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.

Bracelet Aid for deaf people/hard of hearing

Aarushi Biswas, Yash Gupta, Anit Kapoor

Bracelet Aid for deaf people/hard of hearing

Featured Project

# PROJECT TITLE: Bracelet Aid for deaf people/hard of hearing

# TEAM MEMBERS:

- Aarushi Biswas (abiswas7)

- Anit Kapoor (anityak3)

- Yash Gupta (yashg3)

# PROBLEM

We are constantly hearing sounds around us that notify us of events occurring, such as doorbells, fire alarms, phone calls, alarms, or vehicle horns. These sounds are not enough to catch the attention of a d/Deaf person and sometimes can be serious (emergency/fire alarms) and would require the instant attention of the person. In addition, there are several other small sounds produced by devices in our everyday lives such as washing machines, stoves, microwaves, ovens, etc. that cannot be identified by d/Deaf people unless they are observing these machines constantly.

Many people in the d/Deaf community combat some of these problems such as the doorbell by installing devices that will cause the light in a room to flicker. However, these devices are generally not installed in all rooms and will also obviously not be able to notify people if they are asleep. Another common solution is purchasing devices like smartwatches that can interact with their mobile phones to notify them of their surroundings, however, these smartwatches are usually expensive, do not fulfill all their needs, and require nightly charging cycles that diminish their usefulness in the face of the aforementioned issues.

# SOLUTION

A low-cost bracelet aid with the ability to convert sounds into haptic feedback in the form of vibrations will be able to give d/Deaf people the independence of recognizing notification sounds around them. The bracelet will recognize some of these sounds and create different vibration patterns to catch the attention of the wearer as well as inform them of the cause of the notification. Additionally, there will be a visual component to the bracelet in the form of an OLED display which will provide visual cues in the form of emojis. The bracelet will also have buttons for the purpose of stopping the vibration and showing the battery on the OLED.

For instance, when the doorbell rings, the bracelet will pick up the doorbell sound after filtering out any other unnecessary background noise. On recognizing the doorbell sound, the bracelet will vibrate with the pattern associated with the sound in question which might be something like alternating between strong vibrations and pauses. The OLED display will also additionally show a house emoji to denote that the house doorbell is ringing.

# SOLUTION COMPONENTS

Based on this solution we have identified that we need the following components:

- INMP441 (Microphone Component)

- Brushed ERM (Vibration Motor)

- Powerboost 1000 (Power subsystem)

- 1000 mAh LiPo battery x 2 (hot swappable)

- SSD1306 (OLED display)

## SUBSYSTEM 1 → SOUND DETECTION SUBSYSTEM

This subsystem will consist of a microphone and will be responsible for picking up sounds from the environment and conducting a real-time FFT on them. After this, we will filter out lower frequencies and use a frequency-matching algorithm to infer if a pre-programmed sound was picked up by the microphone. This inference will be outputted to the main control unit in real-time.

## SUBSYSTEM 2 → VIBRATION SUBSYSTEM

This subsystem will be responsible for vibrating the bracelet on the wearer’s wrist. Using the vibration motor mentioned above, we should have a frequency range of 30Hz~500Hz, which should allow for the generation of a variety of distinguishable patterns. This subsystem will be responsible for the generation of the patterns and control of the motor, as well as prompting the Display subsystem to visualize the type of notification detected.

## SUBSYSTEM 3 → DISPLAY SUBSYSTEM

The Display subsystem will act as a set of visual cues in addition to the vibrations, as well as a visual feedback system for user interactions. This system should not draw a lot of power as it will be active only when prompted by user interaction or by a recognized sound. Both of these scenarios are relatively uncommon over the course of a day, which means that the average power draw for our device should still remain low.

## SUBSYSTEM 4 → USER INTERACTION SUBSYSTEM

This subsystem is responsible for the interaction of the user with the bracelet. This subsystem will include a set of buttons for tasks such as checking the charge left on the battery or turning off a notification. Checking the charge will also display the charge on the OLED display thus interacting and controlling the display subsystem as well.

## SUBSYSTEM 5 → POWER SUBSYSTEM

This subsystem is responsible for powering the device. One of our success criteria is that we want long battery life and low downtime. In order to achieve this we will be using a power boost circuit in conjunction with two rechargeable 1000 mAh batteries. While one is charging the other can be used so the user doesn’t have to go without the device for more than a few seconds at a time. We are expecting our device to use anywhere from 20-50mA which would mean we get an effective use time of more than a day. The power boost circuit and LiPo battery’s JST connector allow the user to secure and quick battery swaps as well.

# CRITERION FOR SUCCESS

- The bracelet should accurately identify only the crucial sounds in the wearer’s environment with each type of sound having a fixed unique vibration + LED pattern associated with it

- The vibration patterns should be distinctly recognizable by the wearer

- Should be relatively low cost

- Should have prolonged battery life (so the power should focus on only the use case of converting sound to vibration)

- Should have a small profile and a sleek form factor

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