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ECE 3300 Lab 2
ECE 1250 Lab 8 – Sensor System
Name ______________________ Lab Section ___ Homework Folder # ____
Invent a Sensor System
Background:
In previous labs and homework, you have learned to design and use:
 Simulation software (Multisim)
 Electrical test equipment
o DMM (digital multimeter) to measure V,I,R (on your MyDAQ)
o Oscilloscope to measure V as a function of time (on your MyDAQ)
o LED indicators for output voltage (see Labs 1 and 2)
 DC sources (from the MyDAQ) and AC sources (the function generator on your
MyDAQ)
 Resistive sensors
o Potentiometers (for tuning)
o Thermistor (for temperature)
o Light sensor
o Moisture sensor (the home made resistor you created)
 Capacitive sensors
o Any way you can physically change permittivity, area, or distance …
 Op Amp amplifiers, summers, difference amp, buffer (voltage follower)
 Digital circuits (only very brief experience, but these are available for you to use as
well)
 Block diagram approach to designing circuits (‘deck of cards’)
Step-by-Step Instructions:
The Lab 4 ‘extra credit’ section (see p9 of Lab 4) has a step-by-step description of how to
design a simple resistive sensor system. There are also a number of places on the internet
you can find circuits of all kinds. It is ok to use these resources, however you still need
to go through, explain, and write up your design process.
References:
INCLUDE REFERENCES FOR ALL SOURCES YOU USE TO DESIGN YOUR
CIRCUIT. It is appropriately professional to give credit for ideas or information you use
from someone else, and you or someone else are likely to want to go back to find them
again in the future. Please use the IEEE Reference format which is typically used for
electrical
engineering
reports
and
papers
world-wide:
http://www.ieee.org/documents/ieeecitationref.pdf
Overview:
In this lab you will:
Invent a sensor system: Design, simulate, and build a sensor system of your own
devising. Build the circuit to have this sensor sense something in the environment and
then DO something. It can turn on a light, motor, or buzzer, for instance.
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UNIVERSITY OF UTAH DEPARTMENT OF ELECTRICAL AND COMPUTER ENGINEERING
50 S. Central Campus Dr | Salt Lake City, UT 84112-9206 | Phone: (801) 581-6941 | Fax: (801) 581-5281 | www.ece.utah.edu
ECE 3300 LAB 8
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Week 1: Preliminary Design Review (PDR)
NOTE: For safety, your system must stay within the limits of the MyDAQ
voltages and currents.
Choose an R or C sensor to sense some aspect of the physical world (for example,
moisture, temperature, light, etc.).
Decide what your sensor is going to do (turn on a light when the temperature gets too
high, for instance).
Design the block diagram for your sensor.
Describe in reasonable detail what you are going to build, and what will be needed to
build it.
Order any unusual parts needed for your system. For instance, the reference material
on the lab site lists sources for many different types of sensors available. Or you
might choose to use a buzzer or small DC motor instead of an LED for the ‘action’ of
the system.
TURN IN: Preliminary Design Report (PDR): Write up your preliminary design (the
information listed above with enough explanation that another student or TA can
understand what you are planning to do and how you plan to do it). This should be
about 1-2 pages.
o Does your report explain what you are doing in sufficient detail the TA or another
student can understand it?
o Is your block diagram included?
o Are any graphs included and labeled (x,y axes, and captions or titles, include units
if applicable)
o Are any references included, in IEEE format?
Preliminary Design Review: Have a TA review your design with you.
o Is your design feasible?
o Can you do it in the 3-week time frame? Keep it simple. It is always better to
‘promise less and deliver more’. If you have a larger project in mind, carve out a
simple section of a bigger project, or do a simple demonstration of the larger
project for the purposes of this lab. If you accomplish more than you plan in your
PDR, that is fine.
o Is your design useful, cool, creative or interesting in some way? Your final
project will have an extra 50 points for ‘high cool factor’ if you make it creative,
unique, beautiful, useful, or interesting in any way and post a video about your
project.
o Is your project safe? This class has not yet prepared you to work with higher
voltages, so please limit yourself to the voltage and current limits of your
MyDAQ. Don’t do anything that ‘plugs into the wall’.
Week 2: Critical Design Review (CDR)
 Design the circuit diagram for your sensor system: Convert the block diagram from
week 1 to a circuit diagram for week 2. Specify all components (resistors, capacitors,
op amps, etc.)
 Test your sensor (measure it) to be sure it will work as planned. Test the range of
resistance/voltage/current/capacitance/whatever it produces over the range of
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UNIVERSITY OF UTAH DEPARTMENT OF ELECTRICAL AND COMPUTER ENGINEERING
50 S. Central Campus Dr | Salt Lake City, UT 84112-9206 | Phone: (801) 581-6941 | Fax: (801) 581-5281 | www.ece.utah.edu
ECE 3300 LAB 8
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environmental parameters you expect it to measure (such as the range of resistance on
a thermistor for the temperature range you expect). You will need this range of
values for your simulation below.
