Ridgeline Meteorological Sensor Network

Stephen Copeland, Xau Moua, Joseph Lane, Robert Akerson

Client: Doug Taylor, John Deere Renewables

Advisors: Dr. Manimaran Govindarasu, Dr.Venkataramana Ajjarapu

Small scout towers capable of wirelessly transmitting measurements to large MET towers.

Wireless communication via radio transceivers on scout tower and MET tower.

Built-in mesh networking protocol

Project Plan

Design Scope

Signal Converter

Microcontroller and Wireless Shield

Microcontroller

Arduino

Runs programmed code to

send and receive data on

mesh network

Wireless Shield

Xbee

Provides easy form of adapter

from transceiver to arduino

due to header misalignment.

Transceiver and Antenna

Transceiver

Xbee-PRO digimesh 900

Provides mesh protocol

Transmits data to other node

Antenna

7" ½ wave dipole, bulkhead

mount, RPSMA connector

Omni-directional

transmission of data

Wind SensorsWind Vane

NRG#200P

Provides wind direction

Angle from North=(360’/Vin)*Vout

Vout ranging from 0 to Vin

Anemometer

NRG#40C

Provides wind speed

Generates a sine wave whose

frequency determines wind speed

Sensor Circuitry

Used to transform the Sine

wave output from the

Anemometer into a square

wave which provides the

arduino with a frequency that

represents the measured wind

speed.

Sensor Circuitry Cont.

Scout Tower Code

Reads the Voltage

Signal at selected

pins of the Arduino

Aggregates data at

a user specified

interval

Arduino CodeAnemometer Output Signal

Measures Pulse Width

Converts Pulse Width to Wind

Speed

Sends Wind Speed to Serial

Port

Central transceiver code

Receives data from all

other nodes in the mesh

network

Aggregates all of the data

Prints new data set to a

text file

Arduino Code cont.

Reads Signal From

Transceivers

Sends Data To Computer

Averages Wind Speed Data

Sensor Testing PCB Functionality Testing Range Evaluations

◦ Elevated testing locations north of Ames Power consumption

◦ Use of multi meters to measure current and voltage levels

Microcontroller◦ Basic data communication

Testing

Self Healing◦ Selected modules turned off during transmission

Security◦ Encryption of data being transmitted

Latency◦ Receiving rate vs. data size

Casing◦ Shock, vibration, realistic impact, and contact

with water, ice, and snow.

Further Testing

We connected the

anemometer

directly to an

oscilloscope

Signal amplitude

and frequency

increases as wind

speed increases

Sensor Testing Anemometer Results

We connected the wind

vane to 5V power supply

Oscilloscope gives

output voltage over time

Voltage varies as wind

vane changes direction

from 0 to 360 degrees

Sensor Testing Wind Vane Results

Able to obtain a sine

wave from the

anemometer

Outputs a square

wave with a

frequency relative to

the actual wind speed

PCB Functionality Testing and Anemometer Results

Wind speed in mph

Top node 1

Middle node 2

Both sampled and

averaged every 10

seconds

Bottom average of node

1 and 2 calculated every

10 seconds

Aggregated Data Simulation

Successful interfacing

to the sensors and PCB

for gathering of data

Aggregation of data

from sensors

Storage of data as MPH

in a text file from

output

Microcontroller Results

Found optimal

frequency of our

antennas to be

marker 1

Freq= 896.247MHz

Antenna Results

marker 1freq=896.2473 MHzdB(S(1,1))=13.97

marker 2freq=1.8014 GHzdB(S(1,1))=13.66

We attached sensors to the roof

of Coover Hall.

Successful transmission of data

to motors lab from two nodes on

roof

Simulated rugged terrain at

Veenker golf course north of

campus

Achieved an approximate range

of 0.8 Km between nodes.

Results for Rough Terrain Testing

Tested North of

Ames on a flat

gravel road

Achieved an

approximate range

of 1.75Km

Results for Range Testing

We spliced the USB cable

between the device and

PC

Connected inner USB

wiring to a multi meter

Through the use of P=I*V

we determined the

required power to be

around 0.5 Watts

Power Consumption Results

Placement of four nodes at a

certain distance preventing

direct communication

between first and last node

Upon the removal of a

middle node from the system

the line of communication is

not broken

Self Healing Results

Receiving Node

Node 1

Node 3

Node 2

User

128-bit encryption is incorporated in the

protocol for the transceivers

Client required only verification of

encryption setting in transceivers

Security and Latency Results

Node 1 sends current time to node 2

Node 2 computes difference from it’s

current time

Security and Latency Results

Time Synchronized

Time Synchronized

Node 1 Node 2

Security and Latency Results

2 3 40

1

2

3

4

5

6

7

8

f(x) = 2.1 x + 0.933333333333335R² = 0.988050784167289

Latency (ms)

Latency (ms)

Linear (Latency (ms))

Number of Nodes

Tim

e (

ms)

2 nodes 3 nodes 4 nodes

2.9ms 5.4ms 7.1ms

Remained water tight

under running water

Absorbed force from

hammer without

damage to the inner

components

Withstood 6℉ without

damage

Case Testing Results

Consists of sections of

PVC and Brass

connectors to ensure

stability for the sensors

Nema-4 enclosure

Clamped to vent pipes

on the roof of Coover

Hall

Mounting System

Cost of Product

Task Breakdown

Fall Semester Project Schedule

Utilizes aggregated wind speed from the

roof of Coover

USB interface with transceiver and Desktop

PC

Uses Labview Software to run motor

Motor is coupled to a wind turbine which

simulates wind power generation.

EE 491 Wind Turbine Project

EE491 Wind Turbine Project cont.

http://seniord.ece.iastate.edu/may1101

Use of renewable energy power source (wind or solar)

Integration of CFD into calculations for Wind Turbine

project

Addition of more sensors to device

◦ GPS units

◦ Temperature Sensors

◦ Barometers

This would allow for better analysis of potential wind

generation locations

Recommendations

Leland Harker, ISU Parts Shop

Senior Design Team SD MAY11-01

Doug Taylor, John Deere

Brad Luhrs & Bryan Burkhardt , DMACC

Dr. Manimaran Govindarasu

Dr. Venkataramana Ajjarapu

Acknowledgements

Any Questions?

Thank You