Spring 2020 ICS2O-E: DER PROJECTS

There are no quizzes, tests, or exams in our ACES program. Put another way, you are NEVER put into the position of having a dramatically limited amount of time to demonstrate the skills you have acquired. You can invest as much (or as little) time into your reports as you choose. In return for being granted complete control over the depth and quality of your submissions I can place a premium on detail, precision, and the pursuit of perfection. So, my advice to you if you want to become exceptional is to follow the written and oral instructions carefully and, beyond the required elements of each report, demonstrate tasteful and appropriate creativity and imagination to distinguish yourself from the mediocre. Good luck and, remember, the race is long but it's over quickly.

Reports. Required Elements

If you do not submit your report by the deadline specified, you receive a mark of 0. This is done as a favour to you to help you appreciate that the real world will dismiss you if you can not demonstrate responsibility and accountability. You are to archive ALL of your reports in the single Word document, DER.docx. The first page is your Title page, followed by a multi-page Table of Contents, after which your reports begin. EACH report will start at the top of the next new page and, unless otherwise specified, consist of the following sections, in the order listed,

Purpose

Reference

Procedure

Media

Reflection

The vast majority of us can tell the difference between quality and rubbish in an instant. As a young scholar you have to decide what your name will stand for. It should matter very little whether you enjoy a task or not; if you're going to attach your name to something it is a direct reflection of who you are.

Project 1.4. A Counting Circuit

This final activity provides a simple introduction to fundamental capabilities of many digital devices: counting and display. There are a number of stages or subcircuits in this system and your DER will clearly present the role played by each.

Start your DER with a big picture Theory section, written in your own words that mentions, generally, the input to the system, the generation of a clock signal consisting of pulses having both a duration and a frequency, culminating in the presentation of the pulse count on the display device. This would an ideal place to present a detailed, margin-to-margin Fritzing diagram, breadboard or (organized) schematic view, to introduce your readers to the full prototype you are about to describe and discuss in three pages that follow.

A Note on Graphics. Graphics should support the text they are illuminating. Poorly composed photos, sloppy and inconsistent choices for diagrams like pinouts and schematics work against you as they can confuse your readers and leave them with a sense that the author doesn't care about his presentation so why should they?

Follow the Theory Section with the eight subsections (A-H) described below. For the first section, Analog Input, include, as a graphic, that part of the schematic that it pertains to. The next five sections (B-F) subsections should include a Reference Section that includes the respective live hyperlink appearing below:

Following the Reference Subsection within each of the five areas, include a Purpose section (this one could go before the Reference Section) describing in detail, how each stage contributes to the sequence. Be sure to clearly present the input, processing, and output of each stage, supported by informative, attractive, and well-formatted graphics.

Following the final subsections include Media (captioned photos and video) and Reflection sections.

A. Analog Input

B. NAND Gate Oscillator (4011)

C. Decade Counter (4017)

D. Decimal Counting Binary Up/Down Counter (4510)

E. Binary Counting Decimal Decoder (4511)

F. Seven-Segment Display

G. A Counting Circuit PCB

Once the prototype media has been obtained for your DER (photos and video), ACES wishing to extend their engineering skills are encouraged to convert their breadboard prototype to a more permanent device. A custom printed circuit board was designed and manufactured expressly for the use by Jr. ACES for this purpose. Interested ACES should present their working prototype to Mr. D'Arcy at least TWO days prior to the DER due date in order to receive their PCB. Receipt of such a board comes with the expectation that components will be soldered, the circuit tested, and summarized in text, photos, and video as part of the DER summary for this Counting Circuit project.

H. A Counting Circuit PCB Case

Congratulations on reaching the final stage (8) of our marathon Counting Circuit project! Students that have successfully soldered their PCBs that demonstrate forward (and backwards) counting on the seven-segment display are invited to present their circuit to Mr. D. to receive a custom case designed and printed in the DES by J. Dolgin (ACES '20) into which their device can be mounted. A similar two-colour case was printed on the Ultimaker 3 in 2018 by K. Fiset-Algarvio (ACES '19). Click the image below to view a short time-lapse video of the case being printed,

Power for the device is sourced from a 9V battery inside a compartment within the interior of the case. The leads of a battery snap can be soldered to the correct pads in lieu of an external DC Jack. Be sure to place electrical tape across the battery to insulate it from the bottom of your PCB to prevent the possibility of shorting. Finally, screw the assembly together and fully test, prior to capturing the final frames of your project video.

