Weather Tracker

1
Weather Tracker

• Ben Yoder (Project Leader)
• Vaibhav Sahgal
• Taylan Big

2
Overview Specifications

• Weather Tracker aims to collect weather
  information via sensors and display this
  information on a stand alone console with the use
  of a microcontroller.
• This project attempts to provide students useful
  educational information about the elements of
  weather and how they are measured.

3
Overview Specifications

• The weather information that will be collected
  consists of
• Temperature
• Relative humidity
• Wind speed direction
• Air pressure
• Rainfall

4
Researched Design Approaches

• Possible design were approaches researched
• Using a PC to collect and display data
• Purchasing a weather tracker and uploading data
  to the internet
• Using a microcontroller and a set of sensors to
  collect and display data

5
Initial Concept

• Using a PC to collect and display data

Display at KES
Weather Sensors
USB/Serial
PC
Internet
Weather Tracker logger Software (JAVA/VC)
6
Design Flaws/limitations

• Having a special PC for the station might be
  wasting of resources
• PC would be too big to leave in a central
  position
• Project partners would not want a external PC on
  the network
• Sensors that connect directly to a computer are
  hard to find and expensive

7
Alternative Solution

• Purchasing a weather tracker and uploading data
  to the internet

8
Design flaws/limitations

• A separate weather station would not be as
  visible to the kids (location limitations)
• KES at this point wanted a non-networked stand
  alone project.

9
Final Design Solution

• Using a microcontroller and a set of sensors to
  collect and display data

10
Design Decisions

• From the possible designs, the microcontroller
  solution was chosen.
• Stand alone non-networked
• No resources wasted
• Compact
• Will be specific to this project and unique
• A lot of components available
• A prototype can be built and improved.

11
Design Decisions

• What data are we collecting and how specific do
  we want to be?
• After contacting Ray Polstra, it was decided that
  weather information collected could be narrowed
  down to
• Temperature
• Relative Humidity
• Wind Speed Direction
• Air pressure
• Rain fall
• What can this data be used to calculate?

12
Algorithm design and data processing
13
Temperature

• Temperature is to be measured at multiple
  locations and recorded at given intervals in a
  day.
• From these measurements high, low and average
  temperature can be determined.
• These values can then be compared to historical
  averages for that month.

14
Algorithm design for data collection and storage
for temperature
For this algorithm design, assumed unit of time
is minutes. ti Chosen time interval
(minutes) tc Current time of system
(minutes) Size 1440 / ti 1 (where 1440 is
minutes in a day) TnSSize Storage for
temperature values from sensor n. TH High
temperature value (Fahrenheit) TL Low
temperature value (Fahrenheit) Tmean Average
temperature (Fahrenheit)
Initialize TnS
tc ti0
y
Store T
n
Update TH,L,mean
tc1440
y
Following is the detailed flowchart for how the
temperature measured can be processed to obtain
high low and average temperatures.
n
15
i0
TnStc/ti 1 Tn
TnSi NoVal
TL T1S0 TH T1S0 j 0 total 0
i
ilt1440/ti
y
totaln totaln TnSj
n
tc ti0
y
TLSjltTL THSjltTH
y
TL TLSj TH THSj
n
n
j
j lt tc/ti
y
tc1440
y
total / j Tmean
n
n
16
Relative Humidity, Wind Speed Direction,
Atmospheric Pressure, Rainfall

• Relative humidity, wind speed and wind direction,
  atmospheric pressure and rainfall can all be
  measured directly with appropriate sensors.
• Calculated average temperature and measured
  relative humidity can be used to calculate the
  heat index and the dew point.
• Calculated average temperature and measured wind
  speed can be used to calculate wind chill

17
Calculation of Heat Index Dew Point and Wind
Chill
Heat index can be calculated as shown above. The
result HI is in Fahrenheit. Dew point can be
calculated as shown on the left. The result Td is
given in Celcius. This value will be converted to
Fahrenheit. Wind Chill can be calculated using
the formula below. The result Twc is in Fahrenheit
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Values obtained after data processing
T1
T High
T2
Data processing
T Av.
Values obtained from sensors
T3
T Low
T4
Dew Point
Data processing
Relative Humidity
Heat Index
Wind Direction
Data processing
Wind Speed
Wind Chill
Air Pressure
Rainfall Av. Daily
Data processing
Rainfall
Rainfall Av. Monthly
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Timeline
20
Work in progress
Projected completion type
Task completed