Plan for WSN of Smart Irrigation Project

Overview:

This document describes the wireless sensing prototype system that will be delivered in 2016.

The short and long-term goals：

• a. Establish the communication between sensors and control system.
• b. Establish the communication between control system and the base.

Main Hardwares:

• The nodes: Campbell Scientific CWS 655 (price: xxxxxxx)

It is a kind of cable-free sensor, which has 12 cm roads and monitors soil volumetric water content, bulk electrical conductivity, and temperature.

• The Sensor Base: Campbell Scientific CWB100 and CR1000 (price: xxxxxxx)

CWB100 is the master radio in a Campbell Scientific wireless-sensor network It polls and stores data from up to 50 wireless sensors, and then passed that data to a datalogger.

The CR1000 is a kind of datalogger. It consists of a measurement and control module and a wiring panel. It measures sensors, drives direct communications and telecommunications, reduces data, controls external devices, and stores data and programs in on-board, non-volatile storage.

Tutorial for installing:

Tutorial 1

Tutorial 2

Tutorial 3

Tutorial 4

Tutorial 5

Tutorial 6

Tutorial 7

Tutorial 8

Tutorial 9

Tutorial 10

Tutorial 11

The problem set and decision making:

• 1.How to implement communication between the datalogger and our control system

a.(if the control system is just an ARDUINO) we can connect with ARDUINO through serial port b.(if the control system is just a PC) we can connect our datalogger to the PC through USB c.or we can get access to our LAN and transfer data to our Base. The control system can communicate with the Base.

• 2.How to establish the communication between the datalogger and the base (white house)

We can set up our own local area network. To implement this we choose WiFi technology based on IEEE 802.11 standard. We need a base station to implement communication covering several kilometers distance. We can choose WBS510, 5GHz 300Mbps Outdoor Wireless Base Station, the product from TP-Link company. Also, we can power the base station through Passive Power over Ethernet (PoE, 16-27VDC), putting them on the towers.

• 3.Why we choose WiFi to implement our communication with Base(white house)

I would not say this is the only method we can try, but at this moment the WiFi is a good choice in terms of complexity, cost, communication features.WiMAX is expensive. Also, Bluetooth and ZigBee are not capable for long distance range.

• 4.Why do we need datalogger?

I wouldn’t say that we have to use this. However, this is a good choice from my point of view, because the datalogger can provide me the methods to manage and communicate with sensors, and also it provides a lot of ports to connect with different device. It is very time-consuming that we build up everything from zero.

• 5.How many sensors do we need?

It depends on the how large the experiment site is and the coverage of one sensor. At this moment, I only need one to test the whole communication system.