Project Orion
TekBand
Cam Proctor
Ramsey Khudairi
Tom Gilbert
Chad Young
Electrical and Computer Engineering
1
Outline
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Motivation
Design
Band & Mold
Microcontroller
Bluetooth
Battery
Memory
Q&A
Electrical and Computer Engineering
2
Motivation – Cellular Phone Interface
 Call, Text, & Emergency Notification
• Uses:
• During Meetings
• In Class
• On the Road
• Will lead to:
• Safer Driving
• Less Interruptions
Electrical and Computer Engineering
3
Motivation – Wireless Storage
 Wireless Data Storage
• Uses:
• On the run
• During group projects
• Will lead to:
• Protection from Identity Theft
• Fewer lost files
• Greater Convenience
Electrical and Computer Engineering
4
Design
 Goals:
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Interface with Cell Phone to alert user of calls and
messages
Interface with PC to program the band
Interface with PC as wireless storage device
Maintain Fashion & Style
 Our wristband will contain:
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Microcontroller
Bluetooth module
MicroSD card
Lithium ion battery
Electrical and Computer Engineering
5
The Band-Materials
Durability
Elasticity
Degradation
Cost
Urethane Rubber
high
low
none
second least
expensive
Latex Rubber
low
high
rots from long
exposure to
sweat
least expensive
Silicone Rubber
high
high
none
most expensive
Electrical and Computer Engineering
6
The Band-Construction
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Target Size: 200mm x 5mm x 22mm
Two-Part Silicone Rubber
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1:1 Ratio
Pour in mold
Cure time of a few hours
Can be bought at any local craft store
~$20/lb.
Electrical and Computer Engineering
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The Mold
Silicone
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Rubber-To-Rubber mold release
Master mold
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Mold poured around wooden band
Other options
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Putty
www.amazingmoldputty.com
Electrical and Computer Engineering
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The Clasp
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Neodymium
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Rod Magnets
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~$10-$20
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Trials
Electrical and Computer Engineering
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Microcontroller Considerations
 Form factor
• Must be small enough to fit inside band
 Low power
• Running continuously
 Interface with peripherals
• I/O for user control
• Interface with Bluetooth
module
• Read/Write to storage
media
Electrical and Computer Engineering
10
Microcontroller Capabilities
 I/O
• 3 pins to drive single tri-color LED
• Possible analog inputs for gyro, microphone, etc.
 SPI (Serial Peripheral Interface)
• Read/Write MicroSD card
• Communicate with Bluetooth module (KC-21)
 UART (Universal asynchronous receiver/transmitter)
• Data transfer from Bluetooth module (KC-21, BTM-182)
Electrical and Computer Engineering
11
Microcontroller Solutions
PIC16F1827
(Microchip)
PIC16F1824
(Microchip)
PIC16F1938
(Microchip)
C8051F531AIM (Silicon
Laboratories)
ATTINY2313
-20MU-ND
(Atmel)
SPI
2
1
1
1
1
USART
1
1
1
1
1
I/O Pins
16 (18 pin)
12 (14 pin)
25 (28 pin)
16 (20 pin)
18 (20 pin)
ADC
10 bit
10 bit
10 bit
12 bit
n/a
Program
Memory
7kB, flash
7kB, flash
28kB, flash
8kB, flash
2kB, flash
Size
4x4mm
3x3mm
4x4mm
4x4mm
4x4mm
Power
30nA standby,
100μA @1MHz
20nA standby
typical, 600nA
operational
60nA
Standby,
150μA @1MHz
.1mA
operational
<.1μA
standby,
230μA @
1MHz
Cost
$1.75
$1.40
$2.25
$2.55
$2.65
Electrical and Computer Engineering
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Best Candidates
 PIC16F1827 (Microchip)
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Good middle ground
2 SPI ports
Low power
Small size, multiple chips…
 PIC16F1938 (Microchip)
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Large program memory
Small form factor
Higher cost
Greater power consumption, critical
Electrical and Computer Engineering
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Selecting a Microcontroller
 PIC16F1827 (Microchip)
• Appears to be the ideal candidate
• Low power and cost
• Small size, possibility for >1 chip in bracelet
• 2 SPI ports and USART
• Start with this chip, others as fallback
• Middle of the road – good starting point
Electrical and Computer Engineering
