PC/CP320 Physical Computing: Digital Interaction with the Analog World


Fall term course



This is the Physics/Computing 320 Lab page, prepared by Terry Sturtevant .
Page last updated Monday January 9, 2023
**Items marked this way are not final.**


Week 1, Week 2, Week 3, Week 4, Week 5, Week 6, Week 7, Week 8, Week 9, Week 10, Week 11, Week 12

Introduction

Useful links

Evaluation Methods

Course Material

Week of ... Lab / Lecture Reference Material
[white background indicates required reading;
gray background indicates optional reading]
 

Jan. 9
Lecture: Introduction, resistors and resistance
  1. Course Introduction: What's the purpose of PC/CP320? [PDF]   [ September 5, 2018 ]
    Course syllabus     [ December 14, 2021 ]

  2. Active Learning Introduction
    Proven teaching strategies

  3. Overview of Physical Computing   [ September 8, 2017 ]

  4. Learning on your own using Google and YouTube, etc.

  5. Block Diagrams   [ February 13, 2019 ]
    Block Diagram Elements [HTML]   [ November 9, 2017 ]
    Block Template
    Signals for block diagrams library for Dia
    Use this if you are installing Dia on your own computer.

    draw.io online drawing app
    Sample signals

  6. Electrical terminology   [ September 8, 2016 ]
  7. Resistors and resistance   [ September 7, 2017 ]

    colour code humour

    colour code snake humour
  8. Variable Resistors (Trimmers)   [ January 4, 2018 ]

Lecture: Single board computers including the Raspberry Pi
  1. Single board computer platforms   [ November 23, 2016 ]

    Arduino, Pi model B+
    Pi model A, B, B+
    Pi 2, model B+
    Pi 3, Pi 2, model B+
    Arduino, Pi model B, BeagleBone
    Raspberry Pi models comparison
    arduino symbol

    raspberry pi symbol

  2. Linux shell command summary
    Note: Linux is case-sensitive, and commands should be in lower case.
  3. Raspberry Pi GPIO pins
    Board and Broadcom numbering schemes
    WEMOS GPIO pin guide
    Note that numbering uses the Broadcom system. How can you tell?

    Orientation of GPIO pins
    Correct cobbler orientation
    GPIO orientation
  4. Access GPIO from Linux user space

    Tip: To see the Pi internal temperature, type:
    cat /sys/class/thermal/thermal_zone0/temp
    Divide the result by 1000; e.g. 44250 corresponds to 44.25 Celsius.

  5. Identifying resistor nominal values (ALC exercise)
    When there isn't an integer middle value, choose the nearest integer below the middle.
    doc version
    png version
    Timer (6 minutes)

  6. Digital multimeters   [ November 7, 2018 ]

  7. Using lab notebooks
    New Information: Lab Notebook summaries   [ May 12, 2017 ]
    Summary checklist   [ January 18, 2017 ]
    "summarization is among the top nine most effective teaching strategies in the history of education"

  8. 5 minutes more??
Lecture: Electrical circuits

xkcd comic

  1. Kirchhoff's laws   [ May 16, 2011 ]
  2. Kirchhoff's laws example   [ May 31, 2017 ]
  3. Voltage dividers   [ May 31, 2017 ]
    voltage divider symbol
  4. Application of voltage dividers - internal resistance   [ June 13, 2014 ]
  5. Determining battery internal resistance (ALC exercise)
    Timer (6 minutes)

  6. Review: Breadboards [PDF]   [ May 1, 2012 ]

  7. Quiz during next lecture!
  8. Online Quiz: Read over the learning objectives for this course.
    Do quiz on MyLearningSpace between 7 a.m. Friday and 11:30 p.m. Sunday evening.
    "Our central result is that higher exposure to the online instrument robustly leads to higher student learning, all else being equal."


 
  • Safety - Emergency Numbers   [ April 29, 2015 ]

  • Lab A: Resistors and Ohmmeters
  • Lab B: Lab Summary Writing Exercise
  • Postlab Requirements: Writing a lab summary   [ May 12, 2017 ]
    Summary checklist   [ January 18, 2017 ]

  • After this week's lab, you know how to use a digital multimeter to measure resistance, to read resistor colour codes, and to identify specific Raspberry Pi GPIO pins.

  • Before next lecture: Watch this video!

    Water analogy [screencast]
    water analogy


Resistance
[© 1995-2003 M. W. Davidson, Florida State University]

Fixed Resistors   [ January 8, 2018 ]
Measuring Resistance   [ May 12, 2017 ]
Measuring Continuity   [ May 12, 2017 ]


Resistor colour coding chart
[PDF; NIC Components, May 2004]

Which Way Does Current Really Flow?

