Design of Intelligent Street Lamp Monitoring System Based on ZigBee and GPRS

2 single lamp controller design single lamp controller hardware circuit is mainly composed of [[2530110 ZigBee module, voltage and current acquisition circuit and street light switch control circuit.

The single lamp controller detects the voltage and current in real time, and uses these two parameters to judge the status of the street lamp. The voltage and current signals are power frequency signals, which cannot be directly connected to the AD port of the processor for sampling. The signals need to be processed by the converter and the signal conditioning circuit. In this paper, the TR0139-1C with a conversion ratio of 5A/1.5V is used for current conversion and the TR1139-1C with a conversion ratio of 220V/1.5V is selected for voltage conversion. The signals output by the converter are small amplitude AC signals, which need to be connected by two. A signal conditioning circuit consisting of a stage op amp. The voltage and current detection circuit of the single lamp controller is as shown.

As the scale of urban roads continues to increase, the number of street lamps used for lighting has increased significantly, and higher requirements have been placed on the data transmission rate, capacity, and system stability of the control. The traditional control management method is difficult to meet the modernization. In order to meet the needs of intelligent lighting control, in recent years, a large number of intelligent street lamp monitoring systems using wireless communication, power carrier, GPRS and other technologies have appeared.

GPRS is built on the basis of GSM system by using packet switching technology. It can transmit high-speed data on the network while being compatible with GSM. GPRS has the advantages of fast transmission speed, short access time and support of TCP/IP protocol, so GPRS The network is especially suitable for real-time transmission of small amounts of small data, which is in line with the design idea of ​​intelligent control street lamps 4-6. However, it is costly to equip each device with GPRS data transmission equipment. In response to this problem, the scheme uses a wireless networking scheme combining GPRS and ZigBee. Specifically, ZigBee network is used to realize small-scale cluster networking, and then GPRS-ZigBee gateway is used to realize long-distance wireless communication. 7-9. 1 Street lamp monitoring system consists of ZigBee and GPRS-based intelligent street lamp monitoring system through wireless transmission and The computer performs centralized monitoring and control of discrete street lamp objects. The overall block diagram of the system is shown.

The system is divided into three layers, the street light management software of the monitoring center, the street lamp centralized controller and the single lamp controller.

By embedding a ZigBee wireless communication module in each street lamp to enable their own network, single-lamp controller and centralized controller to communicate through the self-organized ZigBee wireless network, the centralized controller is realized through the GPRS wireless communication network and the 丨ntemet network and monitoring center. 2.2 The single-lamp switch control circuit designed by the switch control circuit is as shown.

The single lamp control node performs a light-off operation of the street light through the switch control circuit after receiving the command of the street light switch. The two parts of the switch control circuit separated by the optocoupler are the voltage detection circuit connected to the P0.5IO port of the CC2530, and the other part is the circuit that realizes the street light off control through the switch of the relay. The role of the optocoupler is to isolate the high voltage and low voltage, to avoid the interference generated by the high voltage circuit switch affecting the low voltage circuit, and to improve the stability and anti-interference ability of the system.

3 centralized controller design The centralized controller is mainly composed of microprocessor, GPRS module, ZgBee coordinator, real-time clock system, illumination intensity acquisition circuit and external memory.

GPRS communication module design GPRS module core circuit design as shown. The output signal of the serial port level conversion needs to be connected to GTM%0C through the level isolation circuit SN74LV245. In the SIM card circuit design, the SIM-GND signal needs to be grounded, and the decoupling capacitor should be added to the relevant signal line to ensure the signal on the SIM card is normal and reliable.

The serial communication between GTM%0C and STM8S207C is based on the AT command. The microprocessor STM8S207CB sends different AT commands to the GTM9000C module, and the module performs the corresponding operations according to the received AT commands.

The real time clock circuit is as shown. The real-time clock plays a very important role in the centralized controller. It is the key technology to realize the intelligence--the centralized controller can get the fall of each day according to the corresponding longitude and latitude. The time is taken out and compared with the internal real-time clock to judge the action of the switch street light. At the same time, through the real-time clock, the remote monitoring center can unify the time of the entire system, which provides convenience for fault analysis. The system adopts the new clock calendar chip DSI2C887 to realize various time acquisition and intelligent control. The MOT pin is grounded to make it communicate with the microcontroller STM8S207 to select the Intel mode. Since the DSI2C887 system is powered on, it should be added on the RESET pin. A low level, and maintained above 200ms, in order to ensure the clock works properly, so add a Song Shaojian, Xue Chunwei on the RESET pin. Wafer-level packaging based on Zigbee's urban streetlight intelligent monitoring speed meter provides a good way. The aluminum/germanium material used in the process scheme is compatible with the CMOS process, and provides an advantageous technical guarantee for the integration and miniaturization of the subsequent new MEMS devices. 33

Others

NANTONG MASTERPIECE TRADE CO.,LTD , https://www.yuaccessory.com

Posted on