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

MicrocontrollerArduinoRuns programmed code to send and receive data on mesh networkWireless ShieldXbee Provides easy form of adapter from transceiver to arduino due to header misalignment.

Transceiver and Antenna

TransceiverXbee-PRO digimesh 900Provides mesh protocolTransmits data to other node

Antenna7" ½ wave dipole, bulkhead mount, RPSMA connectorOmni-directional transmission of data

Wind SensorsWind Vane NRG#200P Provides wind direction Angle from North=(360’/Vin)*VoutVout ranging from 0 to Vin

AnemometerNRG#40CProvides wind speedGenerates 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 4012345678

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

Latency (ms)

Latency (ms)

Linear (Latency (ms))

Number of Nodes

Tim

e (m

s)

2 nodes 3 nodes 4 nodes2.9ms 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◦ BarometersThis 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