Home network control system of the hottest e5122

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E5122 home network control system

Abstract: the scheme, composition, hardware configuration, software design, working principle, function and technical performance of the home control system are discussed. This paper presents a remote control scheme based on Ethernet, in which the data is collected by single chip microcomputer and sent to Ethernet by Ethernet protocol processor

key words: ether; Control system; RTL8019AS; E5122

1 system introduction

the development of home intelligent control system is mainly based on short message technology, automatic control technology, computer technology, digital communication technology and encryption technology. The system uses the relevant network, computer system and controller to realize wireless remote control and data transmission by taking wireless network and wired network as the basic control instructions and data information transmission mode, and provides all-round digital services for family and community management through the specially set SMS control center and service center. The home intelligent control system has the functions of remote control, automatic alarm, calling community service, property management, etc. According to the needs of the user group, it can also be infinitely expanded to the life service, intelligent office and other directions

generally, as long as the equipment is connected to the Internet/Intranet, in principle, as long as the TCP/IP network protocol is implemented. TCP/IP protocol and its application is a complex system engineering. The establishment of the protocol needs a careful design process, and the implementation of the whole protocol is complex. It is difficult to implement this protocol in embedded system. In practical application, in order to better use the experimental machine for the majority of users, if the protocol is to be fully implemented, the more reasonable scheme is to directly use the integrated TCP/LP protocol chip to separate the central control unit and TCP/IP protocol processing unit of the system

on the other hand, the original TCP/IP can be simplified and only some protocols required by the actual application system can be retained, so that the core chip can not only realize the data transmission task of the network, but also complete the task monitoring. Because, simplifying the original TCP/IP protocol can greatly reduce the difficulty of system implementation, and can also improve the efficiency and reliability of the system

2 system working principle

the system is a home network control system based on e5122 network protocol processor. In this system, the three meter data in the family is taken as the acquisition signal, which is sent to the single chip microcomputer after being processed by the sampling and holding circuit, and then the single chip microcomputer sends the data to the e5122 network protocol processor through the serial port for packaging processing, so as to package the data into a TCP/IP protocol packet, and finally send the data packet to the Ethernet through the RTL8019AS Ethernet controller. This system uses CPLD chip EPM7128S as decoding and driving circuit. Because the home user terminal generally has low requirements for the data exchange rate (below 1MB/s), the general high-speed MCU can be used to write the TCP/IP protocol, which can not only meet the functional requirements, but also reduce the cost, and users are easy to accept such a price

3tcp/IP protocol parsing chip e5122

e5122 is a Feihong series network protocol processor developed by Shanghai Jingjing Technology Co., Ltd. The external crystal oscillator frequency is 22.1184MHz and the working voltage is 5V. It can provide API interface for hardware to realize TCP/IP protocol, and can communicate with the client in the form of I2C protocol or RS-232 interface. Its communication interface supports MPU with I2C interface, and also provides I2C driver for MPU without I2C interface to classify according to performance. The interface between e5122 and network is Ethernet interface, which can be connected to Ethernet through Ethernet control chip RTL8019. The maximum serial rate can reach 115.2kbps, and real-time transmission can be realized

e5122 is a special chip to complete TCP/IP protocol, which can be used to realize the protocol conversion between yitaihe serial ports. This device can provide a perfect network communication solution for serial port equipment only by connecting an external MCU. The MPU used in this system is 89C52 single chip microcomputer, and it only needs to call API function in the single chip microcomputer program. The device can be used as a server, that is, when connecting to the network for the first time, the client actively requests to connect to the server to listen as a passive end, accepts the active query access of the local inline remote client, and returns the device information to the client. The device can also be used as a client to actively communicate with the host in the local area or on the in-internet. The e5122 chip uses 32kbram externally to buffer Ethernet data. It uses a 256 byte (minimum 256 byte) Serial EEPROM (I2C bus interface) to store system parameters. Users can communicate with e5122 through serial port. The function of e5122 is to complete TCP/IP protocol and serial port communication protocol, which is also an important factor for the smooth progress of the experiment and the accuracy of the experimental results. It also supports the interaction between ordinary serial port and user equipment, and can realize network connection through external RTL8019AS control chip

4 hardware circuit design

4.1 interface circuit

in the specific use, due to the limitations of the single chip microcomputer itself, the JP pin can be connected to the high level by jumper during the design; The interface between e5122 and RTL8019AS is used to transmit network data

when the system runs for the first time, e5122 will initialize RTL8019AS and set its working mode and interrupt source. When RTL8019AS receives data, it will trigger e5122 interrupt. At this time, e5122 will select the register address and memory address of RTL8019AS through A8 ~ A13 and A15, and control and realize data reading. When data is sent to RTL8019AS through e5122, The system will set the corresponding register of RTL8019AS through the address line for data transmission

4.2i2c bus data memory

should be replaced in time

i2c bus is the abbreviation of interinterratedcircuitbus, namely "internal integrated circuit bus". I2

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