Finally, be sure to address ALL issues from previous submissions and update your Table of Contents before attaching DER.docx to an email to handin under the Subject Line: A Counting Circuit (Complete)

Project 1.3. The Two-Bit Adder

With our recent look at the SR Latch (a memory element) you turned your knowledge of logic gates into the first of many useful digital circuits. In this first formal digital prototype you explore a second application: Addition. Consider the crazy notion of a digital circuit that could add 74 and 7. OK, let's think.

First of all, we need to appreciate that the two OPERANDS would be pulled from two memory locations within the computer (or calculator) in their binary form (computers, after all, know nothing about decimal) and our available OPERATORS are the digital logic gates we have studied (AND, OR, XOR, etc.). Now, performing addition in the way humans have been taught, the summing is undertaken from right to left. In our example, the rightmost bit pair (0 and 1) sum to 1. We could interpret this as, "for the inputs 0 and 1 we require an output of 1". Of the 16 possible two-input truth tables, many gates could produce a 1 for input of 0 and 1, so we should look at the other three possibilities for the two-input combination and examine their respective outputs before we commit to a specific logic gate. We'll do this in our Friday Meet.

Note that for the rightmost digit pair of inputs to the addition (in the green rectangle) there is no carry-in from a previous addition. The circuit we develop for this is called a Half-Adder and you'll find it's description on p. 58 of your workbook.

However, for the remaining seven operand pairs (in the red rectangle) any circuitry we develop MUST be prepared to accept a carry-in from a previous addition. Circuits for this type of addition, accepting a carry-in, is called a Full-Adder and you'll find it's description on p. 59 of your workbook.

Falstad Circuit Simulator

Although many of you likely could, Grade 10 students are not expected to have come up with the circuits designs for the half- and full-adder circuits, but a good grasp of why the work and the correct outcomes they produce provide deep mental satisfaction. To this end you are encouraged to spend time interacting with the relevant combinational samples provided on the Falstad site,

  1. Half-Adder: http://tinyurl.com/yyzawwaa
  2. Full-Adder: http://tinyurl.com/yxp7hseq
  3. Finally, Jr. ACES considering pursuing our Grade 11 course next year are encouraged to develop a Falstad Two-Bit Adder circuit, by starting with a Blank Circuit and combining the half and full adders into a single circuit. If you do, be sure to include a link and image in your DER and include it in your 2:00 minute video as well.

Task.

  1. After sufficiently researching the half- and full-adder circuits, you are to wire up a prototype on a breadboard that demonstrates a two-bit adder. This would demonstrate the limited sum of two operands, each from 0 to 3, for a sum over the range from 0 to 6.
  2. Parts will include 4 push buttons (or slide switches) for inputs A and B inputs, three LEDs for outputs, and the required CMOS ICs as the processor that integrates the half- and full adders..
  3. DER. Again, USING THE DER I SENT BACK TO YOU, and taking into account the personal and general Feedback comments you have been provided with, start this report on first new page, after the The Astable Multivibrator Report. Add the Project name in Heading 1 Style and complete sections under the subheadings: Purpose, Reference, Theory, Procedure, Media, and Reflection. Text is developed in accordance with the recommendations for Technical Writing and reflective of your much-improved formatting abilities. Graphic manipulation is undertaken according to the specifications laid out in the Engineering Report General Guidelines.
  4. There are many ways to demonstrate both your knowledge and your passion for this material. Utilities such as Fritzing, TinkerCAD Circuits, Falstad, etc. all offer ways to enhance you reader's experience. You do not need to include all of them as creating a strong report is NOT about checking all the boxes possible. Pick one or two you are drawn to and exploit their capabilities to teach the reader about how digital logic gates can be combined to perform the addition of a pair of two-bit binary operands.
  5. Attach your DER to an email to handin with the Subject: The Two-Bit Adder by Saturday May 9 at midnight.
  6. Finally, get started EARLY so you can seek additional clarification at either (or both) of our two Meets this week. Also, feel free to post questions to our ICS2OForum.

