Design Document Check

updated Fa 2020

Description

The Design Document Check (DDC) is intended to aid your team as it prepares its Design Document. The DDC focuses narrowly upon providing feedback on the preparation of historically problematic Design Document elements. If these elements fall short during your Design Review the following week, precious time is lost.

What are the course staff looking for? i) Evidence that the overall idea of the design is sound; ii) A check of a small subset of required components indicates that the project is on the right track.

Below is a checklist of things to have ready for the design document check. Refer to the design document page and grading rubric for a full description of each item.
  1. Introduction
    1. Start with a brief summary (30 sec) or elevator pitch following this template:

      I will build ___A___ (my core product) for ___B___ (my core customer: the person who pays my company or uses the product).

      My customer has a problem ___C___ (describe the problem your customer has)

      My product solves my customer’s problem by ___D___ (how do you solve the problem?)

    2. Be expected to explain further what the problem is, what’s your idea to solve it, and why your idea is novel.
  2. Visual Aid
  3. High-level Requirements
    1. HL requirements are derived from the problem you are trying to solve (put yourself into the customer's shoes). HL requirements should be the essential features that your customers/users really care about. These features distinguish your product from others (e.g. ones available in the market or previous 445 designs). Be abstract (no tech details, you may come up with different design due to other constraints but still solve this problem), quantifiable (no words like continuously, accurately, etc), and unambiguous. HL&RV slides(P.5) has a good example.
    2. We will look at your HL requirements and check if they are what your customers/users really care about. Be prepared to defend your requirements, so that when you get challenged, you can give a well thought out explanation.
  4. Block Diagram
    1. Block Diagram slides
    2. We will check whether this design appears to solve your problem. 
    3. We will check if formatting is clear (lines, legends, etc). Extra caution is needed as students often make mistakes here (but you shouldn't!).
  5. Requirements & Verification Tables
    1. HL&RV slides: from P. 1-17
    2. Block Module Requirements: Break down your HL requirements into block level requirements. These are the requirements in the RV table (they are not the specs of the parts you have chosen).
    3. Verification: A step-by-step approach allows another 445 student to test if the BL requirement is satisfied. This is like an instruction for your module's unit test (with some surrounding dummy modules, a.k.a, mock object(s)
    4. We will review one piece of it. Show us an important one.
  6. Plots
  7. Circuit Schematics
  8. Tolerance Analysis
    1. Identify an important part that you need to perform some quantitative analysis on. This part should have quantitative values critical to the design and require you do calculations and make trade-offs in order to achieve your best design.
    2. Common mistake: Many students do calculations for tangential parts to pad the space.
  9. Safety & Ethics
  10. Citations

During the DDC, your team will have 5-8 minutes to present an example of each of these elements. Expect to share the 30-minute DDC session with two other design teams. Come prepared to learn from their work - both the good and bad.

Your task is to prepare and upload the above elements in a single PDF document to the course website. During your DDC session, you will present directly from your submission, which will be projected for all to see.

The focus of the DDC is not on the details of your design but rather on the details of your formatting; the design of your project will be covered in-depth during the Design Review. Organize your submission in accordance with the Design Document guidance and the example Design Document.

The course staff will focus on providing feedback on the format of your sample DDC elements - the very limited available time will not afford detailed feedback on your design. Please go to office hours for further guidance.

Requirements and Grading

Upload your DDC submission to your project page on PACE (i.e. ECE 445 web board) before arriving at your DDC session.

As in your Design Document, number pages after the title page in your DDC submission.

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.

The course staff at the DDC will assign individual grades to each student based on:

Submission and Deadlines

Sign-up for the Design Document Check on the ECE 445 course website - specifically at the Sign up for Team Presentation item on the PACE tab. Sign-up will open the Monday one week prior to the DDCs.

Upload your DDC submission (.pdf format) to the ECE 445 course website before your DDC session - specifically at the My Project item on the PACE tab.

While you will not complete peer reviews during the DDC, you are expected to actively contribute to the discussion.

Tech must-know and FAQ for design

Here is the link of "Tech must-know and FAQ for design" which is accessible after logging into g.illinois.edu.

Over semesters, ECE445 course staff have encountered repeated mistakes from students. The document above is designed to provide students with the essential knowledge needed in order to have a good design. Spending 5 min reading it might save you 15 hours later. Also, there might be some quiz questions in your DDC or Design Review. Please help us improve this document. We value your feedback!

