sd card data logger senior design i mid-semester presentation sep 30, 2010
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SD Card Data Logger
Senior Design I
Mid-Semester Presentation
Sep 30, 2010
TEAM
Team Advisor:
Dr. Patrick Donohoe
James Felkins (EE)
Team Leader,
Testing, Web Design
Harry Corey (EE)
Testing, Hardware Design, Software Design
Brendan Babiak (EE)
Software & Hardware Design, Prototype Construction
Jaron Martin (CPE)
Lead Software Design, Prototype Construction
OUTLINE
-Description of S-Drive
-The Problem
-The Solution
-Design constraints
-System overview
-Tradeoffs
-Timeline
-Progress
WHAT IS THE S-DRIVE?
The S-Drive is an OEM module that accepts data through a serial connection and saves it to an SD card.
THE PROBLEM
SD cards are a viable storage medium with unique advantages but involve complex overhead.
SOLUTION
The S-Drive will handle the unwanted overhead and make SD cards a more desirable solution.
TECHNICAL CONSTRAINTS
Name Description
Communication The device must have UART and SPI data connections.
VoltageThe device must support an input voltage between 3.3 and 5 V.
Current DrawThe device must draw a maximum current of 250 mA in active mode, 200 uA in sleep mode, and 10 uA in deep-sleep mode.
Storage MediumThe device must interface with a standard size, 32 x 24 x 2.1 mm SD card.
Memory The device must support all SD cards up to 32 GB.
TECH CONSTRAINTS, CON’T
[1]
SD Version
Name Maximum Capacity
SD 1.x SD 1 GB (revised to support 4 GB)
SD 2.0 SDHC 32 GB
SD 3.0 SDXC 2 TB
A standard-sized SD socket allows for increase compatibility across different sizes of SD cards.
32GB was chosen to support all SD cards through the SD 2.0 specification.
PRACTICAL CONSTRAINTS -
ECONOMICThe device must cost less than $60.
Competitor Price
VDRIVE2 $24.50 [4]
Logomatic v2 $59.95 [3]
Avisaro M20511 99.00 € (~$133) [2]
[2]
[4][3]
PRACTICAL CONSTRAINTS - MANUFACTURABILITYThe device must easily fit and integrate into other systems.
•Provided on a PCB
•No larger than 5 in2
•Easily mountable
SYSTEM OVERVIEW
SYSTEM OVERVIEW
SYSTEM OVERVIEW
SYSTEM OVERVIEW
SYSTEM OVERVIEW
SYSTEM OVERVIEW
SYSTEM OVERVIEW
TRADEOFFS – FILE ALLOWANCENumber of Simultaneous Open Files Allowed
Convenience to the User
Percent of remaining RAM available for buffer (%)
How often SD card must be powered on
1 Least convenient 100 Least often
2 More convenient 50 More often
More than 2 Most convenient < 33.3 Most often
TRADEOFFS - MICROS
PIC Available FAT libraries?
Available from Manufacturer?
Available Program Memory (kB)
RAM(KiB) Estimated Sleep Current Draw
PIC24FJ64GA102
Yes Yes 64 8 ~10 uA
PIC24HJ32GP202
Yes Yes 32 2 ~100 uA
TIMELINE
Month August September October November
Research
Hardware design
Programming
Prototyping
Testing
Final Prototype
TASKS ACCOMPLISHED
Hardware Design
Ordered Parts
-Microcontroller
-SD card socket
Prototype construction
-SD card socket installed
-Power supply
Began software development
-Successfully written data to an SD card
PROTOTYPING
PROTOTYPING
FUTURE TASKS
Finish software development
-SD card initialization routines
-FAT16, FAT32 file system management
-input configuration
-buffering scheme
SUMMARY
Problem• SD card overhead is burdensome
Solution• S-Drive will handle overhead
Design Constraints• packaging, current draw, etc.
Technical Tradeoffs• File Allowance (1, 2, or more)• Microcontrollers (PIC24H vs. PIC24F)
REFERENCES[7] Microchip, “PIC24F Family Reference Manual, Sect. 21 UART,” Microchip Technology Inc., January 26, 2010. [Online] . Available: http://ww1.microchip.com/downloads/en/DeviceDoc/en026583.pdf. [Accessed September 14, 2010].
[8] Microchip, “PIC24F Family Reference Manual, Sect. 23 Serial Peripheral Interface (SPI),” Microchip Technology Inc., March 22, 2007. [Online] . Available:http://ww1.microchip.com/downloads/en/DeviceDoc/39699b.pdf. [Accessed September 14, 2010].
[9] STEC, “SLDSxxxBS(I)U Data Sheet,” STEC Inc., March 2008. [Online] . Available: http://www.stec-inc.com/downloads/flash_datasheets/SLSDxxxB_I_U61000-05203.pdf. [Accessed September 14, 2010].
[10] Sparkfun Electronics, “Logomatic v2 Serial SD Datalogger,” On-Line Store,2010.[Online].Available:http://www.sparkfun.com/commerce/product_info.php?products_id=8627. [Accessed:September 14, 2010].
[11] C-ONE Technology Corp., “Wide Temperature Industrial SD Card Product Specification,” May 2010. [Online]. Available: http://www.psism.com/c-1sd.pdf. [Accessed: September 14, 2010].
QUESTIONS?