Spring Plan
the gEEk squad
Elizabeth Reed
Michael Cozzolino
Colleen O’Hagan
Andrew Williams
Gantt Chart
2
Solution – System Organization
Swimmer’s
Eye
Sensing
1. Receive
Data:
Passive IR
2. Transmit
Data to
Processor
Signaling
Processing
Notification
1. Receive
Data from
Sensor
1. Receive
Signal from
Processor
2. Send
Signal to
Notification
Device
2. Activate
Vibration:
on stimulus
3
Sensing Technology
Factor
Wt
Sensor:
RFID
IR
US
T-B
Cost
5
-1
1
-1
-1
Underwater
use
5
-1
1
1
1
Accuracy
3
0
0
0
0
Range
5
0
0
1
1
Size
3
1
1
1
1
Ease of
Use
3
1
1
0
1
Tunable
1
1
1
1
-1
-3
17
9
10
Total:
4
Sensing Timeline:
• Develop and Build a Test Circuit
– Deadline: January 24
• Test and Characterize Sensor
• Person Out of Water
• Person In Water
– Deadline: February 5
• Calibrate Sensor for Pool
– Deadline: February 28
5
Infrared Sensors
• http://www.kube.ch
c172
6192
• http://www.electronics123.com
RE200B
6
Develop Sensor Circuit
• Want
Resistor
output
and Capacitor
of the sensor
values
to trigger
device onlycircuit
determine
when behavior
the swimmer is
• there
Output of the sensor circuit will go
– Immunity
to noise using a low pass
to
the microcontroller
filter and comparator
Vdd
R2
Out
To processor
R1
C
7
Test and Characterize Sensor
•Evaluate different sensors based on
criteria in Pugh chart
Factor
Weight
Part
Operation in water
5
Small
3
Range
5
Accuracy
5
Precision
5
Tunable
1
Cost
1
Ease of Implementation
3
c172
6192
RE200B
Total:
8
Characterize Sensors
• Test sensors with person outside of
water to learn how they work
• See how changing voltage and/or
pitch can change range of
operation
9
Calibrate Sensor for Pool
• Find out how being around water
affects the sensor output and
compensate:
– Determine exact location and
orientation necessary
– Determine best method of tuning the
device
– Use shielding to prevent sensor from
sensing swimmers in adjacent lanes
10
Analyze Output Signal
• Approaching versus departing
• Multiple actuations for each turn?
• Gradient in output over distance
• Other considerations
11
Signaling
Notification
Signal
Vibrating
Motor
Notification
Transmitter
Signal
IR Sensor
Swimmer
Presence
Reader
Receiver
Swimmer
Presence
Detection
Presence
Status
Processor
12
Signaling Timeline:
• Choose Vibrating Motor
– Deadline: January 23
• Pick Communication Scheme
– Deadline: January 17
• Identify Voltage Change
– Deadline: February 9/12
• Transmit to Receiver
– Deadline: February 9
• Receiver to Buzzer
– Deadline: February 16
• Integrate
– Deadline: February 28
13
Vibrating Motors
Offset Weighted Shaft
DC Coin Motor
14
Vibrating Motors
• Offset Weighted Shaft
– All Electronics Corp. (CA)
– 1.5 ~ 3.0 Vdc @ 62 mA
– 0.24” dia x 0.5” long
• DC Coin Motor
– Chongqing Linglong Electronic Co.
(China)
– 2.5 ~ 4.0 Vdc @ 85 mA
– 12 mm dia x 3.4 mm thick
15
Vibrating Motors
Factor
Small
Vibration
Strength
Weight
Type
Offset
Weighted
Shaft
DC Coin
Motor
5
3
Power
needed
3
Gradient
1
Total:
16
Pick Communication Scheme
• Possible Devices:
– RF Transmitter and Receiver
– Ultrasonic Transmitter and Receiver
http://www.laipac.com
Factor
Weight
Small Receiver
5
Behavior near water
5
Cost
3
Type
Ultrasonic
RF
http://www.napier.co.uk
Total:
http://www.jameco.com
17
Identify Voltage Change
• Plan
– Rising vs. falling edge
– Coming vs. going
• Test
18
Transmit to Receiver
• External Stimulus
• Switch Transistor
19
Receiver to Buzzer
• Test Circuit
Integrate
• Microcontroller through to buzzer
20
Post – Subsystems Timeline
• Refined Encasing on Swimmer
 March 1 - March 16
• Integrate Subsystems
 March 1 - April 2
• Build and User Interface
 April 3 - April 10
• Final Testing
 April 11 - April 25
• Filming and Documentation
 April 26 - May 2
21