Simulate your sensor with Multisim and be sure it will work as planned. HINT:
Circuits have an amazing ability NOT to work the first time. If you just simulate it
all together it can be very difficult to debug. Please don’t expect the TAs to look at
your full circuit and magically figure out what is going wrong. It is a really really
really good idea to build up your system one block at a time, testing each block as
you go (in simulation and also later in hardware), so that you catch any mistakes or
problems in each small bit of circuitry rather than trying to debug the whole thing at
once. HINT2: Keep your simulation as simple as you can. If you are simulating a
resistive sensor, for instance, it is Ok to use a potentiometer or to manually change
the value of a resistor to emulate the different states of your sensors in the simulation.
Check (in simulation) that the voltages and currents within the circuit are within spec
for all of the parts you are using.
TURN IN: Critical Design Report (CDR): Add the information from your sensor test,
system simulation, and check that you will be within spec to the PDR write up you
did in week 1. This should be about 2-4 pages.
 Does your report explain what you are doing in sufficient detail the TA or
another student can understand it?
 Have you included your sensor test data?
 Is your system diagram included? (Ok to copy from Multisim)
 Have you included the output from simulation, showing that the system will
work as planned? And that it will be within spec for all parts?
 Are any graphs included and labeled (x,y axes, and captions or titles, include
units if applicable)
 Are any references included, in IEEE format?
Critical Design Review (CDR): Demonstrate your simulation to a TA and have them
sign off on it.
Week 3: Final Design Review (FDR)
 Build & Test your circuit. HINT: To make this easier to debug, build and test
individual circuit blocks separately. Build your circuit up in little pieces, testing as
you go.
 TURN IN: Final Design Report (FDR): Add the information from your final build
and test to the CDR write up you did in week 2. This should now be about 4-6 pages.
o Include your design and build information, a PHOTO of your circuit, a
description and test data for how the circuit performed in the end.
o Any graphs should be labeled (x,y axes, and captions or titles, include units)
o References should be in IEEE format.
 Final Design Review (FDR): Demonstrate your working circuit to a TA and have
them sign off on it. If you are sensing something that is not easily brought in to the
lab, video your demonstration at home/work.
 Extra Credit (50 points): If your design is useful, cool, beautiful, creative or
interesting? Up to 50 points extra credit if you make and post a video about your
project (upload to Canvas or include a YouTube link).
3
UNIVERSITY OF UTAH DEPARTMENT OF ELECTRICAL AND COMPUTER ENGINEERING
50 S. Central Campus Dr | Salt Lake City, UT 84112-9206 | Phone: (801) 581-6941 | Fax: (801) 581-5281 | www.ece.utah.edu
ECE 3300 LAB 8
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Equipment and Parts:
The ECE stockroom carries all standard resistors, LEDs (all different colors), capacitors,
potentiometers, digital components, etc. I have asked them to order some small buzzers
you can use in place of LEDs.
Other places you can order special components, additional types of sensors, etc:
o Radio Shack
o digikey.com
o alliedelec.com
o jameco.com
o newark.com
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UNIVERSITY OF UTAH DEPARTMENT OF ELECTRICAL AND COMPUTER ENGINEERING
50 S. Central Campus Dr | Salt Lake City, UT 84112-9206 | Phone: (801) 581-6941 | Fax: (801) 581-5281 | www.ece.utah.edu
ECE 3300 LAB 8
ECE1250 Invent a Sensor System Cover Sheet
Turn this in each week with your report. By the end of the project it will be all filled
in.
Name _____________________________________
Homework Locker # _______
Lab section ________
Points: Each week’s sign off is worth 50 points. The associated paper you turn in is also
worth 50 points.
Week 1: Preliminary Design Review (TA sign off : ____________________________)
_____ Is your design feasible?
_____Can you do it in the 3-week time frame? Keep it simple. It is always better to
‘promise less and deliver more’. If you have a larger project in mind, carve out a simple
section of a bigger project, or do a simple demonstration of the larger project for the
purposes of this lab. If you accomplish more than you plan in your PDR, that is fine.
______Is your design useful, cool, creative or interesting in some way? Your final
project will have an extra 50 points for ‘high cool factor’ if you make it creative, unique,
beautiful, useful, or interesting in any way and post a video about your project.
______Is your project safe? This class has not yet prepared you to work with higher
voltages, so please limit yourself to the voltage and current limits of your MyDAQ.
Don’t do anything that ‘plugs into the wall’.
Week 2: Critical Design Review (TA sign off : ______________________________)
_____ Sensor test data shows sensor works as planned.
_____ Multisim shows system design will work.
_____ System design is within spec for all parts.
Week 3: Final design Review
(TA sign off : ______________________________)
_____ System works as planned! OR Video your project working and turn that in.
Extra Credit (up to 50 points): If your design is useful, cool, beautiful, creative or
interesting? Up to 50 points extra credit if you make and post a video about your project
(upload to Canvas or include a YouTube link).
Points:
Week 1: PDR
Week 2: CDR
Week 3: FDR
Extra Credit Video
TA sign off on hardware and/or Write up
simulation (above)
(out of 50 points)
(out of 50 points)
(up to 50 points)
5
UNIVERSITY OF UTAH DEPARTMENT OF ELECTRICAL AND COMPUTER ENGINEERING
50 S. Central Campus Dr | Salt Lake City, UT 84112-9206 | Phone: (801) 581-6941 | Fax: (801) 581-5281 | www.ece.utah.edu