute of Electrical Engineers definition, embedded system for control, monitoring or auxiliary equipment, machinery or equipment used for factory operation. Unlike general-purpose computer systems like personal computers, embedded systems typically perform pre-defined tasks with specific requirements.
5. Embedded systems, JaneIn short, it is an integration of software and hardware designed for a specific application that controls, monitors, or AIDS the operation of equipment, as defined by IEEE (International Society of Electrical Engineers). The core of this system is its application orientation, which must be closely combined with the actual needs to play its advantages. It integrates computer technology, semiconductor technology, electronic technology and industry applications, and is technology-intensive and constantly innovative.
1, the difference between acoustic electric toothbrush and electric toothbrush The principle of the two is different: electric toothbrush uses a high-speed motor to rotate the brush headThe vibration achieves the effect of cleaning teeth, while the ultrasonic toothbrush uses the cavitation effect of ultrasonic energy in the periodontal membrane to remove periodontal bacteria and impurities. They have different cleaning ranges. The cleaning range of the ultrasonic toothbrush can cover all parts of the periodontal tissue, while the cleaning range of the electric toothbrush is smaller.
2, the specific use steps: carefully insert the brush head into the swing shaft, and leave a certain gap between the brush head and the main body to reserve space for the normal work of the brush head. To prevent toothpaste from splashing, apply a small amount of toothpaste to the brush head before use. Generally speaking, sonic electric toothbrushes save more toothpaste than manual toothbrushes. Brush head firstMoisten and place in your mouth, then start the toothbrush. Move the toothbrush slowly at a 45° Angle between the bristles and the gum line.
3, the advantages of acoustic electric toothbrush: strong cleaning ability. Brushing can remove plaque, followed by cleaning stains and teeth stains. The cleaning ability of sonic electric toothbrush is much higher than that of general soft toothbrush, which can eliminate a certain proportion of dental plaque, and can reasonably prevent the occurrence of gingivitis and periodontitis, and then maintain the physical and mental health of the oral gum.
4, the proper operation method of acoustic electric toothbrush: properly install the brush head: in the case of installing the brush head, be sure to determine the brush headFirmly fit into the soft-bristled toothbrush shaft to prevent the brush head handle from coming loose. Before the application of acoustic electric toothbrush, pay attention to the application of warm water to soak the brush head to adjust the flexibility of the toothbrush, such as immediately take cold water to open the brush, the toothbrush is hard and the vibration frequency is not integrated, so there is gum bleeding.
5, the method of applying acoustic electric toothbrush is similar to the general soft toothbrush, but the acoustic electric toothbrush does not need to use its own hand brush, and the actual cleaning effect is stronger. Sonic electric toothbrush application common problems in the case of whitening toothpaste use to control, the general length of whitening toothpasteA brush head is usually fine.
6, how to choose the acoustic electric toothbrush head In the case of selecting the acoustic electric toothbrush head, it is best to use the small and medium-sized brush head. The head of the sonic electric toothbrush is too large, and it may not be possible to clean small areas such as tooth gaps. The small and medium-sized acoustic electric toothbrush head can also deep clean the inside of the teeth to clean up, so the small acoustic electric toothbrush head may clean up the actual effect of the large acoustic electric toothbrush head will be better.
1, IC card readIC card reader is the bridge between IC card and application system, which is called interface device IFD in ISO international standard. The CPU in the IFD is connected to and communicates with the IC card through an interface circuit. IC card interface circuit is a crucial part of IC card reader, according to the actual application system, you can choose parallel communication, half duplex serial communication and I2C communication and other different IC card read and write chips.
2, it is a microelectronic chip embedded in the ISO 7816 standard card base, made into a card form; Has been very widely used in packagesIncluding finance, transportation, social security and many other fields. IC card reader is the bridge between IC card and application system, which is called Interface Device (IFD) in ISO international standard. The CPU in the IFD is connected to and communicates with the IC card through an interface circuit.
