Design And Implementation Of Data Collection And Control Nodes For The Prevention And Control System Of Grape Downy Mildew

Grape downy mildew seriously effects grape yield,this paper based on ZigBee wireless sensor network technology,using CC2530F256 chip as the core control chip to design and achieve grape downy mildew data collection and control system based on IEEE 802.15.4 protocol,this system has low power consumption,multiple nodes,more convenient,and can long distance communication.The system was based on the Z-Stack protocol stack,and using ZigBee wireless communication technology,ad hoc networks technology,multi thread control technology,and PWM pulse width modulation technology,and so on.Through the tree network topology to make collection nodes,routing nodes,control nodes,and sink node together,cooperative awareness,achieve communication and transfer of data and information.By destroy necessary conditions of downy mildew to achieve downy mildew prevention and control effect.The main contents of this paper include:(1)Collection nodes used AM2306 as the sensor device to collect temperature and humidity in grape environmental,and used GY-30 as the sensor device to collect light intensity in grape environmental.Collection nodes take low power energy saving strategy,on the one hand,package for collected data and send to sink node by point to point wireless transmission through the ZigBee network,on the other hand,display related data in the OLED color screen.(2)Control node is composed of a mechanical link transmission device and electronic control part,waiting for the wireless command received from sink nodes and to start light.Once received command,control node would trigger two relay on,STC89C52 microcontroller through PWM square wave pulse signal to control the speed and direction of the 57 two-phase four wire stepper motor,in the motor function,through the reasonable design of mechanical link transmission device,can automatic control lighter device to rotary lighting.(3)Sink node analysis and judgment for the received data packet,and through the friendly interface of PC software to real-time display relevant data and image chart.Once the relative humidity beyond to 90%,and meanwhile light intensity less 10 Lx,that is reach to the grape downy mildew threshold condition,through the network Short address to find the nearest short address of control node device ID,transfer light command by means of point to point or through routing nodes in single hop or multi hop to notice relative control node start work.(4)The system install and test.The system is installed in the field,joint debugging and the system testing.Results show,in the transmitting power is-16 dBm case,stable communication distance is 70 meters in grape Greenhouse,collection nodes use 4.5V dry battery as power,control nodes by rotating light can cover an area of 80 square meters,compare with fixed light mode,one control node can replace 8 control nodes and 16 lighting devices,greatly reduces the test cost and power consumption.Compared with the similar greenhouse without installed system,grape plant significantly has less white spots,and grape fruit grow well,confirmed that the system can effectively prevent and control of grape downy mildew occurrence and spread.