Transcript 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
Signal
Converter
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
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 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
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.

Scout Tower Code

Reads the Voltage
Signal at selected
pins of the Arduino

Aggregates data at a
user specified
interval
Anemometer
Output Signal
Measures Pulse
Width
Converts Pulse
Width to Wind
Speed
Sends Wind
Speed to Serial
Port

Central transceiver code

Receives data from all
Reads Signal
From
Transceivers
other nodes in the mesh
network

Aggregates all of the data

Prints new data set to a
text file
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

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.

We connected the
anemometer directly
to an oscilloscope

Signal amplitude and
frequency increases
as wind speed
increases

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

Able to obtain a sine
wave from the
anemometer

Outputs a square wave
with a frequency
relative to the actual
wind speed

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

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

Found optimal
frequency of our
antennas to be
marker 1

Freq= 896.247MHz
marker 1
freq=896.2473 MHz
dB(S(1,1))=13.97
marker 2
freq=1.8014 GHz
dB(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.

Tested North of
Ames on a flat gravel
road

Achieved an
approximate range
of 1.75Km

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

Placement of four nodes at a
Node 1
certain distance preventing
direct communication
between first and last node

Upon the removal of a middle
Node 2
Node 3
node from the system the
line of communication is not
broken
Receiving Node
User

128-bit encryption is incorporated in the
protocol for the transceivers

Client required only verification of encryption
setting in transceivers

Node 1 sends current time to node 2

Node 2 computes difference from it’s current
time
Time
Synchronized
Time
Synchronized
Node 1
Node 2
Latency (ms)
8
y = 2.1x + 0.9333
7
R² = 0.9881
Time (ms)
6
5
Latency (ms)
4
3
2
Linear (Latency
1
(ms))
0
2
3
4
Number of Nodes
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

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

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.
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

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
Any Questions?