3, the contact IC card is the IC chip is packaged in a standard PVC card, relying on the direct contact between the bare chip and the reader card to read and write data. Contact IC card contact sheet, exposed on the surface of the IC card, in some cases (such as bent, defaced) cause IThe device's resources are relatively limited, so the kernel is smaller than traditional operating systems. Dedicated strong. The individuality of embedded system is strong, the combination of software system and hardware is close, and the general hardware system should be transplanted, even if the same brand and the same series of products need to be modified according to the changes and increases of the system hardware.
2, highly integrated real-time response ability, low power consumption and strong customization. High system stability. The software code is demanding. Scalability and modular design. Strong integration with other technologies. Strong hardware support capability. Strong software support capability. possessAdaptability to a wide range of application fields.
3, specificity is very strong: the advantage of embedded operating system is very strong personalization, the combination of software system and hardware is very close, generally for the hardware system transplantation, even in the same brand, the same series of products also need to be modified according to the changes and increases in the system hardware. At the same time, for different tasks, it is often necessary to make large changes to the system, and the compilation and download of the program should be combined with the system.
4, embedded system is a special type of computer system, its main characteristic is that it has strict functional limitations and resourcesLimit. The main characteristics of embedded systems are as follows: Miniaturization: Embedded systems usually require a hardware platform with small volume and low power consumption. This makes them suitable for many different application areas, such as medical devices, vehicles, smart homes, and more. Real-time: The embedded system must be able to complete its task within a specified time.
5, characteristics are as follows: It is a "special" computer system. Embedded system is usually oriented to a specific task, and is different from the general PC computer platform, is a "dedicated" computer system. The operating environment varies greatly.
1, normal is the first IC after the program, which according to the program to choose the microcontroller. It depends on what type of microcontroller your program is written under what environment, otherwise the program will not be downloaded, and even if it is downloaded, it may not be used. The types of microcontrollers are divided into 8 bits, 16 bits and 32 bits according to the data bits. According to the manufacturer, atmel, nxp, st, ti, intel, Huabang, stc, philips, moto Roller and so on.
2, singleThe computer is a commonly used microcontroller, A2 and A4 are two models in the 51 MCU series. The main differences are as follows: Architecture: A2 and A4 use different architectures. The A2 uses the traditional 8051 architecture, while the A4 uses the enhanced 8051 architecture. Performance: A4 has higher performance than A2. The A4 has a higher frequency, faster instruction execution, and more memory and peripheral interfaces.
3 CKS32F103C8T6 and STM32F103CBT6 are two different brands of microcontrollers, respectivelyIt is manufactured by Sinostar Microelectronics (CKS) and STMicroelectronics. They all belong to the STM32F1 series of microcontrollers, but may differ in some technical specifications and performance.
First of all, AVR microcontroller is a high-speed embedded microcontroller: AVR microcontroller has a prefetch instruction function, that is, when executing an instruction, the next instruction is taken in advance, so that the instruction can be executed in a clock cycle. Multi-accumulator type, fast data processing speed. AVR MCU has 32 general working registers, equivalent to 32 overpasses, which can be used quickly. Fast interrupt response. AVR microcontroller has multiple fixed interrupt vector entry addresses, which can respond to interrupts quickly.
Architecture difference32 MCU is a microcontroller based on 32-bit architecture, which has 32-bit registers, data bus and address bus, and can efficiently process 32-bit data. In contrast, 51 MCU is based on 8-bit architecture, its register, data bus and address bus are 8-bit, and can only process 8 bits of data at a time.
ATMEL single-chip microcomputer, that is, 51 single-chip microcomputer, can also be called AVR single-chip microcomputer, AT80, AT90 and other series; pic series microcontroller. Of course, there is also the Shengqun microcontroller of Taiwan Shengqun company (the company has targeted students in the mainlandCarry out SCM application ability competition), EMC SCM of Taiwan Yilong Company, PHLIPIS also has 51 SCM, TI company also has.