Transcript Stand-Alone and Mesh Networks of Dissolved Oxygen (DO) Monitors

Stand-Alone and Mesh
Networks of Dissolved
Oxygen (DO) Monitors
Sd-May11-20
Betty Nguyen
Scott Mertz
David Hansen
Ashley Polkinghorn
Advisors
Joseph Shinar
Ruth Shinar
with
Bob Mayer
Alex Smith
Background
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Applications
Waste water treatment
 Chemical plants
 Fish farms
 Fermentation lab
 Monitoring water quality
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Saves energy
Market Research
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Existing solutions: > $1000
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HACH LDO Process Dissolved Oxygen Probe
$1565
No remote capabilities
Market: over 100 M
Project Objective
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Existing monitors and network
Account for temperature variation
Temperature sensor
 DO level calculation modification
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Ensure functioning mesh network
Test integrated units
 Make necessary changes
 Add new functionality
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Conceptual Sketch
Functional Requirements
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Required
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The monitor units shall take readings of dissolved oxygen.
The monitor units shall wirelessly transmit their readings to the master
controller.
The master controller shall request readings from each monitor unit.
The master controller should have a graphical user interface to display
measurements.
The master controller user interface shall allow the user to poll a monitor
unit for data.
The system shall query each monitor unit for data through the master
controller.
The Windows service shall log all data processed through the unit in a
SQL database.
The network nodes shall create a star-like topology
Optional
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The network nodes shall create mesh network topology
The master controller shall send calibration data to each monitor unit.
Non-functional Requirements
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The system shall have an optimal operating
range of 1000 meters.
The microcontroller shall enter a sleep state
between samples.
A temperature probe shall be attached to the
existing sensor probe to increase calculated
accuracy.
Constraints
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Operating temperature: 0 to 50° Celsius. The
temperature sensor must be accurate to ±1°C to satisfy
this constraint. DO Monitor units need to be resistant
to changes in temperature.
Operating environment: water resistant. The probe
should be resistant to water damage.
Battery power is limited in sensor locations. The system
needs to conserve as much power as possible when not
measuring DO levels to ensure long battery life.
Existing implementation uses Zigbee. Zigbee modules
cannot route while in sleep mode.
Risks
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Circuit board redesign
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Encountering circuit issues frequently
Existing design problems
Sleep prevents mesh network from functioning
 Power is controlled by DO Monitor, not ZigBee
node
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Functional Decomposition
DO Monitor
Zigbee Node
Hardware Platforms
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AtxMega128
ZigBit Amp
Custom DO Sensor
Temperature Sensor: Temperature-to-Voltage
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TC1047
Test Plan: DO Sensor
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Temperature sensor
Verify voltage levels from temperature sensor.
 Verify ADC conversion.
 Verify temperature constraint extremes.
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DO Sensor
Verify DO sensor readings at room temperature.
 Verify DO sensor readings at various temperatures.
 Verify device enters and exits sleep mode
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Test Plan: ZigBee Node
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Verify the ability of a ZigBee Node to receive a
message.
Verify the ability of a ZigBee Node to transmit a
message.
Test Plan: NW Coordinator; Master
Controller
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Network Coordinator
Verify the ability of a Network Coordinator to
receive a message.
 Verify the ability of a Network Coordinator to
transmit a message.
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Master Controller
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Verify the ability of the Master Controller to send a
command.
Test Plan: Integration Testing
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Verify communication between the Master Controller (PC) and
Network Coordinator.
Verify transmission of a command from the Network
Coordinator to all ZigBee Nodes by verifying that the same
command is read on all ZigBee Nodes. This is part of the star
topology.
Verify transmission of data from any ZigBee Node to the
Network Coordinator by verifying the same data was received by
the Network Coordinator. This is also a part of the star
topology.
[Optional] Verify a ZigBee Node is able to receive data from
another ZigBee Node and able to pass it to the Network
Coordinator. This makes a mesh network.
Repeat steps 1 - 4 with all command types.
Test Plan: System Testing
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Verify power usage when in OFF state.
Verify the device enters sleep mode when not in use.
Confirm the user interaction of pressing the “Take
Sample Now” button in GUI will result in new
measurement data from all DO monitor units.
Confirm the user interaction ability to reconfigure
coefficient calibrations on all DO monitor units.
Accomplishments
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Temperature sensor tested in hardware
Hardware debugging
Obtained necessary software stacks
Some network testing
Documentation clarified and expanded
Project Status
Milestone
Temperature HW
Complete
Design Document
Complete
Temperature SW
Complete
Mesh Network
Functional
Sleep Mode functional
Mesh Network
Temperature
Calibration Expansion
complete
Description
The temperature sensor will be integrated with the DO Monitor.
X
Design document will be completed.
X
Temperature readings should be accurate to ±1°C. DO readings should
be adjusted using the coefficients for the correct temperature range.
The mesh network has been confirmed to be functional, and all errors
have been corrected.
The unit has been confirmed to enter sleep mode, and it enters a
decreased power use state.
New values for temperature coefficients can be sent over the mesh
network from the GUI to individual monitors, and the monitors can
replace their coefficient tables.
Schedule
Resource Estimate
Name
Voltage Regulator
Diodes
Temperature Probes
ATXMega
LED Drivers
Digital Supplies
Zigbits
LCD
Other Parts
Total
Price
$ 10.00
$
6.00
$ 6.00
$ 40.00
$
8.00
$ 10.00
$ 100.00
$ 20.00
$ 20.00
$ 220.00
Member Contributions
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David Hansen
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Scott Mertz
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Hardware debugging
Temperature sensor testing
Betty Nguyen
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Extensive hardware critiquing and debugging
Network testing
Setting up test framework
Ashley Polkinghorn
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Network testing
Setting up test framework
Next Semester…
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Building and testing two more boards
Make Master Controller consistent with sleep
mode design
Possibly implement remote calibration
Finish testing network components
Finish implementing and testing temperature
firmware
Integration testing