Networked Weather Station

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Networked Weather Station
(EE 4391 Group 2.3)

• Senior Design Project Team
• Dean Thomasson, Stephen Frank, Nick Speir

Sponsored by
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Background Information (IoT)

• Internet of Things (IoT)
• The IoT allows us to network physical everyday
  objects with embedded electronics and software to
  achieve a greater value and service through
  exchanging data and operation control.
• Freescale wants to become more familiar with how
  best to integrate their hardware into the IoT
  marketplace.

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Design Details (Goals)

• Construct a weather station that communicates
  over a Thread (IEEE 802.15.4) network
• Collect inputs from various weather sensors.
• Aggregate, package and transmit the collected
  values.
• Store the final data in a central database.
• The final design should focus on
• Low energy (low power consumption) remote nodes.
• Small size and low cost.
• Final design reports to be submitted to Freescale
  to be used as reference design material or as
  application notes

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Design Details (Stretch Goals)

• Display data from the database using analytical
  graphing software.
• Analyze the effects of loading the ZigBee network
  with a lot of sensors and traffic.
• Provide remote power source for the weather
  station (i.e. solar panels or batteries).

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Design Details (Project Scope)

• Students Responsible for the weather station
  itself, which includes reading in sensor values
  onto the Kinetis KW2x MCU radio board and then
  transmitting those values over the Thread
  network.
• Freescale Responsible for configuring the
  Thread stack and central gateway router to
  request sensor data from the weather station and
  then pass along that data to Proximetry over the
  internet.
• Proximetry Responsible for receiving the data
  from the central Thread gateway router, storing
  the data, and providing access to visualize the
  data via a Web User Interface (Web UI).

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Design Details (Network Diagram)
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Design Details (Hardware)

• Minimum Accuracy/Resolution of Weather Sensors
• 1 kPa for pressure
• 0.5 C for temperature
• 0.011 inches for rain fall
• 1 MPH for wind speed
• 22.5 degrees for wind direction
• 10 µW/cm2 for irradiance

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Design Details (Hardware)

• Temperature Sensor
• -40 C to 125 C Range
• Freescale Barometric Pressure Sensor
• 50 to 115 kPa, Absolute
• Wind Speed/Direction and Rain Sensor
• Rain Gauge Self-Tipping Bucket, 0.011 inch
  increments
• Anemometer Cup Type 1.492 MPH 1 pulse per
  second
• Wind Vane Eight resistance type sensors, 22.5
  increments
• Light Sensor
• Contains both infrared and full spectrum diodes
• Extremely wide dynamic range 1 to 600,000,000
  Counts
• Temperature range -30 to 80 C

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Design Details (Hardware)

• Possible Future Upgrades
• Better sensors such as a PAR (Photosynthetically
  Active Radiation) sensor, which measures
  photosynthetic light levels in both air and
  water.
• Provide remote power source for the weather
  station (i.e. solar panels or batteries).

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Design Details (Hardware)

• Freescales Kinetis KW2x MCU Radio Transmitter
  Board is programed to read in the sensors using
  Freescales Kinetis SDK and IAR

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Design Details (Software)

• The transmission of sensor values uses Thread, an
  IPv6 based protocol for smart home devices,
  which is built on top of the IEEE standard
  802.15.4 for low rate WPAN.

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Design Details (Software)

• The 802.15.4 standard defines the physical layer
  (PHY) and media access control (MAC) layer

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Design Details (Software)

• The physical layer defines frequency, power,
  modulation, and other wireless conditions of the
  link.

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Design Details (Software)

• The MAC layer defines the format of the data
  handling.

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Design Details (Software)

• Thread provides enhancements to the network and
  transport layers such as authentication,
  encryption, and a data routing capabilities like
  the self-healing mesh network.

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Design Details (Software)

• Implementing Thread in our project

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Design Details (Software)

• The first thing that happens is the Thread
  gateway router sends out a request for sensor
  values.

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Design Details (Software)

• Upon hearing the request the Transmitter board
  will read in the requested sensor values.

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Design Details (Software)

• The transmitter board then responds to the Thread
  gateway router with the requested values.

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Design Details (Software)

• The sensor values are then sent over the internet
  to the Proximetry database where they are stored.

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Design Details (Software)

• Real-time weather station data can be accessed
  from any browser via Proximetrys Web UI.

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Design Details (Validation Testing)

• Individual Sensor Verification
• Data Transmission Verification
• Completed Design Verification

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Bill of Material (Prototyping)

• Freescale Parts
• Tower KL46Z Microprocessor Board 150
• Tower Elevators 80
• Tower Analog to Digital Converter Board 120
• Kinetis KW2x MCU Radio Board 150
• Tower Prototyping Board 15
• Freescale Barometric Pressure Sensor 15
• Total 530
• Non-Freescale Parts
• Wind Speed/Direction Rain Sensor 70
• Light Sensor 7
• Temperature Sensor 2
• Enclosure 50
• Unistrut Mounting Frame 88
• Total 217

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Bill of Material (Production)

• Freescale Parts
• Kinetis KW2x MCU Radio Board 150
• Freescale Barometric Pressure Sensor 15
• Total 165
• Non-Freescale Parts
• Wind Speed/Direction Rain Sensor 70
• Light Sensor 7
• Temperature Sensor 2
• Enclosure 50
• Total 129

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Budget Review

• Freescale Budget for non-Freescale parts 200
• Freescale Budget Spent to Date 129
• University Budget Undefined
• University Budget Spent to date 88

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Manufacturability Issues

• Need for Custom connector
• A custom connector must be manufactured to
  connect the weather sensors in the production
  model. This could increase production costs and
  lead times slightly.
• Translucent Material Needed
• The light sensor housing needs to be a highly
  transparent material that doesnt fog up or
  collect dirt easily.
• Automated assembly could be costly.

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Societal Impact

• The Internet of Things (IoT) has the potential to
• change the way we interact with the world around
  us.
• The networking protocol, Thread, is already being
  used by connected thermostats and other home
  automation applications.
• With all of these devices connected to the
  internet they are opened up to remote access and
  automation.
• This level of connectivity has the potential to
  greatly increase the usefulness and benefit that
  we normally receive from everyday devices.

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Environmental Impact

• The weather station has a relatively low
  environmental impact.
• All of the materials used in its construction can
  be recycled by conventional means, such as with
  the plastic enclosure or metal mounting frame, or
  through an electronics recycling facility for
  silicon devices.
• Its low power consumption provides for efficient
  operational costs both economically and
  environmentally.

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Ethical Responsibility

• Security
• To protect the security of data and intellectual
  property
• all documentation and software was accessed by
  machines which were password protected. Or if
  this was not possible (like on the Kinetis KW2x
  MCU radio board) it was kept locked up when not
  in use.
• Access was limited to only those who were
  directly involved in the project.
• Safety
• Best practices for electrical safety were used
  when constructing the weather station to ensure
  the safety of all those who may come in contact
  with it.

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Summary

• The Networked Weather Station provides a means
  for remotely monitoring various weather sensors.
• This is accomplished via a Thread network using
  Freescales Kinetis KW2x MCU Radio Board and
  gateway router.
• Real-time data can be accessed from any browser
  via Proximetrys Web UI.
• The production cost of a fully assembled weather
  station with wireless transmitter is expected to
  be less than 300.