SDMAY12-23

Stream Depth GaugeTeam: SDMAY 12-23Team MembersJohn HendersonCurt LaBargeGreg PearsonYixin QiaoClient/AdvisorSteve Holland(ISU Canoe and Kayak Club)1Project GoalDesign and build a low-cost stream depth gaugeThe gauge should be:Self containedRobust in the environmentLow maintenanceLow powerCapable of transmitting measurements wirelessly

SDMAY12-23

ProblemsIowa flow levels change dramaticallyCurrent gauging strategies are inadequate High MaintenanceAt threat of cancelationCover a limited amount of streams and riversCanoers and Kayakers need easy access to flow data to accurately plan tripsSome waterways are currently not monitored

Photo Credits: ISU Canoe and Kayak Club

SDMAY12-233United States Geological SurveySDMAY12-23

Expensive$5,000/yr to maintainComplex DesignStilling basinTwo story structureUnder ground pipesElectronic recorderTypical USGS Gauge DesignPhoto Credit: USGS http://ga.water.usgs.gov/edu/streamflow1.html Functional SpecificationsTotal Price of Materials < $500Measurement Accuracy: 1inchOperating Temp: -5C to 70CSurvivable Temp: -40C to 70CDaily data transmissionPower save during winter

SDMAY12-23Weather ConditionsOur design must withstand the following:

High WindsIce

Floods

RainSnowSDMAY12-23

Photo Credits last slideRiver ConditionsAny object placed directly in body of water must withstand the following conditions:

Ice formations

Other Floating debrisSDMAY12-23Photo Credits last slideNon Functional SpecificationsLow maintenance costLong battery lifeMinimum: 1 yrRugged design

SDMAY12-23Sensor OptionsPossible Choices:Ultrasonic range sensorFloat SystemWater Pressure SensorAir Pressure SensorAbsoluteDifferential

SDMAY12-23Sensor OptionsList of Choices:Ultrasonic range sensor Basic Float System Moving parts easily break! Water Pressure Sensor - Too expensive !Air Pressure Sensor Absolute Not as simple as differential optionDifferential

SDMAY12-23Sensor OptionsUltrasonic

Pros:Long range (26ft)Withstands extreme temperaturesAccurate to 1cm

Cons:Complicated installation Difficult sensor placementVulnerable to floating debrisRelatively expensive ~ $100Objects could get lodged under sensor, causing incorrect measurementDifferential Air Pressure

Pros:InexpensiveWithstands extreme temperaturesAccurate to 1 inchCan be installed under water

Cons:Under water tubing is needed to connect sensor to rest of the systemCould lose accuracy due to air leakageShorter range ~9 feetSDMAY12-23

Choosing a SensorBest option: Differential Air Pressure SensorWhy?The sensor costs 1/10th of the ultrasonic sensorCan be placed underwater instead of above itCould be buried under sandSand can be used to protect the sensorLeaves the team with more installation options and configurationsSDMAY12-23Under Water HousingConcept and DesignSDMAY12-23AIRWater level is proportional to air pressure inside cylinder

As water depth over cylinder increases, so does air pressure

Housing and tubing buried under a sand bank for added protection against floating debris

Tube to Pressure SensorConcept DiagramMicrocontrollerCell ModulePressure SensorPower BusCharging CircuitVoltage RegulatorBatteryAirWaterSDMAY12-23Voltage RegulatorVoltage RegulatorSolar CellConcept DiagramSDMAY12-23

MicrocontrollerThe team will use the ATMega128 WhyPast experience Can talk directly to cell modem through UARTState machine style in our programming will greatly help out in our debugging phaseSDMAY12-23

Cell ModulePros:Easy to useCommands given through UART

Cons:Poor signal strengthWe will choose a testing location based off of thisPrepaid BillingThe more we test, the more we paySDMAY12-23

HardwareCell Module will text the ISU Canoe and Kayak Club with measurementsMeasurements will occur once per day

Microcontroller will:Take pressure sensor readingConvert pressure reading into water depthSend data to cell module for transmission through UART

SDMAY12-23Power CircuitDetermines the success of our projectMust be designed to keep system powered for an entire yearAll components should contain as low leakage current as possibleForeseen issues we are currently dealing withSnow build up on solar cellBattery failure due to cold weatherStrict power budget

SDMAY12-23Power Circuit HardwarePower Circuit will consist of5 Watt solar cell2 6V Lead Acid BatteriesCharging circuit3 Voltage regulators will be used to keep Microcontroller and Cell Modules input voltage constantSDMAY12-23Power BudgetSDMAY12-23System Power On Consumption:

Telit GM862-GPS Wireless Modem:Voltage: 3.8 VCurrent: 200 Ma

Atmel ATMega128 Microcontroller:Voltage: 2.7 5.5 VCurrent: 20 mA

Freescale MPX2050 Pressure Sensor:Voltage: 16 VCurrent: 6 mANational LM284X Voltage Regulator:Power on: Vshutdown = 2.3 VQuiescent Current = 1.85 mALeakage Current = .5 uA

System Standby Power Consumption:National LM284X Voltage Regulators:Quiescent current = 40 uALeakage Current = .5 uAATMega128 Microcontroller:10 15 uA

Past AccomplishmentsExtensive research on:Possible Environmental ConditionsDifferent options for measuring water heightPower RequirementsWe have purchased the following:MicrocontrollerPressure SensorCell ModuleUnder-water tubingAT&T SIM CardSolar Cells and BatterySDMAY12-23Current TasksTest individual components such as:Cell ModuleMicrocontrollerWaiting for Evaluation boardPressure SensorDesigning power systemChoosing components based off of 5Watt power budgetSDMAY12-23Future TasksTest Power System ComponentsConstruct Under Water Housing componentProgram microcontroller and cell modulePut system togetherCreate working prototype by spring thawUpon Spring Thaw:We will field test our prototype in a local stream

SDMAY12-23Testing RequirementsOur team will test the following:Accuracy of water height measurementAir leakage in under water housing unit and tubePower ManagementCan solar cell keep system charged up for a year?Wireless signalsMax and Min operating temperaturesOverall ruggedness of systemWill the system hold up to extreme weather conditions such as rain, snow, hail, wind?SDMAY12-23Project StatusMicrocontroller and Cell Module have arrivedPower Components have been orderedUnder water housing has been designed and will be built in the coming weeksSoftware implementation has been researched and test code is currently under development

SDMAY12-23Main GoalThe team is working hard to complete a working prototype by spring thawThis goal has been set by our advisor who has stressed this goal since day oneField testing our system is vital and will be used to point out any weaknesses our system might have that controlled testing could not.SDMAY12-23Questions ?Brief SummaryStream depth gaugeComponentsPressure sensorMicrocontrollerCell ModulePower Circuitry Major TasksImplement codeBuild prototype by spring thaw??????SDMAY12-23Image SourcesHigh Winds http://freeimagefinder.com/pic/scargill.htmlRain" http://www.desicomments.com/desi/rain/Floods http://www.securityworldnews.com/2011/09/28/dont-become-the-victim-of-a-flood/mailbox-in-flood-waters/Snow http://wallpaper-s.org/42__Snow-Covered_Trees,_Varmland,_Sweden.htmIce http://www.danzfamily.com/archives/2007/12/tulsa_ice_storm_pictures_update.phpIce Formations http://www.minnesotansforglobalwarming.com/m4gw/2009/03/ice-blasted-to-put-end-to-bismarck-flood.html Other Floating Debris http://www.paddlinginstructor.com/blog/general-news.html?start=20All other images were taken from Microsoft Office Clip Art

SDMAY12-23