Design Document

Description

The design document communicates the complete and detailed design of your project. It is substantially more detailed than the proposal and prepares you for the assembly phase of the semester. A quality design document is the key to a successful project (sample document). Use the following format:

  1. Introduction

    • Problem and Solution:

      One to two paragraphs explaining the context of the problem to be solved by your project, including any relevant references to justify the existence and/or importance of the problem (i.e., the need or want for a solution). Justify the novelty of your solution or explain the expected improvements of your solution over previous results.

    • Visual Aid

      A pictorial representation of your project that puts your solution in context. Not necessarily restricted to your design. Include other external systems relevant to your project (e.g. if your solution connects to a phone via Bluetooth, draw a dotted line between your device and the phone). Note that this is not a block diagram and should explain how the solution is used, not a breakdown of inner components.

    • High-level requirements list:

      A list of three to four objective characteristics that this project must exhibit in order to solve the problem. These should be selected such that if any of these requirements were not met, the project would fail to solve the problem. Avoid vague requirements that can be interpreted a number of ways (e.g. "The radio subsystem should work reliably."). Each high-level requirement must be stated in complete sentences and displayed as a bulleted list.

  2. Design

    • Block Diagram:

      A general block diagram of the design of your solution. Each block should be as modular as possible and represent a subsystem of your design. In other words, they can be implemented independently and re-assembled later. The block diagram should be accompanied by a brief (1 paragraph) description of the critical subsystems and what they do.

    • Physical Design (if applicable):

      A physical diagram of the project indicating things such as mechanical dimensions or placement of sensors and actuators. The physical diagram should also be accompanied by a brief one paragraph description.

    • [Subsystem X]

      For each subsystem in your block diagram, you should include a highly detailed and quantitative block description. Each description must include a statement indicating how the block contributes to the overall design dictated by the high-level requirements. Any and all design decisions must be clearly justified. Any interfaces with other blocks must be defined clearly and quantitatively.

      Include any relevant supporting figures and data in order to clearly illustrate and justify the design. Typically a well justified block design will include some or all of the following items: Circuit schematics, simulations, calculations, measurements, flow charts, mechanical diagrams (e.g. CAD drawings, only necessary for mechanical components).

      You must include a Requirements and Verifications table. Please see the R&V page for guidance on writing requirements and verification procedures.

    • [Subsystem Y]

      ...

    • [Subsystem Z]

      ...

    • Tolerance Analysis: Through discussions with your TA, identify the block or interface critical to the success of your project that poses the most challenging requirement. Analyze it mathematically and show that it can be feasibly implemented and meet its requirements. See the Tolerance Analysis guide for further guidance.
  3. Cost and Schedule

    1. Cost Analysis: Include a cost analysis of the project by following the outline below. Include a list of any non-standard parts, lab equipment, shop services, etc., which will be needed with an estimated cost for each.
      • Labor: (For each partner in the project)
        Assume a reasonable salary
        ($/hour) x 2.5 x hours to complete = TOTAL
        Then total labor for all partners. It's a good idea to do some research into what a graduate from ECE at Illinois might typically make.
      • Parts: Include a table listing all parts (description, manufacturer, part #, quantity and cost) and quoted machine shop labor hours that will be needed to complete the project.
      • Sum of costs into a grand total
    2. Schedule:

      Include a time-table showing when each step in the expected sequence of design and construction work will be completed (general, by week), and how the tasks will be shared between the team members. (i.e. Select architecture, Design this, Design that, Buy parts, Assemble this, Assemble that, Prepare mock-up, Integrate prototype, Refine prototype, Test integrated system).

  4. Discussion of Ethics and Safety:

    1. Expand upon the ethical and safety issues raised in your proposal to ensure they are comprehensive. Add any ethical and safety concerns that arose since your proposal.
    2. Document procedures to mitigate the safety concerns of your project. For example, include a lab safety document for batteries, human/animal interfaces, aerial devices, high-power, chemicals, etc. Justify that your design decisions sufficiently protect both users and developers from unsafe conditions caused by your project.
      Projects dealing with flying vehicles, high voltage, or other high risk factors, will be required to produce a Safety Manual and demonstrate compliance with the safety manual at the time of demo.
  5. Citations:

    Any material obtained from websites, books, journal articles, or other sources not originally generated by the project team must be appropriately attributed with properly cited sources in a standardized style such as IEEE, ACM, APA, or MLA.

