1 Wire Temperature Measurement System Based on ZigBee Technology

2018 3rd International Conference on Information Technology and Industrial Automation (ICITIA 2018) ISBN: 978-1-60595-607-7

1-Wire Temperature Measurement System

Based on ZigBee Technology

Haiming Jing and Jinquan Li

ABSTRACT

By using ZigBee CC2530 wireless networking mode, a reliable and secure data network is designed. Temperature acquisition, transmission and communication with PC are realized. The 1-wire technology is used to transplant the temperature sensor DS18B20 search algorithm program into the ZigBee protocol stack code. It not only completes the temperature measurement of multiple points to be measured, but also completes the wireless transceiver of data. It solves the problem that a large number of codes need to be modified when the sensor needs to be replaced. On PC, the temperature value measured by ds18b20 can be viewed by serial assistant, and the real-time temperature monitoring can be completed. At the same time, the automatic identification of the sensor is realized, and the device can be expanded indefinitely. It improves work efficiency and saves development cost.

KEYWORDS

ZigBee networking; 1-wire Search algorithm; ds18b20.

INTRODUCTION

Temperature is a very common and important physical quantity in daily life, industrial production and scientific research. Many equipment operation, industrial and agricultural production and scientific experiments must be guaranteed to be carried out under certain temperature conditions. Therefore, temperature monitoring is widely used[1].

data measurement is insufficient, a large number of wiring will lead to a large workload [2]; Secondly, in the ordinary ds18b20 temperature monitoring system, the fixed-write ROM mode is adopted, each device needs to measure its r code in advance before it can work properly, once a failure occurs, it is difficult to maintain properly.

Based on ds18b20 digital temperature sensor and zigbee wireless network, a multi-point wireless monitoring system is designed, which solves the problem of multiple and complex lines in wired transmission. ds18b20 is a 1-wire bus digital temperature measurement chip developed by DALLAS Company in the United States. Its data output is digital signal output, which has the characteristics of strong anti-interference ability and high measurement accuracy[3]. Temperature sensors in each node are connected by a single bus and identified by a 1-wire search algorithm. Single-bus system, i.e. 1-wire bus system, transmits data through a single data line[4].The ROM codes of ds18b20 need not be predicted in advance. It is easy to set up, replace and maintain[5-7].

SYSTEM DESIGN

To design a real-time wireless temperature monitoring system which can be widely used in factories, warehouses and greenhouses. The system has three parts, temperature monitoring, wireless network data transmission and PC graphical interface display. The schematic diagram of the overall structure is shown in Figure 1.

There are three monitoring points on it, which can mount multiple temperature sensors. Because the 1-wire search algorithm is used for identification, the number of sensors can be easily increased, decreased and replaced according to the actual needs. The data of each node will eventually be transmitted to Coordinator G through wireless network, and the final result will be sent to PC through serial port.

Temperature

measuring point _Temperature

Each temperature sensor node of the system is automatically networked according to the preset working mode, and the data can be transmitted stably. The software on PC can display the temperature in real time, and can display the real-time curve of temperature change and store historical data. The system is divided into wireless transmission module, PC display module and temperature measurement module. By improving the routing algorithm based on ZigBee protocol, efficient and stable transmission paths can be automatically selected to achieve stable data transmission in the network.

HARDWARE DESIGN

The system consists of three parts. The first part is temperature acquisition, the second part is wireless transmission, the third part is the connection between the coordinator and the host computer.

The terminal node includes wireless communication, The terminal node includes wireless communication, Temperature data acquisition and data processing. DS18B20 has its own logic chip, which can directly convert temperature into digital signal for processing.

In wireless transmission and data processing, a new generation of CC2530 chip is used, which can be better applied to temperature detection in complex environment.

The serial communication chip used in this temperature measurement system transmits data for PL2303 and monitoring PC.

SOFTWARE DESIGN

1-wire bus technology is a computer application system consisting of only one master system and several slave systems on a bus. The system uses 1-wire bus technology to realize automatic reading of ID numbers of all sensors. Sensors and other devices that use their own network interfaces. The data communication and power supply of this interface only need one data line and one ground line, so the microcontroller can communicate with 1-wire sensor with only one port.

ds18b20 ds18b20

terminal node terminal node coordinator upper

monitor

Figure 2. Block diagram of the system.

Figure 3. Successful networking.

Figure 4. Physical chart.

SYSTEM INTEGRATIONAND DEBUGGING

CONCLUSIONS

The system uses search algorithm to successfully solve the problem that ID needs to be re-determined in the actual maintenance process, and uses ZigBee wireless network instead of a large number of routing methods.

The oscilloscope is used to measure the time sequence of each part of ds18b20, and the program runs successfully. The program is transplanted to ZigBee network. The system can use GUI interface to display the temperature and save the temperature of each time point in the database, which makes the temperature data of the point to be measured more convenient to manage.

REFERENCES

1. Tsinghua Xue. Research on High Precision Multichannel Temperature Measurement Technology. Wuhan Huazhong University of Science and Technology, 2007.

2. Jingpeng Hou, Jie Xiong, Yong Yuan. Temperature Control and Field Monitoring of Mass Concrete. Concrete, 2004 (5): 56-58.

3. Xiuxia Wang. Multi-channel Wireless Temperature Detection System Based on DS18B20 [J]. Journal of Hainan University Natural Science Edition. 2011, 12 (29): 362-366.

4. YanWang, LijuanWang, Ji-na Zhen. The Simulation of Multi-channel Temperature Detection and Display System Based on 1-Wire Bus in Proteus. Manufacturing Automation. 2013, 35 (7): 52-56.

5. Wubin Zhou. Zigbee Wireless Networking Technology Research. Master's Thesis of Central South University, 2009.

6. Ningning Liu, Lisong Chen, Lihui Qiu. Design of Temperature Monitoring System for Concrete Box Girder Based on ZigBee [J].Journal of Shijiazhuang Railway University: Natural Science Edition, 2014 (2): 37-40.GB/T 50279-98, Basic Terminology Standard of Geotechnical Engineering.