Resistor colour codes: 4- band, 5- band
[GIF; © 1996-2003 Electronix Express]
Resistor colour code: 4, 5, 6 band
[JPG; T. May, University of Colorado]
[PDF 50pp, © Wavetek Meterman, 2000]
Wavetek Meterman 33XR Operator's Manual
[PDF 17pp, © Amprobe,]

MAKE presents: The Resistor
the resistor

Resistors [from PC200]
Resistor colour code: 4, 5, 6 band
[JPG; T. May, University of Colorado]
 

Jan. 16
Lecture: Raspberry Pi GPIO pins and Python programming on the Raspberry Pi
  1. GPIO access in Python
    Official RPi.GPIO Wiki examples
  2. GPIO access in Python
    Raspberry Pi GPIO pins
    Basic python example
    Modified python example
    Broadcom numbering example
    Another board numbering example
  3. Good Coding Style   [ August 23, 2018 ]
    Why magic numbers are evil
    Unnamed numerical constants

    code 
quality

    code 
quality 3

    Coding without comments
    Code Style Checklist [PDF]   [ January 18, 2017 ]

  4. Voltage, current and Ohm's law quiz
    Timer (6 minutes)

    Applying some basic concepts of voltage, current, and power
    Rationale for collaborative quizzes
    "The students first completed a quiz individually. Once the quiz was completed individually, the students completed the same quiz in groups. Eighty percent of the score on the quiz was based on the individual results, and 20% of the score on the quiz was based on the group results. The performance on the quizzes was significantly higher when students completed the quizzes in groups than when they completed the quizzes individually. Results document that completing the quizzes in groups enhances the understanding of the material."

  5. Resistive sensors   [ May 31, 2017 ]
    force-dependent resistor
    photoresistor
    thermistor
    strain gauge

Lecture: Maker Lab Introduction
  1. Launchpad Science Maker Lab Introduction

Lecture: Voltage considerations for Raspberry Pi GPIO pins and exploration project introduction
  1. Review of previous quiz q1
    Groups with 5 had 1 or 2 people who had it perfect individually!
    Only 3 (out of 6) groups had anyone go down due to group mark.
    To figure out group mark:
    Since FINAL = 0.8 INDIVIDUAL + 0.2 GROUP
    GROUP = (FINAL - 0.8 INDIVIDUAL) / 0.2


  2. good lab summary
    Clear, useful, and just 1 page

  3. Logic family characteristics - voltage   [ May 23, 2018 ]
    Logic gate characteristics - measuring voltage limits   [ November 20, 2014 ]
  4. GPIO Electrical specifications
  5. Determining GPIO voltage limits (ALC exercise)
    Timer (6 minutes)

  6. Exploration Project Overview   [ May 24, 2018 ]
    Exploration project introduction
    Remember Google, YouTube, etc.
    Example of wrong/misleading "data"
    Exploration Project checklist

  7. Replace/get credit for a lab summary
    Go to the Science Maker Space and do the introduction and I'll count it in place of one lab summary.

  8. Enclosure project overview [PDF]   [ October 24, 2019 ]
    Enclosure Project checklist [PDF]   [ October 23, 2019 ]

  9. Quiz during next lecture!
  10. Online Quiz: Review proper electrical terminology.
    Do quiz on MyLearningSpace between 7 a.m. Friday and 11:30 p.m. Sunday evening.



Electrical Circuits Review [pdf 18pp; B. M. Fleischer] - sections B.1 and B.2.1 

Operating point analysis in CircuitLab [video]
operating point analysis in CircuitLab


Internal resistance of a voltage source [screencast of PDF]
internal resistance of a voltage source

Voltage Divider [© 2000, C.R. Nave, Georgia State University]

Potentiometers [video]
potentiometers

Voltage dividers [video]
voltage dividers


 

Measuring DC Voltage   [ May 12, 2017 ]
Measuring DC Current   [ May 12, 2017 ]

Lab bench setup in N2082 [video]
lab bench setup in N2082


Dual DC supplies [video]
dual DC supplies




Voltage Circuit Simulator   [java applet; G. Bothune, UOregon]



MAKE presents: Ohm's Law
Ohm's law
 

Jan. 23
Lecture: Producing and measuring analog signals
  1. Active learning research result
    Measuring actual learning versus feeling of learning in response to being actively engaged in the classroom
    "Comparing passive lectures with active learning using a randomized experimental approach and identical course materials, we find that students in the active classroom learn more, but they feel like they learn less. We show that this negative correlation is caused in part by the increased cognitive effort required during active learning."