Project 1.2. The Astable Multivibrator (aka, The Analog Oscillator)

The Square Wave, a highly orchestrated sequence of alternating high and low durations, is the backbone of modern, digital, communication. The purpose of this project is to introduce you to the transistor and to demonstrate how it can be combined with other familiar analog components to produce an oscillating signal with properties similar to the digital square wave.

Task.

  1. Clean the lens of your phone's camera, as you will be gathering media (photos and videos) throughout this project, from start to finish, in support of your DER project summary due Saturday April 11.
  2. This project will test your organizational abilities as much as your nascent electronics' knowledge and skills. Part of the task includes thinking deeply about what you're doing.
  3. Examine the schematic of the Astable Multivibrator circuit (below, left) (aka, Analog Oscillator, Blinker). What becomes readily apparent is the pair of cross-coupled Resistor-Capacitor (RC) subcircuits. From previous lessons, you recognize RC pairs as indicative of a form of timing mechanism within circuitry.
  4. After you familiarize and locate the necessary components, prototype the circuit on your breadboard. This is the most complex circuit to date and it will require all of your best practices for assembly and schematic interpretation skills.
  5. When you are confident the circuit has a chance of functioning, apply your 9V power supply. Debug as necessary and document the results with your phone's camera. You may wish to experiment with the rate at which the LEDs are flashing by adjusting the sizes of the resistors and capacitors. Be sure to summarize these trials within a neat table in your DER.
    Schematic PCB: Dry Fit (Postponed)

  6. You may wish to research and explore variations on this common circuit as in flashing more or different coloured LEDs, or even a buzzer or speaker to create an audio siren or alert ( I can suggest this now because we're not together in the DES :)
  7. DER. Starting on a new page, add the Project name and complete sections under the subheading: Purpose, Reference, Theory, Procedure, Media, and Reflection. Text is developed in accordance with the recommendations for Technical Writing and reflective of your much-improved formatting abilities. Graphic manipulation is undertaken according to the specifications laid out in the Engineering Report General Guidelines.
  8. Attach your DER to an email to handin with the Subject: The Astable Multivibrator (aka The Analog Oscillator ) by the deadline.

Project 1.2. The Capacitor Visualizer

Along with resistors, capacitors belong to a family of components known as passives in that they do not introduce a new source of energy into a circuit. Capacitors serve a number of useful functions in both DC and AC circuits. In completing this project you will strengthen your understanding that the capacitor (in series with a resistor), plays in the timing aspects of analog DC circuitry.

This project takes time to undertake properly, so be patient, and start early.

The schematic, below left, is of a straightforward test circuit that, in my view, best illustrates of the functional behaviour of an electrolytic capacitor in a DC circuit. You are familiar with the concept of a voltage divider from your first project. Looking at the junction (node) between S1, R1 and R2, we introduce the notion of a current divider as the current splits into two branches due to their parallel configuration.

We have discussed the charging of an empty capacitor and the effect this has on the capacitor in terms of its resistance (in AC circuits this property is referred to as reactance). In a DC circuit, a single RC Time Constant, denoted τ, can be expressed simply as,

`τ=R×C`

where τ is measured in seconds, R is measured in Ω, and C is measured in F. Also discussed in class (p. 33) is the expectation that after 5 RC time constants the capacitor is virtually fully charged (5τ~99%). One of the objectives of this project is to observe and confirm the expected results.

Schematic Printed Circuit Board

Task.

  1. To achieve the best results for each of the numerous trials, the capacitor should be fully drained. In the Procedure section of your report, explain how this is achieved in the circuit to the right.
  2. On a breadboard, prototype the circuit above left as neatly as you can using the first pair of resistor-capacitor values in the table below. Connect the longer lead of the bicolor LED to the capacitor and the shorter lead to ground. This ensures the orientation that agrees with the schematic. Note: Be sure to drain the capacitor and measure the voltage with your DMM to be sure. Explain this step in your Procedure and explain any related issues you have in achieving this.
  3. Once connected, hold the momentary button down (for as is required) before releasing it. Note the behaviour of the LEDs in particular, and try to explain what electrical behaviour at work, throughout. Do this a number of times until you feel you understand the principles.
  4. Now, more formally, using the timer on your phone, and through observation, record the approximate charging time for a fully discharged state until your eyes can no longer detect a visible state change in the red LED. A DMM can be used for more accurate results. Perform at least three trials with the first Resistor-Capacitor pair and record the average.
  5. For your DER, you are asked to duplicate the table that appears below. In the third column determine and enter the theoretical (expected) time to fill. In the fourth column, enter your observed result.


