Design of ZigBee infrared remote Monitoring System

Modern security monitoring is increasingly being valued. It is generally composed of image acquisition, transmission and storage system. The use of high-precision cameras with advanced image processing technology and transmission technology. Although its security monitoring performance is very good, but there are large investment costs, real-time alarm performance is poor. Large amount of data, the shortcomings of concealment. In view of these shortcomings, some applications can also use infrared monitoring as a means of monitoring.

Infrared detectors since 1800 year was first produced, after more than 200 years of development, technology has been very mature. It refers to the non-visible infrared radiation detected, and transformed into a measurable signal technology, with good adaptability, good concealment, strong confidentiality, stable performance and other advantages. The real-time detection and tracking of the object can be realized by detecting the infrared ray of the specific band.

An infrared remote monitoring system based on ZigBee Wireless module technology is introduced in this paper. ZigBee Wireless Module digital transmission is a short-range wireless communication technology, with low power consumption, low cost, large network capacity, high reliability and security, and low development cost. The entire system uses infrared detectors to monitor whether a particular area is being used. The detection error is small, and the data is transmitted by ZigBee Digital transmission module . The utility model has the advantages of low power consumption, cheap and high efficiency.

1 System Solutions

The system is mainly composed of 3 parts, namely ZigBee Data Acquisition part,ZigBee data transmission module and monitoring part. ZigBee Data acquisition by the human Body Infrared Detector module hc-sr501 completed, in order to facilitate the control of data collection is carried out, paired with a wireless remote controller. hc-srs01 quiescent current of less than 50uA, suitable for battery power, the detection angle of about the degree of taper angle, working distance within 7 meters , do not wear walls, suitable for indoor use, When the body enters the sensing range, the output is high, the auto-delay, and the output is low when no one is there.

The remote control uses the radio remote control method, uses the PT2262,PT2267 encodes, decodes the chip to make, carries on the remote control in the 433M Common frequency band. ZigBee Wireless module transmission part includes ZigBee terminal node. Routers and coordinators. The terminal node is used to connect the infrared detector and the wireless remote controller to receive the data; the router is used to relay data: The Coordinator is responsible for the formation of ZigBee Digital Network and receiving data, the use of RS232 serial data cable, data transmission to the central computer. The interface of the Monitoring section is written in LabVIEW to process and display the received data information. The system needs to implement the function is: the use of infrared detectors for ZigBee data acquisition. and send the collected data to the Zigbec terminal node, through the wireless remote control of the handheld remote end, control ZigBee Digital Transmission terminal node whether to receive data. The received data is passed from the endpoint to the router, which is then passed by the router to the coordinator, eventually to the central computer and displayed on the monitoring interface.

Figure L system architecture diagram

2 Hardware design

2 . 1 Data acquisition module

In the system, the human infrared detector is connected to the end node so that the collected data can be passed directly to the end node. The remote controller is used to control whether the microcontroller in the terminal node receives the infrared detector signal. The reception of the signal here is done by controlling whether or not the microcontroller is in the interrupt state. Multiple infrared detectors can be arranged on a monitoring side. For multi-area coverage, all detectors are connected in parallel and then to the end node, as shown in2 .

Figure 2 Data acquisition end placement Diagram

2 . 2 Wireless transmission module

When ZigBee data acquisition is complete. It is necessary to use the wireless transmission network to pass data to the central computer. ZigBee Wireless Module transmission network mainly by the ZigBee Digital Transmission terminal node. Routers and coordinators. The terminal node is the data acquisition source, realizes joins, exits the network the function; The router is responsible for the search, establishes the network routing information, expands the network scope, the coordinator is the entire Network center, is responsible for the network establishment and the data disposition.

ZigBee There are 3 types of network topology, namely, star structure, net structure and tree structure, we use the tree structure,3 shows.

Fig. 3 ZigBee clustered topological structure

The data of the end node is passed to the router or coordinator, and the receiving data of the router is forwarded to the Coordinator or to the neighboring router. To achieve the role of data transfer. The core of ZigBee Network is TI CC2530 microprocessor. It is a model for IEEE802. A. 4,ZigBee and rf4ce application of Real on-chip system solutions. The ability to build networks at very low cost. The system has different operating modes, especially for ultra-low power requirements. Integrated with enhanced 8051 core. Combined with the z-stack protocol stack, you can easily build your own ZigBee Wireless Module Communication network.

3 Software Design

In terms of software. Use the IAR Embedded Workbench Integrated development tool as a programming tool for CC2530 . The terminal node program flow diagram is shown in Figure 4 .

Figure 4 terminal node program flowchart

When the program starts, the onboard element is initialized and the ZigBee Digital transmission network is added. The external interrupt of the IO port is then set for the detection of the Human Infrared Module monitor signal and the handheld remote control signal ( the handheld remote controls whether the system turns on monitoring mode ). After the system enters the boot monitoring mode, the terminal node begins to receive signals from the human infrared sensor. The human body infrared sensor is set to repeat the trigger mode, that is, if the human body infrared sensor detects the human body, the sensor output high level, in the delay time period, if there is a human body in its sensing range activity, its output will remain high level, until the person left after the delay will be high level into low level.

When the terminal node receives the infrared signal of the human body, it sets the alarm flag bit and sends the alarm information to the monitoring side through the ZigBee Network: The program then enters the waiting alarm state. The user can now release the alarm by hand-held remote control or a command to dismiss the alarm from the monitor. The endpoint unlocks the alert. And will successfully release the alarm information upload monitoring side. After this, the system re-open the monitoring state, so that the program has been a reincarnation, the terminal node so that the reciprocating work. The Coordinator program flow diagram is shown in 5 .

Figure 5 Coordinator Program Flowchart

After the system is initialized, an energy scan is performed in the range of the specified network channel, which is monitored on each channel. To obtain the energy level of each channel, select one of the channels of interference and least conflict to establish a network, which is shown in process 6 .

Figure 6 ZigBee Group Network flowchart

The second is to configure the serial port. Realize the communication between the Coordinator and pc of the host computer. Finally enters the receiving information status, waits for the terminal node to upload the information. Every packet is received, the whole packet data is sent through the serial port, or the command of the host computer is forwarded to the terminal node. The computer software running on the PC is written using LabVIEW software. Through the PC serial port, the program receives a string of packets sent by the microcontroller. The infrared detection data is parsed in a predefined frame format. A warning light on the interface informs the user of the status of the monitoring area. While The corresponding dismiss button is set on the interface. After the infrared sensor has detected the infrared signal of the human body and the alarm information occurs, the alarm can be lifted off by the alarm button on the host computer.

4 Concluding remarks

This paper introduces a scheme of using ZigBee Wireless module and infrared detection to realize real-time monitoring, and uses infrared sensor to make ZigBee data acquisition and operation convenient and practical. The system has low price, mature technology and stable performance. Detectors can be placed in a wide range, adaptable to the environment, good concealment, can be used for some low-cost, high-real-time monitoring scenarios. In addition, the basis of the system is ZigBee digital transmission network, when the network is completed, can be used in the terminal node with different types of sensors, you can use to collect different data information. The system is highly scalable.

Design of ZigBee infrared remote Monitoring System