Team 5: Good Vibrations
18549: Embedded Systems Design
Bryce Aisaka
Justin Beaver
Tony Felice
Skanda Mohan
Team Members
Bryce Aisaka
Justin Beaver
Tony Felice
Skanda Mohan
baisaka@andrew.cmu.edu justinbeaver8@gmail.com romman0012003@gmail.com skandam@andrew.cmu.edu
http://www.ece.cmu.edu/~ece549/spring10/team5/index.html
Concept
• A silent, portable, comfortable, batteryoperated, phone activated, vibrating pillow
cover
• User sets time to wake up via phone UI,
pillow vibrates at that time to wake user
• Competitive Advantages:
– Portability: Just need to carry your cell phone
and our pillow cover
– Customizable: Can use our pillow cover with
the pillow of your choice
Goals
• Silent: Should not wake up anyone else
• Portable
• Battery Operated: Does not need to be plugged
in during usage
• Phone activated: Can use the cell phone that
you already own to activate the pillow vibration
• Customizable
• Fail-Safe: Sound is emitted only if person does
not wake up after set time limit
• Effective: Needs to be able to wake someone up
Architecture
Serial port Bluetooth module
Arduino Nano
Bluetooth enabled
Android phone
Solarbotics VPM2
Vibrating Disk Motor
3x Triple A’s
Components
Solarbotics
VPM2
Vibrating Disk
Motor
Padding
+Covers
Arduino Nano
+Bluetooth module
(BlueSmirf Gold)
Battery
Holder
+AAAs
Bluetooth Enabled
Smart-Phone
(Motorola Droid)
User Interface
Experimentation Campaign
• Bluetooth Range
– Method: Stand at a certain distance and measure the time it
takes for the BT connection to be established and a byte to travel
round trip
– Took 30 measurements at increments of 5 feet to ensure
reproducible results
• Idle Power Consumption
– Method: Leave all components of the system running in idle
state, measure how long it takes for batteries to run out
• Continuous Power Consumption
– Method: Leave the vibration motors continuously running,
measure how long it takes for batteries to run out.
Experimentation Campaign (cont.’d)
• User Survey
– Method: Ask 10 test users to use our product
and answer a series of questions
– Questions address comfort of pillow,
willingness to adopt our product, and pricing
of a mass-produced version of our product
Experimental Results
• Bluetooth range test results
• Idle Power Consumption: ~24 hours
• Continuous Power Consumption: >65
minutes
Experimental Results (cont.’d)
• Number of users who said…
–
–
–
–
–
–
The pillow was comfortable while handling it: 9/10
The pillow was comfortable while lying on it: 10/10
They would wake up from the high vibration setting: 9/10
They would wake up from the medium vibration setting: 8/10
They would wake up from the low vibration setting: 2/10
They would prefer our product to how they currently wake up: 6/10
• Of the people who said they prefer our product, the number
of users who said…
– They would be willing to charge the pillow as often as they charge
their cell phone: 4/6
– They would be willing to pay up to $20 for our product: 6/6
– They would be willing to pay up to $30 for our product: 2/6
– They would be willing to pay more than $30 for our product: 1/6
Insights from Measurements
• Battery life is sufficient, but daily
recharging may be required
• Bluetooth range is long enough for typical
bedroom use
• Our comfort and effectiveness
requirements seem to have been met
• Users seem reluctant to break habits and
switch to a newer, novel way to wake up
• The target price is $20
Open Issues
• Longer battery life
• A 5V power solution for more powerful
vibration
• Sensors on pillow cover
• Making the pillow cover washable
Conclusions
• Some things we learned:
– Arduino has much more computing power than we
actually need, but is really convenient
– Bluetooth is surprisingly easy to use, once you find
the proper UUID
• What we accomplished:
– Building a finished product
• What we would do differently:
– Order parts earlier