  6. Repeat Steps 3 and 4 for each of the remaining 2 RC pairs in the table. Again, perform a number of trials with each pair and record the average.
  7. For your DER summary of this Project, you MUST remember to obtain media of your prototype (both still images and video), before you dismantle it to solder together your completed device on the PCB provided. Be sure to watch the Instructional video, prior to soldering. Finally, demonstrate a WORKING version of your soldered PCB to me by Thursday October 31 to obtain a custom case for your device.
  8. In your DER, be sure to include the required sections listed above. You are to provide your own Fritzing schematic It is up to you to decide the supporting images and graphics that engage your readers and leave them with a solid understanding of the concepts. The table above is large enough to be center-aligned on your page.
  9. Attach your (corrected) DER to an email to handin under the Subject Line: The Capacitor Visualizer by the deadline.

Project 1.1. Photodetection

One of the most important skills an Engineer must possess is the ability to communicate, both in spoken word and in written form, in a highly structured format. Developing this skill takes much practice and this is precisely why the Design Engineering Report plays such a crucial role in our program, your mark, and your future.

With the skills gained over the past few classes, you are ready to prepare your first Design Engineering Report (DER) submission. Furthermore, you are required to be familiar with the Guide for Technical Writing and, through practice and regular editing, your sentence structure will improve. Poor grammar and spelling skills detract from your presentation.

The Photodetection circuit provides a vivid reflection of the fundamental voltage, current and resistance concepts we have explored and analyzed over the first dozen classes. A schematic of the circuit appears to the right. Roll your mouse over the image to reveal a letter H formed by two voltage dividers (one variable and the other, fixed) spanned by a bicolor LED.

Given the amount of time you have to prototype, study, and analyze this circuit, clearly the value eventually awarded you rests not with the mere presentation of a working circuit, but in the depth and creativity of your explanation and presentation that employs the tools that you have at your disposal. One area of creativity you should consider is the manner in which you introduce extreme swings of light and dark input to your prototype.

Task.

  1. Create the Word document, DER.docx that includes a Title page, Table of Contents and headers and footers as discussed and developed in class.
  2. Each Project writeup in your ACES career starts on a new page.
  3. For this project, start a new page, be sure the page numbering starts at page (Arabic) 1, and place Project 1.1 Photodetection in Heading 1 Style at the top of the page. Subsections, styled as Heading 2, must include,
    1. Purpose one or two short, well-constructed sentences that underscore the precise concept(s) being highlighted in his project
    2. Reference include a hyperlink pointing to the URL of this project description and any other online resource(s) you explored with advantage
    3. Procedure discuss the concept of a voltage divider in general, how two are employed in this circuit, what purpose they each serve, and how the entire circuit works. The highest credit will be reserved for those authors whose discussion provides clear explanations of how Ohm's Law and Kirchhoff's Laws influence the signals (this will take time, so start early). Include a complete, 3" wide, alternate background-shaded, Parts Table, and YOUR unique duplication of the schematic above right, created in Fritzing, 3" wide and right-aligned.
    4. Media formatted and captioned photos and (no more than) 2-minute video uploaded from your personal YouTube channel. By personal, I mean you do NOT use your RSGC email or other credentials to create this channel as your material will disappear after graduation. You can't afford to lose this work.
    5. Reflection this is the only segment written in the first person and includes any comments you have about the concepts, the build process, any challenges you overcame and personal time-management issues you were pleased with or need to address in the future.
  4. Technical writing is done on the present, active voice, NOT presented in the first, second or third person. See these do and don't examples.
  5. Develop your own Fritzing breadboard and schematic images for inclusion in your submission and store them in your images folder. Include them in the Media subsection together with high resolution, well-composed, and formatted photos.
  6. The 2-minute landscape-oriented video of your circuit includes accompanying explanations and annotations of the components. Upload to YouTube within your own personal channel (not RSGC's) and include a full URL link in the Media section. Some of our best videos appear on our ACES' home page carousel.
  7. Update your Table of Contents.
  8. Attach your Design Engineering Report (DER.docx) to an email to handin with the Subject: Photodetection by the required deadline.

Remember, your text should be developed in accordance with the recommendations for Technical Writing.