Electronic Diver Safety Electronic Diver Safety Log - eDSLLog - eDSL

By:By:Mirayma V. RodrMirayma V. Rodrííguezguez

Roberto RiveraRoberto RiveraCarlos RubertCarlos Rubert

Microprocessor Interfacing (ICOM 5217)Microprocessor Interfacing (ICOM 5217)May 5, 2006 May 5, 2006

OutlineOutline

• IntroductionIntroduction• Theoretical BackgroundTheoretical Background• Software DesignSoftware Design• Hardware DesignHardware Design• Achievements and LimitationsAchievements and Limitations• ConclusionsConclusions• Future WorkFuture Work• Q&A sessionQ&A session

IntroductionIntroduction

• What is eDSL?What is eDSL?– The Electronic Diver Safety Log is a device for The Electronic Diver Safety Log is a device for

planning and monitoring safety dives.planning and monitoring safety dives.– Use pressure lectures to calculate depth.Use pressure lectures to calculate depth.– Use traditional method of dive tablesUse traditional method of dive tables

IntroductionIntroduction

• Our MotivationOur Motivation– Provide a device to increase safety in recreational Provide a device to increase safety in recreational

divedive– Help divers to plan different dives in a safe way using Help divers to plan different dives in a safe way using

dive tables.dive tables.

• Project DescriptionProject Description– Use of a pressure sensor to calculate depthUse of a pressure sensor to calculate depth– Use dive tables to get time and depth limitsUse dive tables to get time and depth limits– Alert divers when time or depth limits are reachedAlert divers when time or depth limits are reached

Theoretical BackgroundTheoretical Background

• Underwater explorationUnderwater exploration– SCUBA DivingSCUBA Diving

• Self-Contained Underwater Breathing ApparatusSelf-Contained Underwater Breathing Apparatus

– Safe and secure diving experienceSafe and secure diving experience• Decompression SicknessDecompression Sickness

– Air MixturesAir Mixtures» Nitrogen and AirNitrogen and Air

– PressurePressure– Nitrogen in BodyNitrogen in Body

Dive TablesDive Tables

• Used for planning a safe and secure dive.Used for planning a safe and secure dive.• Developed by the US Navy and NOAADeveloped by the US Navy and NOAA• Depends on the air mixtureDepends on the air mixture• Dive TablesDive Tables

– Table OneTable One• Used to calculate the Nitrogen Level after spending time at a Used to calculate the Nitrogen Level after spending time at a

particular depth.particular depth.– Table TwoTable Two

• Used to calculate the Nitrogen Level after spending time on Used to calculate the Nitrogen Level after spending time on the surface prior to your second dive.the surface prior to your second dive.

– Table ThreeTable Three• Used to calculate the Residual Nitrogen Time after Used to calculate the Residual Nitrogen Time after

completing the surface interval.completing the surface interval.

Table # 1Table # 1• Used to calculate the Used to calculate the Nitrogen Level Nitrogen Level after spending after spending

time at a particular depthtime at a particular depth

Table # 2Table # 2• Used to calculate the Nitrogen Level after spending time Used to calculate the Nitrogen Level after spending time

on the surface prior to your second dive.on the surface prior to your second dive.

Table # 3Table # 3• Used to calculate the Residual Nitrogen Time after Used to calculate the Residual Nitrogen Time after

completing the surface interval.completing the surface interval.

Software DesignSoftware Design

• User InterfaceUser Interface– Enter information about divesEnter information about dives

• Water TypeWater Type– FreshFresh– SaltSalt

• Number of DivesNumber of Dives• Information about divesInformation about dives

– Starting Nitrogen LevelStarting Nitrogen Level– Desire Depth and MinutesDesire Depth and Minutes

Software DesignSoftware Design

• Software BasicsSoftware Basics– Use dive tables to acquire time and depth limitationsUse dive tables to acquire time and depth limitations– The pressure is use to calculate the depth using the formula:The pressure is use to calculate the depth using the formula:

• This formula is derive from:This formula is derive from:

– When time or depth limits is reach, the system will alert the When time or depth limits is reach, the system will alert the diver by vibratingdiver by vibrating

– InterruptsInterrupts• Seconds (Time)Seconds (Time)• ADC (Pressure Sensor)ADC (Pressure Sensor)• UARTUART

81.9*

)1000*2(*)1(*28.3)(density

PftDepth

)12(*81.9*12 DDdensityPP

Software DesignSoftware Design

• Software ConsiderationsSoftware Considerations– Arrays in code vs. Memory SpaceArrays in code vs. Memory Space

• Tables SizeTables Size– Depth RestrictionsDepth Restrictions– Time RestrictionsTime Restrictions

System Block DiagramSystem Block Diagram

Hardware ConsiderationHardware Consideration

• Low PowerLow Power

• Low CostLow Cost

• PortabilityPortability

• Different Power SourcesDifferent Power Sources

Hardware ConsiderationsHardware Considerations

Major Considerations for Underwater Major Considerations for Underwater OperationOperation

- Temperature- Temperature

- Pressure- Pressure

Safety ConsiderationSafety Consideration

- T- The implementation of a Battery Gas Gaugehe implementation of a Battery Gas Gauge

Achievements & LimitationsAchievements & Limitations

• Display of variations in current depth and Display of variations in current depth and time.time.

• Alert System triggered by time and depth Alert System triggered by time and depth limits.limits.

• Max depth: 99 feet (400kPa or 130 ft from Max depth: 99 feet (400kPa or 130 ft from sensor)sensor)

• Prototype size may be too big.Prototype size may be too big.

• Unsuccessful log data retrieval.Unsuccessful log data retrieval.

• Limited to three dives.Limited to three dives.

ConclusionsConclusions

• Full integration between system hardware Full integration between system hardware components and software.components and software.

• Functional sensor reading for depth.Functional sensor reading for depth.

• Increase in diving safety due to alert Increase in diving safety due to alert system.system.

Future WorkFuture Work

• Size & Power Consumption reduction.Size & Power Consumption reduction.

• Log RetrievalLog Retrieval

• External programming.External programming.

• Longer depth rangeLonger depth range

• Other types of sensing signals.Other types of sensing signals.

• Other type of displayOther type of display

QuestionsQuestions