What are the advantages of ZigBee technology? The function of ZigBee system is introduced in detail.

The application direction of ZigBee technology is located in home automation, building automation, sensor application and so on. The wireless network communication module of the system adopts the real system-on-chip (SoC)COMS solution CC2430. This scheme can improve the performance and meet the requirements of low cost and low power consumption for 2.4GHzISM band applications based on ZigBee. It also includes a DSSS (direct sequence spread spectrum) RF transceiver core and an industrial-grade compact and efficient 805 1 controller. The wireless data transmission module adopts DL6200 module, and users can communicate through GPRS network only by using the familiar serial communication knowledge.

Technical advantages of 1 ZigBee

The technical advantages of ZigBee are as follows:

(1) Save power. Because of the short working cycle and low power consumption of sending and receiving information, ZigBee technology can ensure that two batteries of No.5 can be used for about 6 months to 2 years by adopting sleep mode. The power consumption corresponding to different applications is naturally different.

(2) reliable. ZigBee technology uses collision avoidance mechanism to reserve special time slots for communication services that need fixed bandwidth to avoid competition and conflict when sending data. The MAC layer adopts the data transmission mechanism of complete acknowledgement, and each sent data packet must wait for the acknowledgement information of the receiver.

(3) Low cost. The module is cheap, and the ZigBee protocol is free of patent fees.

(4) Short time delay. It is optimized for delay-sensitive applications, and the communication delay and activation delay from sleep state are very short. The typical device search delay is 30ms, the typical sleep activation delay is 15ms, and the active device channel access delay is15 ms.

(5) The node communication settings are easy to configure.

(6) Large network capacity. ZigBee can be networked in star, mesh and tree structure, and a larger network structure can be formed by connecting any nodes. Theoretically, it can connect as many as 64,000 nodes. 1 ZigBee network can accommodate at most 254 slave devices and 1 master devices, and at most 1 00 ZigBee networks can exist in1area at the same time.

(7) Safety. ZigBee provides data integrity check and authentication functions. The encryption algorithm adopts AES- 128, and each application can flexibly determine its security attributes.

(8) global universality and complete openness. The ZigBee standard protocol makes the communication between ZigBee devices easy.

Technical characteristics of 2 CC2430

CC2430 chip continues the architecture of previous CC2420 chip, and integrates ZigBee RF front end, memory and microcontroller on a single chip. It adopts 1 8-bit MCU(805 1) and has 128KB programmable flash memory and 8KB RAM. It also includes analog-to-digital conversion (ADC), multiple timers, AES- 128 coprocessor, Watchdogtimer, sleep mode timer of 32kHz crystal oscillator, PowerOnReset circuit, BrownOutDetection circuit and 2 1 programmable I/O pins. CC2430 chip adopts 0. 18? MCMOS process; In receiving and transmitting modes, the current loss is less than 27mA and 25mA, respectively. The characteristics of CC2430' s sleep mode and extremely short time to switch to active mode are particularly suitable for those applications that require a long battery life.

3 GPRS data transmission module DL6200

The core hardware of DL6200 module is designed and produced by GPRS chip produced by world-renowned mobile communication product manufacturers, which has high reliability. When using DL6200, you only need to be familiar with serial communication knowledge, and you can communicate through GPRS network. Do not care about the RF circuit part of the module (using the mobile operator's public network) and related hardware connections; Regardless of the at instruction set, all operations related to AT response are completed by the DL6200 module inside the module; Don't care about the knowledge of TCP/IP protocol and Internet: Because GPRS module is an Internet-based communication mode, it has to deal with the Internet in use, and all information exchange with the network is automatically completed by DL6200 module without user participation; Users don't have to have a fixed IP address alone; There are two transmission formats: format and transparent transmission; It has a normal working mode and a power saving working mode; Direct connection to various configuration software without special driver; Support bus-based passive data transmission mode.

4 system structure and working principle

4. 1 System structure and function

The system consists of external network and internal network. The external network consists of GPRS data transmission module and PC, and information can be transmitted between them through TTL\RS232\RS485. The level interface of the upper computer is TTL.

The intranet consists of PC and ZigBee wireless data communication module, which are connected by serial port. ZigBee network consists of coordinator, router and terminal equipment. Coordinator and router are called full-function equipment FFD, and terminal equipment is called reduced-function equipment RFD. Because the equipment of the system is relatively simple, the star networking mode is adopted, with window magnet and door magnet as terminal equipment and ZigBee wireless module as coordinator. The system is simple in structure, so there is no need for a router. As shown in figure 3.

(1) The user sends a short message command to the GPRS data transmission module DL6200 through the GSM mobile phone of the external network. After receiving the command, DL6200 interprets the command. After the explanation, it will be sent to the ZigBee wireless communication module CC2430 in the intranet, which will send the command to the corresponding terminal equipment, and the terminal equipment will take corresponding actions after receiving the command.

(2) After receiving the command, the terminal equipment will respond to the upper layer after making corresponding actions, and transmit the data needed by the upper layer to the upper layer equipment through the CC2430 module. The upper computer receives the information of the terminal equipment and sends it to the user's mobile phone in the form of short message through DL6200.

(3) When there is an interrupt response, if there is a thief at home, the alarm device will be triggered, and the terminal device will send a message to the user at the first time, indicating an alarm.

4.2 Hardware design of the system

DL6200 doesn't need to care about AT instruction set. There is no need to care about the knowledge of TCP/IP protocol and Internet, and all information exchange with the network is automatically completed by DL6200 module. Directly connect various configuration software without special driver. These characteristics of DL6200 make the hardware design easy. Its RXD and TDX must be connected with the RX and TX of ZigBee to send and receive data.

4.3 Software design of the system

The system software mainly completes data acquisition and data transceiver through ZigBee network protocol operation, including initialization, transceiver program design, alarm signal monitoring, remote control instruction processing and execution.

The sending and receiving of the system adopts the ping-pong sending function.

5 conclusion

ZigBee wireless module has the advantages of low power consumption and low cost, and will be popularized to every household in the near future under the condition of meeting people's demand for transmission rate. In addition, the use of wireless network saves the burden of redecorating. ZigBee wireless network can increase or decrease its nodes at any time, and has self-organizing ability to the network. Therefore, the economic degree of goods and the difficulty of technology become the inevitable conditions for development.