Electronic Diver Safety Log - eDSL By: Mirayma V. Rodríguez Roberto Rivera Carlos Rubert Microprocessor Interfacing (ICOM 5217) May 5, 2006

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

Introduction What is eDSL?What is eDSL? –The Electronic Diver Safety Log is a device for planning and monitoring safety dives. –Use pressure lectures to calculate depth. –Use traditional method of dive tables

Introduction Our MotivationOur Motivation –Provide a device to increase safety in recreational dive –Help divers to plan different dives in a safe way using dive tables. Project DescriptionProject Description –Use of a pressure sensor to calculate depth –Use dive tables to get time and depth limits –Alert divers when time or depth limits are reached

Theoretical Background Underwater explorationUnderwater exploration –SCUBA Diving Self-Contained Underwater Breathing ApparatusSelf-Contained Underwater Breathing Apparatus –Safe and secure diving experience Decompression SicknessDecompression Sickness –Air Mixtures »Nitrogen and Air –Pressure –Nitrogen in Body

Dive 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 One Used to calculate the Nitrogen Level after spending time at a particular depth.Used to calculate the Nitrogen Level after spending time at a particular depth. –Table Two Used to calculate the Nitrogen Level after spending time on the surface prior to your second dive.Used to calculate the Nitrogen Level after spending time on the surface prior to your second dive. –Table Three Used to calculate the Residual Nitrogen Time after completing the surface interval.Used to calculate the Residual Nitrogen Time after completing the surface interval.

Table # 1 Used to calculate the Nitrogen Level after spending time at a particular depthUsed to calculate the Nitrogen Level after spending time at a particular depth

Table # 2 Used to calculate the Nitrogen Level after spending time on the surface prior to your second dive.Used to calculate the Nitrogen Level after spending time on the surface prior to your second dive.

Table # 3 Used to calculate the Residual Nitrogen Time after completing the surface interval.Used to calculate the Residual Nitrogen Time after completing the surface interval.

Software Design User InterfaceUser Interface –Enter information about dives Water TypeWater Type –Fresh –Salt Number of DivesNumber of Dives Information about divesInformation about dives –Starting Nitrogen Level –Desire Depth and Minutes

Software Design Software BasicsSoftware Basics –Use dive tables to acquire time and depth limitations –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 diver by vibrating –Interrupts Seconds (Time)Seconds (Time) ADC (Pressure Sensor)ADC (Pressure Sensor) UARTUART

Software Design Software ConsiderationsSoftware Considerations –Arrays in code vs. Memory Space Tables SizeTables Size –Depth Restrictions –Time Restrictions

System Block Diagram

Hardware Consideration Low PowerLow Power Low CostLow Cost PortabilityPortability Different Power SourcesDifferent Power Sources

Hardware Considerations Major Considerations for Underwater Operation - Temperature - Pressure Safety Consideration - T he implementation of a Battery Gas Gauge

Achievements & Limitations Display of variations in current depth and time.Display of variations in current depth and time. Alert System triggered by time and depth limits.Alert System triggered by time and depth limits. Max depth: 99 feet (400kPa or 130 ft from sensor)Max depth: 99 feet (400kPa or 130 ft from 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.

Conclusions Full integration between system hardware components and software.Full integration between system hardware components and software. Functional sensor reading for depth.Functional sensor reading for depth. Increase in diving safety due to alert system.Increase in diving safety due to alert system.

Future 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

Questions