SDSU -Senior Design Project Spring ‘08
Ronald Ramos
Project Manager Heather Schnaath Manuel Lechuga
Report Editor Parts Manager
Huy Le
Presentation Eric Woodward
Coordinator Web Designer
SDSU -Senior Design Project Spring ‘08
Ronald Ramos
Project Manager Heather Schnaath Manuel Lechuga
Report Editor Parts Manager
Huy Le
Presentation Eric Woodward
Coordinator Web Designer
SDSU -Senior Design Project Spring ‘08
Ronald Ramos
Project Manager Heather Schnaath Manuel Lechuga
Report Editor Parts Manager
Huy Le
Presentation Eric Woodward
Coordinator Web Designer
SDSU -Senior Design Project Spring ‘08
Ronald Ramos
Project Manager Heather Schnaath Manuel Lechuga
Report Editor Parts Manager
Huy Le
Presentation Eric Woodward
Coordinator Web Designer
“The right choice”
“The right choice”
Background
SDSU’s Assistive Device Assessment Program (ADAP) is
currently looking for new ways to evaluate cognitive
functions of persons with severe communicative
limitations
Children and/or adults have difficulty identifying and
making a decision between two objects
Devices are limited and don’t offer a variety of ways to
evaluate a person
Charlotte from ADAP Lab
iLearn Assistive Device
Specific Performance Criteria
Have both clearly distinguishable visual and
auditory indicators for up to four choices
Able to digitally record 4 messages for up to 5
seconds each
Have an adjustable automatic scanning speed
Have a manual scanning option
Able to have either two or four LEDs active
Have an adjustable volume control
Rechargeable battery operation with battery life of
at least 3 hours
Interface
Interface Specs
Weight: ~2.5 lbs
Size: 8” x 16”x 6.5”
# of targets: 4
# of inputs: 5
◦ 4 front
◦ 1 universal
Programmable: Yes Start
Manageability: Sturdy, Speaker
Manual
water resistant control
input
Left Side Right Side
Toggle for
tones, Scanning Speed
standard,
manual
scanning
Volume
Toggle for LEDs On/Off
Back
Instructions
Battery Compartment
Charging
Indicator
Barrel Jack for
Wall Cube
Inside
Recharging PCB Voice PCB MCU PCB
Design Approach
4 main groups of focus:
Main Board
Secondary
Boards
Interface
controls
Power
Microcontroller
Microcontroller Specs
40 pins to control all
toggles, LEDs, speed
and volume of the
iLearn device
Rapid change on
interrupt capability
Headers for easy
interfacing
Voice Circuit
Voice Specs
Standalone mode for
easy interfacing
Push buttons that
include:
◦ Play
◦ Forward
◦ Erase
◦ Record
◦ Volume
Operates 2.4 – 5.5V
Sampling frequency @
80 Khz for 90 seconds of
record time
Recharging Circuit
Recharging Circuit Specs
# of cells: 6 AA NiMH
Charge rate: 1A
Safe automatic timeout
period: 180 min.
Indicators: LED for wall
cube input
# of 5V outputs: 2
◦ 1 for Microcontroller
◦ 1 for voice
Project Scheduling & Budgeting
Gannt Chart
Organized schedule into certain phases
◦ Design, Research, Development and Experiments, MCU
Programming, Fabrication, Testing
Bottom half of chart set milestones and important due dates
Bulk of time dedicated to programming and system
integration
Budget
COST SUMMARY
ITEM
PART DESCRIPTION QTY TOTAL
REF
1 ISD1790PY-ND (Voice chip) 1 $9.16
2 Maxim 712 (Charging Chip) 1 $0.00
3 16F887 Microcontroller 1 $0.00
4 Microphone Cartridge 6mm Omni 1 $1.86
5 Speaker 8 ohm 2W 84 dB 40x28 mm 2 $7.77
6 Assorted Switches 27 $11.40
7 Assorted capacitors, resistors, diodes and transistors 30 $0.00
8 Housing 1 $0.00
9 Rechargeable Battery and battery holder 10 $21.69
10 Assorted LEDs 9 $0.00
11 Assorted Connectors 5 $7.77
12 Miscellaneous N/A $47.00
Final Cost: $106.65
Impact of device
Current devices on the market only allow
scanning of LEDs
By providing 3 other test options, the
device can be used to make a wide range
of evaluations
Visual aids and LEDs help stimulate the
brain and engage patients
Video demonstration
Thank You
Please visit us at:
Http://ilearn.sdsu.edu
and
Come see us at Design Day
May 9, 2008 @ 12:00pm