  2. Note different postlab requirements this week!

  3. Oscilloscopes   [ August 23, 2018 ]
    oscilloscope symbol

    Triggering on an oscilloscope
    oscilloscope triggering
  4. Function generators   [ January 20, 2020 ]

    function generator symbol
  5. Simple DC circuits quiz
    Simple application of Kirchhoff's laws
    Timer (6 minutes)

Lecture: Diodes, including Zener diodes and photodiodes
  1. Reading data sheets   [ May 12, 2017 ]
  2. Reading data sheets   [ October 7, 2013 ]
    sample datasheet (Fairchild)
    sample datasheet (National Semiconductor)
    sample datasheet (International Rectifier)
    sample datasheet (Photonic Detectors)


  3. Diodes [PDF]   [ September 9, 2015 ]
    Diode Measurement  [ May 1, 2014 ]

    diode operation humour

  4. Zener Diodes and Photodiodes [PDF]   [ September 26, 2017 ]
  5. Selecting Zener/photodiode resistors (ALC exercise)
    1N525B Zener diode, ON Semiconductor; determine resistor for 12V supply
    Note recommended vs. maximum current.

    SFH 229 Photodiode, Osram Semiconductors; determine resistor for 12V supply and 3.3V swing with light
    Save these results and you'll save time in the lab!
    Timer (6 minutes)

  6. Sketching AC signals   [ April 19, 2011 ]

Lecture: Optical Isolation and more electrical considerations for GPIO pins
  1. Review of previous quiz q2
    One group with 10/10 had highest individual of 4/10.
    One group with 10/10 had highest individual of 5/10.
    To figure out group mark:
    Since FINAL = 0.8 INDIVIDUAL + 0.2 GROUP
    GROUP = (FINAL - 0.8 INDIVIDUAL) / 0.2
    GROUP = 5X (FINAL - 0.8 INDIVIDUAL)


  2. Note postlab requirements

  3. Optical Isolation [PDF]   [ November 10, 2016 ]
    optoisolator symbol
  4. Optoisolator Calculations [PDF]   [ October 1, 2018 ]

  5. Selecting LED/photodiode resistors for optoisolator(ALC exercise)
    PS2501 datasheet
    determine resistors for 5v on input and output at least 2.5V with a 3.3V supply
    determine resistors for 3.3v on input and output at least 4V with a 5V supply
    Save these results and you'll save time in the lab!
    Timer (10 minutes)

  6. Optoisolator breadboard layout [PDF]   [ November 16, 2017 ]

  7. Lab notes (optoisolator)
    scope output
    circuit
    triangle wave output
    increased output resistor value

  8. Quiz during next lecture!
  9. Online Quiz: Review Kirchhoff's laws and their application.
    Do quiz on MyLearningSpace between 7 a.m. Friday and 11:30 p.m. Sunday evening.




Logic Gates
logic gates created from discrete components
Measuring Strain with Strain Gages  [© 2016 National Instruments Corporation]
Logic Family Selection Guide


 
Overtones, harmonics, and additive synthesis [video]
overtones, harmonics, and additive synthesis

DC and AC voltage measurements with an oscilloscope
DC and AC voltage measurements with an oscilloscope

Finding the origin on an oscilloscope in XY mode
finding the origin on an oscilloscope in XY mode

Use of a function generator - Part I
use of a function generator (1/2)

Use of a function generator - Part II
use of a function generator (2/2)


MAKE presents: The Oscilloscope
oscilloscopes



Close-up pictures of signal generators we have in the lab:
White case model (Instek GFG-8217A)
Black case model (Wavetek FG3C)
Grey case model (Wavetek FG3B)
Old model (Wavetek 182A)

XYZ's of Signal Sources [pdf 52pp; © 2005, Tektronix, Inc.]

Philips oscilloscope (PM3207)

XYZ's of Oscilloscopes [pdf 64pp; © 2001, Tektronix, Inc.] The Cathode Ray Oscilloscope [pdf 6pp, T. Sturtevant]
TDS1000 and TDS2000 Series Digital Storage Oscilloscopes [© Copyright Tektronix, Inc.]
TDS210 Series Digital Storage Oscilloscopes [© Copyright Tektronix, Inc.]

ABCs of Probes [pdf 48pp; © 2005, Tektronix, Inc.]
Oscilloscope animation (Flash)
 

Jan. 31
Lecture: Capacitors; output transducers (actuators) and how to control them using the Raspberry Pi
  1. Logic gate characteristics - current   [ September 4, 2013 ]
    Logic gate characteristics - measuring current limits   [ September 4, 2013 ]
    datasheets for SN7400, CD4011UB, 74HC00A

  2. The Embroidered Computer

  3. Capacitors   [ October 9, 2015 ]
  4. Identifying Capacitor Polarity  [ August 22, 2019 ]

  5. Oscilloscope quiz
    Basic functionality of the oscilloscope
    Timer (6 minutes)

  6. Inductive Output Transducers [PDF]   [ October 18, 2016 ]
    pmdc motor symbol
    brushless motor symbol
    servo motor symbol
    stepper motor symbol
Lecture: Conversions between analog and digital signals and the SPI interface on the Raspberry Pi
  1. Review of previous quiz q3
    Group with 4/10; both got higher individually!
    Two groups that got 10/10 had all individual marks lower.

