Intelligent building system hardware design and development

For traditional intelligent buildings, the design concept is based on the integrated wiring method. According to practice, this method has many disadvantages, such as waste of resources, increased difficulty of repair, very complicated wiring, and easy aging of later lines, etc. In contrast, the wireless sensor network can not only make up for the above shortcomings, but also can be flexibly expanded to realize remote monitoring, and can quickly and accurately diagnose network faults. Therefore, the combination of intelligent buildings with wireless sensor networks is an inevitable development trend.

Wireless sensor network integrates many technologies, including sensor, embedded, wireless communication technology, and network technology, and is a veritable high-tech integrated product. This is the principle of the whole area. Sensor nodes are placed in each area to collect and monitor information in real time, and then transmit it wirelessly, so as to realize the unification of human intelligence and physical environment. Therefore, wireless sensor networks are widely used in various fields of society. , Practice has proved that it can better meet people's needs, including urban management, military, medical, environmental monitoring, anti-terrorist operations and regional remote intelligent remote control, industrial and agricultural fields, it can be said to be ubiquitous, and has high research value . In the development of wireless sensor network technology, if the algorithm can be optimized to optimize the coverage, it will have better results and be more widely used.

1. Hardware design of intelligent building system

The overall framework of the intelligent wireless sensor network system adopts a layered structure based on the top of the sensor nodes in the actual environment, the next layer of transmission network, and then the next layer of base stations, and finally all base stations are connected to the Internet. During the operation of the system, the continuous building lighting of the sensor nodes, the real-time collection of smoke concentration, temperature and humidity, and the real-time collection of video or image information, all information can be obtained through the self-organized network after the sensor data collection, All data is sent to the gateway node. Another gateway sends the data to the base station via the transport network. According to the application requirements and distribution of different nodes in the wireless sensor network, it is divided into four modules, including processor module, wireless communication module, sensor module and power supply module. Now let's introduce these modules and corresponding representative chips.

2. Module composition of intelligent building system

2.1 Processor Module

There are many options for the processor, including single-chip microcomputer, PLC, etc. Here we choose the embedded processor, the ARM series ARM2131 chip of ARM7, which has the advantages of large capacity and fast speed, and can meet our needs. The ARM2131 development board uses an external 11.0592MHz crystal oscillator, which can increase the accuracy of the serial port baud rate, and the PLL and ISP can also support the LPC2131 microcontroller chip.

As shown in the figure, the JTAG interface circuit adopts the standard 20-pin JTAG emulation debugging interface proposed by ARM Company. When the system is reset and the internal interface of LPC2131 is enabled, JTAG emulation debugging can be performed directly at this time. The communication of LPC2131 is realized by connecting the computer through the serial port.

2.2 Wireless communication module

The chip selection of the wireless communication module requires low energy consumption and conforms to the corresponding communication standards, so the CC2420 chip is selected for node design. The chip is developed by Chipcon and complies with the ZigBee standard. It is the use of the global 2.4GHz chip for public broadcasting frequency sharing, and has collected the advantages of ZigBee technology, so the chip has been widely used in the field of wireless radio frequency. The chip also includes some additional features. And requires few external components, very stable performance, very low power consumption, and can ensure the reliability and effectiveness of short-distance communication. The antenna receives the signal, and the CC2420 chip will go through a series of processing to receive the signal first, such as a low noise amplifier, the signal is suitable for the transmission channel and I/O modulation circuit, frequency conversion processing, the mixed signal is filtered, amplified, and then converted by the AD converter It is a digital signal, and after automatic gain control and digital demodulation and despreading, accurate and undistorted data can be obtained at the output.

2.3 Sensor module

The sensor is a detection device, which consists of two parts, namely the sensitive original and the conversion original. It can detect the required information in real time, and can also collect the information, and convert the information into electrical signals according to certain rules, and then transmit it to the system. so that the system can use the information as needed. The acquisition module of the sensor mainly includes a sensing element, an auxiliary circuit, a preamplifier circuit, a filter circuit, and a postamplifier circuit. In the intelligent building monitoring system, the sensor must be the most important link in the whole system, and a large number of sensors need to be arranged in the building to cover the entire area, and it is best not to leave any dead spots, so as to realize the all-round monitoring of the entire building.

2.4 Energy supply module

LPC2131 only needs a 3.3V power supply, which provides power to the microcontroller core and I/O ports at the same time, but this power needs to be converted, here only three batteries (4.5V) or USB (5V) are provided. For power supply, L3 inductance limits the transient current in the circuit, and then filters through C16 and C20, and finally spxlll7-3.3 adjusts the power supply voltage to 3.3V. LPC2131, in order to reduce noise and reduce the probability of errors, usually isolated digital and analog power supplies use Ll, L2. To achieve this effect, spxl117-3.3 has the advantages of large output current, stable output voltage, and high precision. Capacitor 4.7uf improves transient response and stability during use.

Summarize

From the experience of smart sensors in wireless sensor networks, the three stages of smart wireless sensor development, smart sensor computing embedded sensors, sensor nodes' data acquisition and information processing capabilities, and increasing the capabilities of wireless smart sensors and wireless communication, wireless sensors The network has been widely used in China, including military, gas monitoring system, smart home, medical treatment, urban management, anti-terrorist operations, environmental monitoring, remote control in remote areas, industry and agriculture, etc. It is a very large research with exploration value. This paper mainly analyzes the hardware design of intelligent building in the application of wireless sensor network in node hardware. The intelligent building is the application background, and introduces the hardware design of wireless sensor network in detail, including four parts: processor module, wireless communication module, sensor module and power supply module .

The above is the example of intelligent building system development introduced by Shenzhen Zuchuang Microelectronics Co., Ltd. for you. If you have intelligent building scheme design needs, you can rest assured to entrust it to us. We represent a variety of single-chip microcomputers, voice chips, dual-mode Bluetooth ICs, and wifi chips. Brands include Songhan MCU, Yingguang MCU, Jerry Bluetooth, Ankai Bluetooth, Allwinner, and Realtek. Our technical services include: PCB design, microcontroller development, Bluetooth solutions, software and hardware custom development, APP development, small program development, WeChat official account development, etc. It can also undertake the design of intelligent electronic products, the development of living appliances, the research and development of beauty equipment, the application of Internet of things platform, the smart home control system, the development of TWS earphones, Bluetooth earphone speakers, the development of children's educational toys, the design of electronic education products, etc.