Transcript Networked Weather Station (EE 4391 Group 2.3)

Networked Weather Station
(EE 4391 Group 2.3)
Senior Design Project Team
Dean Thomasson, Stephen Frank, & Nick Speir
Sponsored by:
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.
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
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).
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).
Design Details (Network Diagram)
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
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
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).
Design Details (Hardware)
Freescale’s Kinetis KW2x MCU Radio Transmitter Board is
programed to read in the sensors using Freescale’s Kinetis SDK
and IAR
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.
Design Details (Software)
The 802.15.4 standard defines the physical layer (PHY) and
media access control (MAC) layer
Design Details (Software)
The physical layer defines frequency, power, modulation, and
other wireless conditions of the link.
Design Details (Software)
The MAC layer defines the format of the data handling.
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.
Design Details (Software)
● Implementing Thread in our project:
Design Details (Software)
The first thing that happens is the Thread gateway router sends
out a request for sensor values.
Design Details (Software)
Upon hearing the request the Transmitter board will read in the
requested sensor values.
Design Details (Software)
The transmitter board then responds to the Thread gateway
router with the requested values.
Design Details (Software)
The sensor values are then sent over the internet to the
Proximetry database where they are stored.
Design Details (Software)
Real-time weather station data can be accessed from any
browser via Proximetry’s Web UI.
Design Details (Validation Testing)
● Individual Sensor Verification
● Data Transmission Verification
● Completed Design Verification
Bill of Material (Prototyping)
Freescale Parts:
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Tower KL46Z Microprocessor Board
Tower Elevators
Tower Analog to Digital Converter Board
Kinetis KW2x MCU Radio Board
Tower Prototyping Board
Freescale Barometric Pressure Sensor
Total:
$150
$80
$120
$150
$15
$15
$530
Non-Freescale Parts:
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Wind Speed/Direction & Rain Sensor
Light Sensor
Temperature Sensor
Enclosure
Unistrut Mounting Frame
Total:
$70
$7
$2
$50
$88
$217
Bill of Material (Production)
Freescale Parts:
● Kinetis KW2x MCU Radio Board
● Freescale Barometric Pressure Sensor
Total:
$150
$15
$165
Non-Freescale Parts:
●
●
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Wind Speed/Direction & Rain Sensor
Light Sensor
Temperature Sensor
Enclosure
Total:
$70
$7
$2
$50
$129
Budget Review
Freescale Budget for non-Freescale parts:
Freescale Budget Spent to Date:
$200
$129
University Budget:
University Budget Spent to date:
Undefined
$88
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 doesn’t fog up or collect dirt easily.
● Automated assembly could be costly.
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.
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.
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.
Summary
● The Networked Weather Station provides a means for
remotely monitoring various weather sensors.
● This is accomplished via a Thread network using Freescale’s
Kinetis KW2x MCU Radio Board and gateway router.
● Real-time data can be accessed from any browser via
Proximetry’s Web UI.
● The production cost of a fully assembled weather station with
wireless transmitter is expected to be less than $300.