  2. Analog and Digital Quantities [PDF]   [ May 25, 2017 ]
    ADC symbol
    DAC symbol
  3. Analog to Digital and Digital to Analog Conversion [PDF]   [ October 3, 2018 ]

    A/D converter demonstration [video]
    A/D converter demonstration

  4. Analog and Digital Grounds and Decoupling Capacitors [PDF]   [ May 31, 2017 ]
  5. Serial Communication-SPI [PDF]   [ October 3, 2018 ]

    SPI symbol
  6. Equating SPI GPIO pins and MAX522 pins (ALC exercise)
    MAX522 SPI digital-to-analog converter
    Supply requirements?
    Save these results and you'll save time in the lab!
    Timer (6 minutes)

  7. Determining MAX522 command words (ALC exercise)
    Note "No Operation" and "All DACs Active" commands.
    What needs to be sent (in Hex) to:
    • Shutdown DAC A
    • Shutdown DAC B
    • Load DAC A with a value of 2 (decimal)
    • Load both DACs with a value of 32 (decimal)
    • Shutdown both DACs

    SPI DAC symbol
    MAX522 SPI python example
    Save these results and you'll save time in the lab!
    Timer (6 minutes)

Lecture: More analog to digital conversion and the SPI interface on the Raspberry Pi
  1. Note different postlab requirements this week!

  2. Identify decoupling capacitors in circuits
    circuit1
    circuit2
    circuit3

  3. MCP3008 SPI analog-to-digital converter

  4. Equating SPI GPIO pins and MCP3008 pins (ALC exercise)
    Save these results and you'll save time in the lab!
    Timer (6 minutes)


  5. MCP3008 SPI python example
    New
    MCP3008 Communication explained [PDF]   [ January 30, 2019 ]


  6. Determining MCP3008 command words and data format (ALC exercise)
    MCP3008 SPI analog-to-digital converter
    Supply requirements?
    What change do you need to make to ADC code to have both DAC and ADC connected at the same time?
    SPI ADC symbol
    Save these results and you'll save time in the lab!

    MCP3008 SPI python example
    Timer (6 minutes)

  7. New
    DC motor with shaft encoder [PDF]   [ November 1, 2018 ]

    pmdc motor with shaft encoder symbol

  8. Controlling Output Transducers [PDF]   [ November 10, 2016 ]

  9. New: H-Bridges and DC Motors [PDF]   [ April 22, 2019 ]
  10. Straw poll 1

  11. Quiz during next lecture!
  12. Online Quiz: Review oscilloscope operation.
    Do quiz on MyLearningSpace between 7 a.m. Friday and 11:30 p.m. Sunday evening.



Diode Measurement [screencast of PDF]
diode measurement


MAKE presents: The Diode
the diode



Checking Diodes   [ May 12, 2017 ]
Physics of a Diode [©2003 Marvin Casanova ]

Measuring Capacitance   [ May 12, 2017 ]
How Capacitors Work [© 1998 - 2003 HowStuffWorks, Inc.]
Charging and Discharging A Capacitor [© 1995-2003 M. W. Davidson and The Florida State University]

Identifying Capacitor Polarity [screencast of PDF]
capacitor polarity


MAKE presents: The Capacitor
the capacitor


Tristate Buffers
tri-state buffers



Introduction to Wired-OR Outputs and Open-Collector Circuits   [© 2003 National Instruments Corporation]
7401 datasheet   [© 1995 National Semiconductor]

Design Fundamentals for Phototransistor Circuits   [ April 30, 2015 ] [© 2002 Fairchild Semiconductor]


Stepper, servo, DC motor control [video]
stepper, servo, DC motor control


How does a Stepper Motor work ? [video]
stepper motor construction

Induced EMF demo from MIT [video]
induced EMF demo from MIT

Induced EMF in a motor [video]
induced EMF in a motor

Relays and Optocouplers [video]
relays and optocouplers

Small solenoid operation [video]
small solenoid operation

What is a solenoid valve? [video]
solenoid valve


How do servos work? [video]
how servos work


MOSFET tutorial [video]
MOSFET tutorial


MOSFETs and How to Use Them [video]
Another MOSFET tutorial

Transistor as a switch [video]
transistor as a switch

SSRs Technical Information [PDF 8pp; © Copyright Matsushita Electric Works, Ltd.]
Solid State Relays [PDF 5pp; Vishay, 2001]
 
  • Lab A: Zener Diodes and Photodiodes  [ November 15, 2017 ]

    Note: If you finish early, start on Lab B.