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Selecting a Bluetooth
Electrical and Computer Engineering
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Bluetooth modules
Module
Dimensions
Power
Transmit Rate
Range
Cost
LMX9830*
9x6x.86mm
65mA
0.704Mbps
10m
17.15
WRL-09913
1.4x2.5cm
58mA
0.704Mbps
10m
18.95
KC-21
27x15x2.5mm
90mA
3Mbps
20m
36.00
CSR1000**
5x5x0.6mm
60mA
24Mbps
50m
NA
* Does not come with an antenna
** Not yet available on the market
Electrical and Computer Engineering
16
Battery Considerations
 Form factor
• Small enough to fit inside band (< 20mm wide x 2mm thick)
 Capacity: 100mAh
• Approx. 100mA during read/write to MicroSD
• Approx. 90mA during Bluetooth transmit
 Must be rechargeable
• Wireless Charging
 Strategy: Multiple Small Batteries
Electrical and Computer Engineering
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Battery Options
 Coin Cell:
Module
Voltage
Capacity
Dimensions
Cost
ML-2020/F1AN
3.0V
45mAh
20mm diam x 2mm thick
$2.68
ML 1220/F1AN
3.0V
17mAh
12.5mm diam x 2mm thick
$2.38
MS920SE-FL27E
3.1V
11mAh
9.5mm diam x 2mm thick
$2.05
MS621FE
3.0V
5mAh
6.8mm diam x 1.5mm thick
$0.94
 Thin Film Surface Mount:
Module
CBC050-M8C-TR1
Voltage
Capacity
Dimensions
3.8V
50uAh
8mm x 8mm ultrathin
Electrical and Computer Engineering
Cost
$3.82
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Battery Form Factor Considerations
ML621
6.8mm
5mAh
ML2020
20mm
45mAh
MS920SE
9.5mm
11mAh
50mm
(1/4 of
total
band
length)
MS920SE
12mm
17mAh
CBC050
8mm
50uAh
Electrical and Computer Engineering
20mm
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4GB Memory – Possible Add-on
 MicroSD
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Small – 11mm X 15mm X 1mm
Voltage Range: 2.7 – 3.6V
Clock Rate: 0 – 25MHz
Supports Serial Peripheral Interface (SPI)
Assuming 25MHz clock, Read/Write time: 40s/Gb
Power:
• Sleep – 150uA max
• Read – 100mA max
• Write – 100mA max
• Cost: $3 - $5
• Performance: -25oC to 85oC
Electrical and Computer Engineering
20
MicroSD Communication
 Serial Peripheral Interface (SPI) protocol
• Data clocked with clock signal (SCK)
• Clock signal controls when data is changed and read
• SPI is Sychronous
• Data rate will change to accommodate changing clock rate
• SSP or MSSP module in PICmicro device allows SPI
Electrical and Computer Engineering
Pin #
Name
Type
Description
1
RSV
2
CS
Input
Chip Select
3
DI
Input
Data In
4
Vdd
Supply
Supply Voltage
5
SCLK
Input
Clock
6
Vss
Supply
Supply Ground
7
DO
Output
Data Out
8
RSV
Disconnected
Disconnected
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Timeline
Oct 17-23
Oct 24 - 30
Oct 31 - 6 Nov 7 - 13 Nov 14 - 20
Nov 21 - 27
Nov 28 - 4
Battery - Tom
Purchase
Test & Reconsider Components
Integrate
Microcontroller - Cam
Purchase
Test & Reconsider Components
Integrate
Bluetooth - Chad
Purchase
Test & Reconsider Components
Integrate
Band Construction - Ramsey
Purchase Supplies
M
D
R
Build Protype Band
Test & Evaluate
Construct Prototype Mold
Memory - Tom & Ramsey
Purchase Card
Test Power Consumption
Integrage or Eval Other Options
Electrical and Computer Engineering
22
Budget
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Band Construction
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Bluetooth
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Module: $40
Development Kit: $100-$150 (depending on module)
Total: $140-$190
Microcontroller
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Supplies for 10 Bands & Mold: $60
Rubber to rubber mold release: $10
100 Magnets: $20
Total: $90
Module: $1.20
Breakout Board & Dev Kit: $165
MicroSD
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Module: $3-$5
Electrical and Computer Engineering
23
Conclusion
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Our wristband will contain:
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Microcontroller
Bluetooth module
microSD card
The final product will:
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Interface with Cell Phone to alert user of calls and messages
Interface with PC to program alert preferences
Possible Addition: Interface with PC as wireless storage device
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Key constraints: Power and Size
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Deliverables by MDR:
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Prototype of electronics working on board
Prototype wristband w/o HW
Electrical and Computer Engineering
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