Submission and Deadlines

Your design review document should be uploaded to PACE in PDF format by the deadline shown on the course calendar . If you have uploaded a mock DR document to PACE, please make sure that it has been removed before DR.

Habit-Forming Toothbrush Stand

John Kim, Quinn Palanca, Rahul Vasanth

Habit-Forming Toothbrush Stand

Featured Project

I spoke with a TA that approved this idea during office hours today, and they said I should submit it as a project proposal.

# Habit-Forming Toothbrush Stand

Team Members:

- Rahul Vasanth (rvasant2)

- Quinn Andrew Palanca (qpalanc2)

- John Jung-Yoon Kim (johnjk5)

# Problem

There are few habits as impactful as good dental hygiene. Brushing teeth in the morning and night can significantly improve health outcomes. Many struggle with forming and maintaining this habit. Parents might have a difficult time getting children to brush in the morning and before sleep while homeless shelter staff, rehab facility staff, and really, anyone looking to develop and track this habit may want a non-intrusive, privacy-preserving method to develop and maintain the practice of brushing their teeth in the morning. Keeping track of this information and but not storing it permanently through a mobile application is something that does not exist on the market. A small nudge is needed to keep kids, teenagers, and adults of all ages aware and mindful about their brushing habits. Additionally, many tend to zone out while brushing their teeth because they are half asleep and have no idea how long they are brushing.

# Solution

Our solution is catered toward electric toothbrushes. Unlike specific toothbrush brands that come with mobile applications, our solution applies to all electric toothbrushes, preserves privacy, and reduces screen time. We will implement a habit-forming toothbrush stand with a microcontroller, sensors, and a simple LED display that houses the electric toothbrush. A band of sensors will be wrapped around the base of the toothbrush. Lifting the toothbrush from the stand, turning it on, and starting to brush displays a timer that counts seconds up to ten minutes. This solves the problem of brushing too quickly or losing track of time and brushing for too long. Additionally, the display will provide a scorecard for brushing, with 14 values coming from (morning, night) x (6daysago, 5daysago, . . . , today) for a "record" of one week and 14 possible instances of brushing. This will augment the user's awareness of any new trends, and potentially help parents, their children, and other use cases outlined above. We specifically store just one week of data as the goal is habit formation and not permanent storage of potentially sensitive health information in the cloud.

# Solution Components

## Subsystem 1 - Sensor Band

The sensor band will contain a Bluetooth/Wireless Accelerometer and Gyroscope, or Accelerometer, IR sensor (to determine height lifted above sink), Bluetooth/Wireless connection to the microcontroller. This will allow us to determine if the electric toothbrush has been turned on. We will experiment with the overall angle, but knowing whether the toothbrush is parallel to the ground, or is lifted at a certain height above the sink will provide additional validation. These outputs need to be communicated wirelessly to the habit-forming toothbrush stand.

Possibilities: https://www.amazon.com/Accelerometer-Acceleration-Gyroscope-Electronic-Magnetometer/dp/B07GBRTB5K/ref=sr_1_12?keywords=wireless+accelerometer&qid=1643675559&sr=8-12 and individual sensors which we are exploring on Digikey and PCB Piezotronics as well.

## Subsystem 2 - Toothbrush Base/Stand and Display

The toothbrush stand will have a pressure sensor to determine when the toothbrush is lifted from the stand (alternatively, we may also add on an IR sensor), a microcontroller with Bluetooth capability, and a control unit to process sensor outputs as well as an LED display which will be set based on the current state. Additionally, the stand will need an internal clock to distinguish between morning and evening and mark states accordingly. The majority of sensors are powered by 3.3V - 5V. If we use a battery, we may include an additional button to power on the display (or just have it turn on when the pressure sensor / IR sensor output confirms the toothbrush has been lifted, or have the device plug into an outlet.

# Criterion For Success

1. When the user lifts the toothbrush from the stan and it begins to vibrate (signaling the toothbrush is on), the brushing timer begins and is displayed.

2. After at least two minutes have passed and the toothbrush is set back on the stand, the display correctly marks the current day and period (morning or evening).

3. Track record over current and previous days and the overall weekly record is accurately maintained. At the start of a new day, the record is shifted appropriately.

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