Electronic Diver Safety Log - eDSL

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

2. Outline • Introduction • Theoretical Background • Software Design • Hardware Design • Achievements and Limitations • Conclusions • Future Work • Q&A session

3. Introduction • 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

4. Introduction • Our Motivation • Provide a device to increase safety in recreational dive • Help divers to plan different dives in a safe way using dive tables. • Project 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

5. Theoretical Background • Underwater exploration • SCUBA Diving • Self-Contained Underwater Breathing Apparatus • Safe and secure diving experience • Decompression Sickness • Air Mixtures • Nitrogen and Air • Pressure • Nitrogen in Body

6. Dive Tables • Used for planning a safe and secure dive. • Developed by the US Navy and NOAA • Depends on the air mixture • Dive Tables • Table One • 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. • Table Three • Used to calculate the Residual Nitrogen Time after completing the surface interval.

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

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

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

10. Software Design • User Interface • Enter information about dives • Water Type • Fresh • Salt • Number of Dives • Information about dives • Starting Nitrogen Level • Desire Depth and Minutes

11. Software Design • Software 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: • When time or depth limits is reach, the system will alert the diver by vibrating • Interrupts • Seconds (Time) • ADC (Pressure Sensor) • UART

12. Software Design • Software Considerations • Arrays in code vs. Memory Space • Tables Size • Depth Restrictions • Time Restrictions

13. System Block Diagram

14. Hardware Consideration • Low Power • Low Cost • Portability • Different Power Sources

15. Hardware Considerations Major Considerations for Underwater Operation - Temperature - Pressure Safety Consideration - The implementation of a Battery Gas Gauge

16. Achievements & Limitations • Display of variations in current depth and time. • Alert System triggered by time and depth limits. • Max depth: 99 feet (400kPa or 130 ft from sensor) • Prototype size may be too big. • Unsuccessful log data retrieval. • Limited to three dives.

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

18. Future Work • Size & Power Consumption reduction. • Log Retrieval • External programming. • Longer depth range • Other types of sensing signals. • Other type of display

19. Questions