  • Lab B: Optical Isolators  [ January 30, 2020 ]
    PS2501 datasheet
    Note: Don't take this circuit apart after the lab; you'll be using it later.
  • Postlab Requirements: Show your calculations for the required resistors for the Zener diode and for each optoisolator.
    Diode calculation checklist   [ May 16, 2019 ]


  • After this week's labs, you know how to get inputs from the outside world at any specified voltage into the Raspberry Pi and you know how to provide outputs to the outside world at any specified voltage from the Raspberry Pi .

HC-SR04
HC-SR04 datasheet
Optoisolator simulation [video]
optoisolator simulation


Analog Optical Isolators VACTROLS® [©1998-2004. PerkinElmer, Inc.]
 

Feb. 7
Lecture: More logic gate I/O options
  1. Straw poll results

  2. Logic gate characteristics - propagation delay   [ November 16, 2016 ]

  3. Logic gate characteristics: Open collector and open drain outputs   [ October 3, 2018 ]
    datasheet for SN7401
  4. Zener diode quiz
    Choosing correct resistors
    Timer (6 minutes)

  5. Logic gate characteristics: - Tri-state outputs   [ June 1, 2017 ]
    Processor internal architecture
    "Standard" Processor internal architecture
    Z80 system architecture (outside mpu)
    Hyperphysics microprocessor page


  6. GPIO Electrical Specifications
    Note tri-state section
Lecture: Static sensitive devices


  1. Static discharge   [ February 18, 2010 ]

    ESD video (2/4)
    ESD video (2/4)
    ESD video (3/4)
    ESD video (4/4)
    ESD prevention measures
  2. GPIO Electrical Specifications
    Note diode section

Lecture: Using operational amplifiers to modify analog signals
  1. Review of previous quiz q4
    Only 1 person went down.
    One 8/10 group had all 3 people go up.
    Only group problem was drawing the circuit.

  2. Operational Amplifier Basics [PDF]   [ October 4, 2016 ]

    Rails of an operational amplifier [video]
    op amp rails

    op amp symbol
    Optoisolators allow changes in voltage for digital signals; op amps allow changes in voltage for analog signals
  3. Noting variation in naming conventions (ALC exercise)
    sample 1
    sample 2
    sample 3
    Timer (4 minutes)

  4. Operational Amplifier Circuits [PDF]   [ September 4, 2014 ]

  5. Analog computers [video]
    analog computers


  6. Sketching amplifier output [PDF]   [ September 7, 2013 ]
  7. Sketching op amp circuit output (ALC exercise)
    circuit 1
    This is what you'll do in a future quiz!
    Timer (6 minutes)

  8. Quiz during next lecture!
  9. Online Quiz: Review optoisolator operation.
    Do quiz on MyLearningSpace between 7 a.m. Friday and 11:30 p.m. Sunday evening.


ADC and DAC Glossary [HTML; PDF] [Dallas Semiconductor, 2000]

A/D converter simulation [video]
A/D converter simulation




 

Sensors and Signal Conditioning Overview  [ May 12, 2017 ]
Solenoid Catalog [ © 1999, 2000 Magnetic Sensor Systems ]


Animations:
 

Feb. 13
Lecture: Operational amplifiers, Wheatstone bridges and their applications for analog sensors and signals
  1. Negative Feedback in Operational Amplifiers [PDF]   [ July 29, 2013 ]

  2. Operational Amplifier Dynamic Response [PDF]   [ October 9, 2015 ]
  3. Neat animations of op amp circuits

  4. Output transducer quiz
    Considerations for controlling output transducers
    Timer (4 minutes)

  5. Wheatstone bridge circuits   [ October 18, 2016 ]

  6. Wheatstone bridge animation

    electricity humour

  7. Use of Differential Amplifier Circuits [PDF]   [ February 8, 2019 ]

  8. Analog Sensors [PDF]   [ October 19, 2018 ]
    analog sensor symbol
    Infrared distance sensor - GP2Y0A21YK
    Photodiode - sfh229
    Hall sensor - 3503
    Capacitive soil moisture sensor
    Resistive soil moisture sensor
    Pulse rate sensor
    Pulse rate sensor (back)
    sensor interfacing

Lecture: Serial interfaces which various devices use to communicate with the Raspberry Pi
  1. Look at completed learning objectives

  2. Serial communication (UART)
    Serial Communication-UART [PDF]   [ November 7, 2018 ]

    UART symbol
    If using serial (i.e. UART) sensors, you need to turn off the serial console and feed both signals through the appropriate optoisolators (to and from the Pi).
    Here's the rpi-serial-console script.
    To turn off the serial console:
    sudo rpi-serial-console disable
    To turn on the serial console:
    sudo rpi-serial-console enable


  3. UART devices
    GPS module, RFID reader, Bluetooth module

  4. I2C interface
    Serial Communication-I2C [PDF]   [ February 13, 2019 ]
    Devices come with a default address programmed in, but it can usually be changed.