Instant Nitro Cold Brew Machine

Danis Heto, Mihir Vardhan

Instant Nitro Cold Brew Machine

Featured Project

# Instant Nitro Cold Brew Machine

Team Members:

- Mihir Vardhan (mihirv2)

- Danis Heto (dheto3)

# Problem

Cold brew is made by steeping coffee grounds in cold water for 12-18 hours. This low-temperature steeping extracts fewer bitter compounds than traditional hot brewing, leading to a more balanced and sweeter flavor. While cold brew can be prepared in big batches ahead of time and stored for consumption throughout the week, this would make it impossible for someone to choose the specific coffee beans they desire for that very morning. The proposed machine will be able to brew coffee in cold water in minutes by leveraging air pressure. The machine will also bring the fine-tuning and control of brewing parameters currently seen in hot brewing to cold brewing.

# Solution

The brew will take place in an airtight aluminum chamber with a removable lid. The user can drop a tea-bag like pouch of coffee grounds into the chamber along with cold water. By pulling a vacuum in this chamber, the boiling point of water will reach room temperature and allow the coffee extraction to happen at the same rate as hot brewing, but at room temperature. Next, instead of bringing the chamber pressure back to atmospheric with ambient air, nitrogen can be introduced from an attached tank, allowing the gas to dissolve in the coffee rapidly. The introduction of nitrogen will prevent the coffee from oxidizing, and allow it to remain fresh indefinitely. When the user is ready to dispense, the nitrogen pressure will be raised to 30 PSI and the instant nitro cold brew can now be poured from a spout at the bottom of the chamber.

The coffee bag prevents the coffee grounds from making it into the drink and allows the user to remove and replace it with a bag full of different grounds for the next round of brewing, just like a Keurig for hot coffee.

To keep this project feasible and achievable in one semester, the nitrogenation process is a reach goal that we will only implement if time allows. Since the vacuum and nitrogenation phases are independent, they can both take place through the same port in the brewing chamber. The only hardware change would be an extra solenoid control MOSFET on the PCB.

We have spoken to Gregg in the machine shop and he believes this vacuum chamber design is feasible.

# Solution Components

## Brewing Chamber

A roughly 160mm tall and 170mm wide aluminum chamber with 7mm thick walls. This chamber will contain the brew water and coffee grounds and will reach the user-set vacuum level and nitrogenation pressure if time allows. There will be a manually operated ball valve spout at the bottom of this chamber to dispense the cold brew once it is ready. The fittings for the vacuum hose and pressure sensor will be attached to the screw top lid of this chamber, allowing the chamber to be removed to add the water and coffee grounds. This also allows the chamber to be cleaned thoroughly.

## Temperature and Pressure Sensors

A pressure sensor will be threaded into the lid of the brewing chamber. Monitoring the readings from this pressure sensor will allow us to turn off the vacuum pump once the chamber reaches the user-set vacuum level. A temperature thermocouple will be attached to the side of the brewing chamber. The temperature measured will be displayed on the LCD display. This thermocouple will be attached using removable JST connectors so that the chamber can be removed entirely from the machine for cleaning.

## Vacuum Pump and Solenoid Valve

An oilless vacuum pump will be used to pull the vacuum in the brewing chamber. A solenoid valve will close off the connection to this vacuum pump once the user-set vacuum pressure is reached and the pump is turned off. To stay within the $100 budget for this project, we have been given a 2-Stage 50L/m Oil Free Lab Vacuum Pump on loan for this semester. The pump will connect to the chamber through standard PTFE tubing and push-fit connectors

If time allows and we are able to borrow a nitrogen tank, an additional solenoid and a PTFE Y-connector would allow the nitrogen tank to connect to the vacuum chamber through the same port as the vacuum pump.

## LCD Display and Rotary Encoder

The LCD display allows the user to interact with the temperature and pressure components of the brewing chamber. This display will be controlled using a rotary encoder with a push button. The menu style interface will allow you to control the vacuum level and brew time in the chamber, along with the nitrogenation pressure if time allows. The display will also monitor the temperature of the chamber and display it along with the time remaining and the current vacuum level.

# Criterion For Success

- A successful cold brew machine would be able to make cold brew coffee at or below room temperature in ten minutes at most.

- The machine must also allow the user to manually control the brew time and vacuum level as well as display the brew temperature.

- The machine must detect and report faults. If it is unable to reach the desired vacuum pressure or is inexplicably losing pressure, the machine must enter a safe ‘stop state’ and display a human readable error code.

- The reach goal for this project, not a criterion for success, would be the successful nitrogenation of the cold brew.

Project Videos