Wireless Sensor Network Research and Application In Agricultural Environment Monitoring Meng Hao Gu Lichuan Sun Fukang Instructor : Professor Frank Y.S. Lin Presented by Ray J.P. Lo School of Information and Computer of Anhui Agricultural University, Hefei, China School of Computer of Anhui University of Architecture, Hefei,China

Agenda  Introduction  System Structure  Software  Conclusion

Introduction

 Recently, many researches have been involved in wireless sensor networks.  To establish practical application systems, there are many technological difficulties needed to be solved, such as : Production cost of systems Volume of sensors Power support time Network protocols

Introduction (cont ’ d)  In the application of agricultural informatics, there are wide application requirements in data transmissions by using wireless sensors.  This research focus on the agricultural environment data collection and application by using 433MHz with one direction data transmission wireless sensors.

System Structure

 This research wants to use normal digital elements with smaller volume to monitor the environment in connected greenhouse by wireless sensor network.  They uses 433MHz ASK modulation radio signal to transfer data from front sensors.ASK  The nodes uses the superheterodyne receiver with the same frequency to gather data and then transfer data to the upper computer by GPRS.  According to above, the whole system can be used almost anywhere.

System Structure (Cont ’ d)  The wireless sensor module is consisted of : Low-power consumption MCU Data acquisition circuit Radio circuit Power system

System Structure (Cont ’ d)  The low-power MSP430F149, MSP series MCU is 1.8v~ 3.6v working condition, and the power consumption is decided by the working mode. Five low power working modes can be selected.  By controlling the pins working mode, the batteries can be used for longer time.  In terminal systems, MSP430 can complete A/D, data saving, coding, and other control work.

System Structure (Cont ’ d)  Considering the environment monitoring based on light, temperature, and soil humidity in a greenhouse, they uses light- sensitive diode, temperature diode, and soil humidity sensor to detect illumination intensity, air temperature, and soil humidity, respectively.  All the signals can be connected to MSP430 MCU A/D pins.  The data are converted and coded for transferring to the nodes by the radio signal.

System Structure (Cont ’ d)  They use the time sharing protocol which is a base of data transmission of the system.  The MCUs in the nodes and terminals can control sharing time period to transfer and receive data.

System Structure (Cont ’ d)  The radio circuit can work in UHF wave band, and 433MHz can be used freely.UHF Because the 433MHz radio transmitter can use built-in antenna and only one direction transmission circuit, the whole volume can be designed smaller and easily built in a small box.  433MHz ASK mode signal can reach 100 to 400 meters.

System Structure (Cont ’ d)  The node is consisted of Radio data receiver Embedded software system GPRS model ARM MCU Power Antenna

System Structure (Cont ’ d)  Radio data receiver is a demodulating circuit.  This signal can be amplified and demodulated, and then output data.  By using RX3310A, receiver sensitivity can be -100~102dbm.

System Structure (Cont ’ d)  RX3310A is an integrated circuit produced by Taiwan Hmark Company.  It is designed specially for ASK remote control, data transmission, and data receiving.  It is consisted of Low-noise and high-frequency amplifier Frequency mixer Local oscillator Intermediate frequency amplifier Intermediate filter and comparer  Its working frequency is MHz and maximum rate of data transmission is 9.6Kbps.

System Structure (Cont ’ d)  The monitor device of this system is consisted of PC Receiving module  PC fulfils the main data processing and display tasks.  It can receive the data from the nodes to analyze the situation and then transmit the instructions to the related devices, such as Sun visors Lights Temperature devices spraying pumps  Receiving module is consist of GPRS with TCP/IP, and the received data is transferred to PC from RS232.

Software

 Wireless sensor terminal software can be divided into data receiving, encoding, and transmission.  MSP430 can realize super low power consumption in Working and Stand-by mode, so the software design must consider about reducing power consumption.

Software (cont ’ d)  Sensor terminal work flow Transmission ↙

Software (cont ’ d)  The monitoring software is designed by LabVIEW.  It can be used conveniently in controlling and programming.  The powerful display function can be used in displaying graphs (especially on tendency chart) and processing data.

Software (cont ’ d)  Monitor system work flow Send ← ↘ Receive

Conclusion

 They use MSP430 MCU sensor terminal design and reduces system working power.  Two button batteries can monitor for 2 years by recording 20 times per day and 0.4 sec per time.  Using MSP430 MCU chip kernel circuit covered with thick film, the volume is similar to the size of 9V battery.  The production cost can be limited in tens of Yuan.

In my opinion  Terrible English. Ex: Ex: … Ex:  Unclear and incomplete content. Ex: No concrete experimental results.  Poor structure. Sneed in ? ??

ASK (Amplitude-shift keying)  ASK is a form of modulation that represents digital data as variations in the amplitude of a carrier wave.

UHF (Ultra high frequency)  Ultra high frequency (UHF) designates a range (band) of electromagnetic waves with frequencies between 300 MHz and 3 GHz.

Comment Report  Summary of contribution (shown to the authors) The authors applied wireless sensor networks to real agricultural environments. They considered volume, lifetime, and producing cost of the sensors when designing their system.  Detailed comments (shown to the authors) There is too many syntactic and spelling errors in this paper. Some content of this article is incomplete. The structure of this article can be rearranged clearer. There is no investigation into related works, so there is no evidence for telling the audience that this paper really provides a new solution or application in this area. Besides, there is also no other work to be compared with the solution proposed by this paper.  Candidate for the best paper No.  Final score (form 1 to 5) 1 → Reject !