    I2C symbol
  5. I2C devices
    digital compass (HMC6352), colour sensor (ADJD-S371), light intensity sensor (GY-30), 3-axis magnetometer (HMC5883L), gyro (ITG-3200), 128x32 OLED display

  6. Determining GPIO current limits (ALC exercise)
    Find all of the rules governing current limits.
    GPIO Electrical Specifications


    Timer (6 minutes)

  7. More Good Coding Style   [ October 3, 2018 ]

    Programming tips

  8. Straw poll 2

Lecture: Single wire interfaces
  1. Review of previous quiz q5
    Only 1 person went down.

  2. Straw poll 2 results (overall)
    Straw poll 2 results (breakdown)

  3. Single Wire Communication
    Single Wire Interfaces [PDF]   [ October 23, 2017 ]

    1 wire symbol
    single wire interface symbol

  4. Identifying interfaces (ALC exercise)
    Sample interfaces
    Timer (6 minutes)

  5. Three options for connecting to devices:
    • Use existing Python libraries
    • Use system commands from within Python (if there aren't specific Python libraries)
    • Bit-bang your own interface in Python

    Bit banging [PDF]   [ February 13, 2019 ]
    Bit banging on Wikipedia
    Raspberry Pi Interface with Parallax Serial RFID Reader
    Bit-banged serial interface [to RFID reader]
    bit-banging in action


    Bit-banged SPI Interface to MCP3008

  6. Quiz during next lecture!
  7. Online Quiz: Review op amp introduction
    Do quiz on MyLearningSpace between 7 a.m. Friday and 11:30 p.m. Sunday evening (at the end of Reading Week).






Analog computers [video]
analog computers


Op amp tutorial [video]
op amp tutorial

Low pass filter operation [video]
low pass filter operation


Wheatstone Bridges: Introduction [©2003 eFunda; Engineering Fundamentals]
Wheatstone Bridge Animation [screencast of animation]
Wheatstone bridge

Measuring Strain with Strain Gauges [©2005 National Instruments Corporation]

 
 

Four bus breadboards [video]
four bus breadboards




Op amps compared (including open collector) [video]
op amps compared (including open collector)
 

Feb. 20
Lecture: More different devices and how they interface with the Raspberry Pi
  1. Success versus completion (Winter 2019)
    This ignores 45% of the grade (projects and online).
    It ignores performance.

  2. Row-Column Devices [PDF]   [ February 13, 2019 ]
    Wiki sections on "more than one channel" and "several channels"
    Also note options for enabling pull-up or pull-down resistors.
    row-column display symbol

  3. Row-Column with Both Outputs and Inputs
    row-column keypad symbol

  4. Operational Amplifier Circuit quiz
    Functionality of common op amp circuits
    Timer (6 minutes)

  5. Matrix LCD Driver (MAX7219) [PDF]   [ February 13, 2019 ]
    MAX7219 datasheet

    MAX7219 8x8 LED matrix
    MAX7219 8 digit 7 segment display

  6. TM1638 datasheet (LED/Keypad controller)
    TM1638 key/display board

    TM1637 datasheet (LED/Keypad controller)
    TM1637 display board (front)
    TM1637 display board (back)

Lecture: Project Explanation and PWM devices
  1. Review of previous quiz q6
    Top 2 groups realized it was non-inverting.
    Top 4 groups realized output would hit rails.

  2. Response-time sensors; shaft encoders and ultrasonic sensors
    Pulse Width Modulation Communication [PDF]   [ August 14, 2020 ]

    Note: On the Raspberry Pi 2, there are 4 possible PWM pins:
    • BCM GPIO 18 (using PWM0, so same as GPIO 12)
    • BCM GPIO 12 (using PWM0, so same as GPIO 32)

    • BCM GPIO 13 (using PWM1, so same as GPIO 33)
    • BCM GPIO 19 (using PWM1, so same as GPIO 35, and also is SPI1_MISO, so won't be available if SPI1 in use)

    SR04 Ultrasonic range finders

    SR04 ultrasonic distance sensor signals

    pulse width measurement code

    ultrasonic sensor symbol

  3. Project overview
    Outline of all 3 projects [PDF]   [ October 23, 2019 ]
    Note: DC motor needs 1 channel of shaft encoder connected to indicate position.
    DC motor being able to run in both directions and monitor both channels for speed and direction can be a substitution project and the second channel can replace the other input.
    If the TM1638 board is used for input and output, it can replace the second input for the integration project.

