Download Temperature – Circuit

Wearable Wireless
Physiological Sensors
Daniel Bishop
Josh Handley
Phillip Hay
Christina Hernandez
Rosy Logioia
Gouri Shintri
Clay Smith
Adam Stevenson
Goals and Objectives
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Measure blood volume pulse
Measure skin resistance
Measure temperature
Record measurements on wearable device unit
Transmit measurements wirelessly to a
computer
• Display measurements on Graphical User
Interface in real time
Recent Issues
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BVP Sensor – Correctly amplifying and filtering
signals
GSR – Reverse engineering safely
Convert bulky circuit into small and wearable
device
Understanding Eagle
Size and availability of parts
Compatible design to Dr.Liu’s requirements
Getting Chipcon to process information
Debugging hardware
Sensors Team - Goals
Objectives – Done
Objectives – To Do
• Reverse engineer BVP sensor
•Properly filter BVP signal with 2nd
order low pass filter
• Reverse engineer temperature
sensor
• Calibrate and test temperature
sensor
•Reverse engineer GSR sensor
• Condense circuits into wearable
item
• Integrate sensors and board
• Test / Debug integration
• Integrate sensors / board with
software
• Test / Debug complete
configuration
• Present final product
Temperature – Circuit
Temperature – Calibration
Voltage to Temp Conversion
y = 47.985x + 76.513
R2 = 0.9229
140
Temperature (F)
120
100
80
60
40
20
0
0
0.2
0.4
0.6
V2-V1 (V)
0.8
1
Temperature – Testing
Thermometer
Positions
Temperature
◦F
Measured
Voltage V
Calculate
Voltage V
% Error
Gouri’s palm
91.6
.314
.314
0
Zach’s palm
97.2
.442
.431
2.55
Di’s palm
96.4
.403
.414
2.66
Di’s fingers
94.9
95.9
.340
.360
.383
.404
11.22
10.89
Pulse Oximetry – Circuits
 LED Circuit
Photovoltaic
Circuit 
Skin Resistance
•Waiting on extra samples to arrive
•Reverse engineer sample to learn how GSR sensors work
•Build a working prototype on breadboard using knowledge
and information from sample
•Calibrate sensor
•Proposed skin resistance circuit
Board Design Team - Goals
Objectives – Done
Objectives – To Do
• Comprehension of Chipcon 2400
and Microcontroller
• Test schematic
• Board Schematic (Eagle)
• Research Parts – Size and $$
• Send off schematic for board
creation
• Integrate sensors and board
• Test / Debug integration
• Integrate sensors / board with
software
• Test / Debug complete
configuration
• Present final product
Board Design
Microcontroller and Chipcon 2400
• Microcontroller
• 32 I/O Pins
• 8 analog inputs pins (100 ksps)
• Max amplification = 16, variable
• UART (Built-In)
• Chipcon CC2400
• 4 pin SPI bus
• 6 optional digital interfaces
• 3 pin antenna connection
• 2.4 GHz transceiver
Custom Circuit Board
PCB Layout
Software Team - Goals
Objectives – Done
Objectives – To Do
• Comprehension of Chipcon 2400
and Microcontroller
• Transmission software
•Analog input software
•Receiving Software
•USB software
•GUI
• Integrate software with sensors /
board configuration
•Test / Debug complete
configuration
• Present final product
Analog Input
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Code
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Initialize timer
Poll sensors continuously
Convert to digital signals
Testing
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Signal generator
Communication
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Code
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Initialize Chipcon
registers/clock
Construct/Transmit
packets
Testing
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Writing/Reading
chipcon registers
Set up multiple Chipcon
EBs
Questions?