SDMAY12-23

Stream Depth GaugeTeam: SDMAY 12-23Team MembersJohn HendersonCurt LaBargeGreg PearsonYixin QiaoClient/AdvisorSteve Holland(ISU Canoe and Kayak Club)1Problem StatementIowa flow levels change oftenCurrent 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

SDMAY12-232SolutionDesign and build a low-cost stream depth gauge

The gauge should be:AffordableSelf containedRobust in the environmentCapable of operating for long period of timeCapable of transmitting measurements wirelessly

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Market SurveySDMAY12-23

Current gauging done mostly by United States Geological Survey

These gauges are expensive$5,000/yr to maintain

Complex 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

SDMAY12-23Non Functional SpecificationsLow maintenance cost

Long battery lifeMinimum: 1 yr

Rugged design

Weatherproof

Low power consumption

SDMAY12-23ScheduleSemester 1Conducted researchIdentified design requirementsRough schematic designPurchased major components

Semester 2Purchased new parts as neededProgrammed micro-controllerImplemented cell moduleComprehensive testing of equipmentPCB designSDMAY12-23

Concept SketchSDMAY12-23

Under 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 SensorSystem DesignAtmel ATMega128Telit GM-862Freescale MPX2050SDMAY12-23

Power DesignVoltage Regulators5 W Solar PanelCharging CircuitTwo 6 Volt Batteries

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Software DesignState Machine

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Block DiagramSDMAY12-23

Hardware ChangesLevel ShiftersMC14504BDR2GOSCT-NDVoltage RegulatorsLT1764AEQ#PBF (Cell Modem)TPS7A1650DGNR (Microcontroller)Instrumentation Amplifier

SDMAY12-23Software ChangesWatchdog timerDebuggingUART USBLEDsBuzzerAT CommandsConsolidated StatesSDMAY12-23

LED Helper4 LEDs on the CEREBOT II boardTo display the values by binary numberIndicates the number of digits of the variableDisplay from the least significant digit to most significant digitHelped in testing temperature sensor and pressure sensorSDMAY12-23

Sleep TestingUsed for power saving6 sleep modesIdle, ADC Noise Reduction, Power-down, Power-save, Standby, Extended StandbyAtmega128 doesnt support Watchdog interruptIdle mode with Timer0

SDMAY12-23Temperature Sensor TestingFind the output of 32F Cutting pointWhen lower than 32F, go to sleepWhen higher than 32F, measure the pressureTemperature chamber was used to find cut-off point.SDMAY12-23

Pressure Sensor TestingSDMAY12-23Instrumental amplifier to obtain the difference of the two outputsWith gain of 4000 (for testing)Max output of the amplifier is 5VMeasures from 2 to 15 inchesAccurate to 1 inchTested with a 2-liter bottle with 9-inch hight

Testing the Cell ModemCell Modem Tests happened in two phasesTesting AT commands with a computer via USB.Testing UART communication between microcontroller and Cell Modem

AT CommunicationCell Modem is controlled via different AT CommandsFirst Testing stage tested the usage of these AT commands:ATAT+CREG=?AT+CMGF=1AT+CMGS=AT#SHDN

UART CommunicationSecond Phase of Testing involved UART Communication between the Cell Modem 3V logicMicrocontroller 5V logicVoltage level shifter

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UART CommunicationWe used USB to Serial device that could read UART communication to test.Showed us transmitting signal to make sure signal was correct

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Full Software TestingFor the full Software Testing, we breadboarded all components together.System could run through each state in the State machine.Each component worked together with everything assembled

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ConclusionsOur device performs its intended purpose: To measures and transmit an accurate water heightThe device could be easily expanded upon: Database to store river height informationSDMAY12-23

Lessons LearnedWe learned that communication is key to getting things done properly.The project gave us a more realistic view of what problem solving is likeHaving the right tools make getting the job done exponentially faster SDMAY12-23Questions ?Brief SummaryStream depth gaugeComponentsPressure sensorMicrocontrollerCell ModulePower Circuitry ??????SDMAY12-23