    Outline of integration project [PDF]   [ February 22, 2019 ]
    Integration project options [PDF]   [ February 21, 2020 ]


    Outline of exploration project [PDF]   [ October 24, 2019 ]

    Option: test (and document) my Fritzing board
    my 
fritzing 
board (front)
    Back of populated board
    Board overview

    Outline of enclosure project [PDF]   [ October 24, 2019 ]

    Integration Project checklist [PDF]   [ January 3, 2019 ]
    One output can be a "monitoring voltage" or an LED of varying brightness.

    Exploration Project checklist [PDF]   [ October 23, 2019 ]


    Enclosure Project checklist [PDF]   [ October 23, 2019 ]
    If you're going to do the enclosure project, you have to start ASAP.

  4. Block Diagrams   [ February 13, 2019 ]
    Block Diagram Elements [HTML]   [ November 9, 2017 ]
    Block Template
    Create one of these for each device you use.

    Signals for block diagrams library for Dia
    Use this if you are installing Dia on your own computer.

    draw.io online drawing app
    Sample signals

  5. Raspberry Pi Interface to 28BYJ-48 Stepper Motor

  6. My examples and previous projects

  7. Some output device options
    LTP-1415AG Single colour 8x5 display
    LTP-2558A Tri-colour 8x5 display
    Alphanumeric 16 segment LED display

    New! Digital potentiometer
    (front view)
    (back view)
    X9C103S datasheet

  8. MAX7219 Fritzing Board
    fritzing board

  9. LED Strings [PDF]   [ January 3, 2019 ]
    WS2812B datasheet
    Ring LED (front view)
    Ring LED (back view)

    APA102 datasheet
    SK9822 datasheet

  10. I2C devices
    digital compass (HMC6352), colour sensor (ADJD-S371), light intensity sensor (GY-30), 3-axis magnetometer (HMC5883L), gyro (ITG-3200), 128x32 OLED display

  11. Some input options
    capacitive hex keypad
    TM1638 key/display board
    Telephone keypad

  12. Choosing project components
    Device selection

Lecture:
Software and hardware issues with physical computing
  1. Interrupts and threading [PDF]   [ October 30, 2017 ]
    Interrupts on Wikipedia
    Threading on Wikipedia
    Interrupts on the Raspberry Pi with Python

  2. Real Time Programming   [ November 29, 2017 ]

  3. Three options for connecting to devices:
    • Use existing Python libraries
    • Use system commands from within Python (if there aren't Python libraries)
    • Bit-bang your own interface in Python

  4. Signal Conditioning [PDF]   [ May 30, 2017 ]
    comparator symbol
    analog multiplexer symbol
    one shot multiplexer symbol
    switch symbol

  5. Internet of Things [PDF]   [ March 6, 2019 ]
    "Hackers used 'internet of things' devices to cause Friday's massive DDoS cyberattack" - AP, Oct 22, 2016

    "'A window into your life': Why smart home devices might be putting your privacy at risk" - CBC Sept. 28, 2018

    "Google says it forgot to mention there's a mic in its home alarm system Nest" - CBC Feb. 20, 2019

  6. Quiz during next lecture!
  7. Online Quiz: Review op amp circuits.
    Do quiz on MyLearningSpace between 7 a.m. Friday and 11:30 p.m. Sunday evening.



Permanent magnet DC motor with shaft encoder [video]
DC motor with shaft encoder illustration




Normal servo operation - effect of pulse width [video]
servo motor control


Continuous rotation servo - effect of pulse width [video]
servo motor control (continuous rotation)

Servo Operation and Calibration LM7805 Voltage regulator
LM7805 Voltage regulator datasheet (includes TAB package)
Circuit Integrity - Bypassing [© 2002 Williamson Labs]
Circuit Integrity - Decoupling [© 2001 Williamson Labs]

How a smartphone knows up from down
How a smartphone knows up from down


 


READING WEEK

Feb. 20 READING WEEK - No lecture or labs
 

Mar. 7
Lecture: Doing your own physical computing with the Raspberry Pi
  1. Second SPI channel (SPI1)
    Enabling SPI1 on the Raspberry Pi B+/Zero/2/3

  2. Prototyping options for the Raspberry Pi
    Prototyping options [PDF]   [ October 19, 2018 ]


  3. Diode and capacitor quiz
    Behaviour of diodes and capacitors in circuits
    Timer (6 minutes)

  4. AB Electronics expansion hats

  5. Extending ports with 74HC595 and 74HC589A shift registers
    74HC595 using SPI
    74HC595 with bit-banging
    74HC589A using SPI

