Stephen Joo and Daniel Kattan
April 16, 2010
ECE 002, Group 8
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We, Stephen Joo and Daniel Kattan are Group
8 of ECE 002. Throughout the semester, we
have learned many things with each lab. We
have faced many challenges and through
them learned a lot. The different projects in
ECE 2 gave us a taste of what’s to come in the
next few semesters of engineering here at
GW.
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Lab introduced different types of sensors
Taught how to test different sensors to
determine optimal range of use as well as how to
write program using those sensors
Sensors tested:
- light sensor
- sonar sensor
- optical rangefinder
- touch sensor
These were critical in next project, creating and
programming an elevator.
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Provided fairly stable results over the entire
spectrum
Useful for wide range of applications
Can reliably detect differences between not only
white and black but also different scales of gray
Can be used to detect subtle changes in lighting,
not just shift from black to white
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Results somewhat unpleasant because only
accurate within certain range
According to results, sensor goes haywire and
gives extreme values or values that are
indiscernible from those around them (i.e.
nonlinear) just outside of small normal range
Makes this sensor ill-suited to all but very crude
applications.
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Results extremely accurate and precise
When we made graph based on data, sensor
provided extremely linear graph.
Sensor is ideal for any application for measuring
distances since it provides consistent and stable
results at any certain distance.
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Results from these tests greatly influenced
which sensors to use for elevator project
We decided to use Because sonar sensor had
such linear and stable results, it as primary
sensor for elevator
Rangefinder had varied results and felt it
would be unreliable for use in project
Didn’t use light sensor either because it had
little use in our design
Unique design: using only one sensor, which is
sonar sensor
 Elevator call buttons were start and stop buttons
on Handyboard
 Group felt we would have a simpler code by using
only one sensor
 While somewhat true, the code became more
complicated to write than initially anticipated
Trials:
- rewrote code several times until got it working
properly.
- had to fine tune timing of the elevator car.
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Design:
- simple and easy to construct and
was reliable in its operation
- streamlined stopping to simply
turning off motor
- enough friction was built into
raising/lowering mechanism to
ensure elevator stayed in place
whenever motor was off
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Work on elevator: mostly Daniel Kattan
Work on elevator code: mostly Stephen Joo
We did a lot of work together to ensure that
physical elevator would work properly with
the code
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Instrumentation lab exposed us to different instruments
used by computer engineers
Oscilloscope used for measuring voltage changing with
time and displays it in graphical format
Voltage displayed as sine wave (if AC current)
Used to display most EM waves
Dials on control panel are manipulated to produce unique
graph shown on display monitor
Input channels allow cables of two distinct functions via
two channels
Oscilloscope includes function generator which can easily
change amplitude, frequency, shape of the graph, and
more
Allows one to see how things should look before testing
his/her circuits
DC power supply source:
- gives varying amounts of power to circuits
- used to supply constant voltage to circuit;
this voltage can be changed to see how circuit
reacts to different voltages
- many of these changes are measured using
oscilloscope
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In another lab, we used breadboard to
build physical circuit and connect it to
DC power supply source for power
We measured voltage, current, and
resistance at different points around
circuit
Lab allowed us to actually see what
we learned in class; by actually
building and measuring the circuits,
we understand better what is going
on
Simulation Program with Integrated Circuit Emphasis:
 used for analog and digital circuit design and educational
purposes
 we designed circuit blueprints via this program by adding
various resistors, capacitors, voltage sources, ground, and
link them all together into uniform circuit
 program allows you to test various circuits to ensure
working design before actually building them
 by building/testing circuit in PSPICE before physically
building it, engineers can try out different designs and
save time and money
The following two images are circuit designs of various
homework problems.
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Learned how to make own
AM radio by soldering and
connecting parts from AM
radio kit
Learned how to solder
correctly
Split up work of soldering
parts evenly between two
of us so both got practice
soldering joints
Once radio was complete,
we could use oscilloscope
to test frequency of
incoming signal.
Problem:
- trouble with larger solder joints
because soldering iron didn’t get
hot enough to melt solder quickly
Solution:
- soon figured out that if we held
soldering iron against joint and
wire for minute or two it heats up
enough to allow solder to flow
evenly over joint
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Would have been helpful to have
different tips for soldering iron
to have greater precision for our
work
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Overall, the projects have helped us become
better engineers and better team players
We encountered many problems faced by
engineers like coordinating the simultaneous
development of hardware and software.
We became better team players through our
need to finish projects outside of classtime