waterwell online water quality management - csd fall 2008 waterwell solution online water quality...

WaterWell Online Water Quality Management - CSD Fall 2008

WaterWell SolutionOnline Water Quality Managementhttp://www.tslab.ssvl.kth.se/csd/projects/0821006


1.

STATEMENT

PROBLEM


Blantyre,Malawi


Technology vs. Problem

K.O

• WSN• Sensors• Sun SPOTs• Solar Panel

• Automation• Accurate Results

• Wide-Area• Power Source


PreviousWork


2.

CONTRIBUTION

UNIQUE


Reading Serial Data


Testing The Connection

• Two Java Programs (NetBeans)– To read data from sensor

through serial port, forward to base station and vice versa

– To switch on & off the level converter (Sensor) through H0 pin


Real-Life


Consumption3. POWER


WaterWell System

Host Station• Send HELLO• Synchronization• Configuration• Gathering data

WSN Node

• Reading data from

sensor

• Sending data to base

station


How does it work ?


System Diagrams

Sequence Diagram State Transition Diagram


Power Consumption Issues

• Problems:• Sustainability• Sensors’ Power

• Solutions:• Solar Panel• Wake Up Mechanism• Power Adjustment


Wake-Up Mechanism

Wake-up Mechanism

Sensor


Link Quality Experiment

• PRR: Packet Received Ratio The real link quality• Parameters: LQI: Link Quality Indicator RSSI: Received Signal Strength Indication CORR: Correlation• Which one is the best?• How many samples?


Experiment Set-up

Sender Receiver

1000 packets (1, 40, 80, 120 bytes)

-31dBm

100 different distances


LQI ResultsPRR grows with LQI increases


SAMPLES15 Samples: tradeoff between network overhead and LQI accuracy


CONCLUSION

• Use LQI

• Use min. 15 Samples

Power Experiment

Sender Receiver

500 packets(containing output power value)

-32 to 31 dBm

7 different distances

OUTPUT POWERvs LQI

LQI 200

-25 dbm

-24 dbm

POWER ADJUSTMENT

• Base station helps

SunSPOT to adjust

output power

• Speed up negotiation:

– Adjust power between 22

power steps

– Dichotomy


Aspect4. Busines

s


BUSINESSAssessment Report

B


Nästa:Implementation

Investigation

Marco’s Tasks

Design Documents

T

Solar Panel

Business Opportunities

Implementation

Final Reports

Testing


30 Second Summary

• WSN offers many possibilities• Sun SPOT Rocks !• LQI is the best !• Min. 15 Samples• Deep Sleep Mode• Everything is under control


WaterWell SolutionQuestions and Answers