  6. Where to get Pi stuff:
    Canada
    USA
    Ebay.ca
    • makervault, universal-solder, and more


  7. Sensors
    Seeed studio
    Grove sensors
    DF Robot sensors

  8. Fritzing design software
    Fritzing Example [PDF]   [ October 24, 2018 ]


  9. Design as a process
    Practical design example [PDF]   [ June 23, 2016 ]


  10. Sensor and actuator inventory   [ November 30, 2017 ]


    If using serial (i.e. UART) sensors, you need to turn off the serial console and feed both signals through the appropriate optoisolators (to and from the Pi).
    Here's the rpi-serial-console script.
    To turn off the serial console:
    sudo rpi-serial-console disable
    To turn on the serial console:
    sudo rpi-serial-console enable
Lecture: Advanced Raspberry Pi physical computing options
  1. No post-lab requirements this week! (But if you hand one in it can make up for a missed one.)

  2. Results of previous quiz q7
    3/4 of groups had 1 individual all or mostly right.
    2 of those groups had results reversed.

  3. Course review
    Has it all been covered?

  4. Reviewing learning objectives (ALC exercise)
    Timer (4 minutes)

  5. Lab schedule

  6. Project components - voltage regulators

    voltage regulators

    We have 5V and 3.3V regulators in the lab.

  7. Pigpio libraries
    These use a daemon process running in a separate thread to bit-bang more ports.

  8. Java on Raspberry Pi
    Pi4J Project GPIO access in Java for the Raspberry Pi

  9. Bluetooth
  10. Near Field Communication (NFC) and RFID
    PN532 module

  11. Arduino and the Wiring language
    Arduberry Arduino-compatible Raspberry Pi interface board
  12. Firmata protocol
    Firmata on Raspberry Pi

  13. Reading analog resistance values without an ADC
    Using Resistive Sensors

    (While this example talks about a potentiometer, the process works for any resistive sensor.)

Lecture: Drones
  1. Drones!!
  2. Online Quiz: Review analog output transducers and controlling power.
    Do quiz on MyLearningSpace between 7 a.m. Friday and 11:30 p.m. Sunday evening.




 
  • Lab A: Raspberry Pi Stepper Motors  [ October 30, 2018 ]

    Note: If you finish early, start on Lab B.

  • Lab B: Controlling Power to a DC Motor   [ October 28, 2019 ]
  • No postlab requirements; you can start on the project.

  • After this week's labs, you know how to control stepper motors and servo motors with the Raspberry Pi and how to get analog voltages from the outside world into the Raspberry Pi.




TM1638 sample board [video]
tm1638 board
 

March 7
No lectures; project schedule
Deliverable (Lab A): One of four devices
Deliverable (Lab B): Two of four devices


 
  • Lab A: Demonstrate 1 input or output device
    Suggestion: Pick a motor, since you should have working code from recently. Then you can choose a distance sensor to start working on for Lab B.
    Echo signal from ultrasonic distance sensor must go through optoisolator!

  • Lab B: Demonstrate previous device and 1 other.
    Note: You can have different test programs for each device, but they must both be physically connected at the same time.
    Decide on 3rd device to use.

Component Inventory

Project components - SR04 Ultrasonic range finders

SR04 ultrasonic distance sensor signals

GP2Y0A21YK
 

March 14
No lectures; project schedule
Deliverable (Lab A): Three of four devices
Deliverable (Lab B): All four devices

 
  • Lab A: Demonstrate previous devices and 1 other.
    Note: You can have different test programs for each device, but they must all be physically connected at the same time.
    Decide on 4th device to use.

    Remember one output can be a "monitoring voltage" or an LED of varying brightness.

  • Lab B: Demonstrate all input and output devices
    Note: You can have different test programs for each device, but they must all be physically connected at the same time.
 

March 21
No lectures; project schedule
Deliverable (Lab B): Integration Project demonstration and report
Integration Project checklist [PDF]   [ January 3, 2019 ]
Block Diagrams   [ February 13, 2019 ]
Block Diagram Elements [HTML]   [ November 9, 2017 ]
Block Template
Signals for block diagrams library for Dia
(Use this if you are installing Dia on your own computer.)

draw.io online drawing app
Sample signals



 
  • Lab A: project work (Remember to include some form of operator interaction.)
  • Lab B: Demonstrate Integration project
 

March 28
On-line Course Evaluation March ?? until April ??
Deliverable (Lab A): Some functionality of exploration device

The goal is to do something that wasn't in an existing example, so that your report adds to the knowledge base for people after you.
Deliverable (Lab B): Demonstrate Exploration project

Documentation and final video due April ??
Exploration Project checklist [PDF]   [ October 23, 2019 ]



 
On-line Course Evaluation March ?? until April ??
  • Lab A: demonstrate basic functionality (i.e. doing something)
  • Lab B: Demonstrate Exploration project
 

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