Senior Design: A Hands-on Experience with The Engineering Process

1
Senior Design A Hands-on Experience with The
Engineering Process
Design I
Design II
Problem
Test Verification
Design Constraints
Hardware Implementation, Design Refinement,
packaging
Design
Test Specification
Test Verification
Prototyping
Simulation
Test Verification
This is an iterative process
2
The Engineering Process
a design methodology . . .

• Problem recognize that a problem exists, and
  develop a concise statement of the problem.
• Objectives study the parameters of the problem,
  and convert them into engineering language you
  are familiar with.
• Literature Survey assimilate existing knowledge
  about the problem, and search for similar data
  (related experiments, evaluations, etc.)

3
The Engineering Process
a design methodology continued . . .

• Analysis analyze the problem based on the
  knowledge gained from the literature survey,
  produce a set of design constraints, and generate
  test specifications to verify these design
  constraints.
• Synthesis manipulate the analysis to yield a
  family of solutions (typically through simulation
  and prototyping).
• Evaluation choose the best solution and verify
  it meets the design constraints.
• Presentation communicate the solution to your
  peers/management.

4
Design I Structure

• Lectures Meets once a week
• Thursdays for Design I lectures, some weeks
  Tuesdays for Entrepeneurship lectures
• Lectures on team building, planning, software
  design, design document
• Assignments
• Writing assignments for design document in
  conjunction with GE 3513 tech writing
• Website (see syllabus)
• Presentations mid-term, end-of-semester

Must demonstrate working prototype of project at
end of semester!!
5
Design I Structure (cont.)

• Grading Design Document, presentations, weekly
  deliverables, peer reviews, web site, advisor
  input, etc (see syllabus)
• Team members do not necessarily all get the same
  grade!
• Custom grading forms for each team/presentation
• Funding Donations and other funding
• Ryan Green will handle this, 200 per team
• Lab Space Room 311, shared by Senior Design I
  II
• Conference Room Simrall 206

6
Success in Design 1 is Up to You!

• Progress on technical goals is entirely up to the
  team
• Faculty advisor is not a task master only
  advises
• The team sets the weekly goals, measures weekly
  progress
• Many projects require you to explore new
  technologies on your own initiative
• Welcome to life-long learning!
• Take advantage of all possible resources

7
Design I Pitfalls

• Design I is the critical semester
• Design II difficulty depends on Design I success
• Pitfalls
• Poorly specified goals, constraints for project
• Much time spent in semester beginning on this!!!
• Poor implementation choices for key technical
  aspects
• Spend time on tradeoff analysis, survey of
  alternatives!
• Lack of weekly progress
• Schedule a weekly meeting with your faculty
  advisor NOW.
• Make REAL progress connect wires, write code!
• Malfunctioning teams (more on this later)

8
Design I Complaints

• Believe it or not, we do listen to you!
• Increased from 1 hour to 4 hours spread over two
  semesters
• Integrated Design I writing with Tech Writing
• Added lab/meeting space reserved for Senior
  Design
• Common complaints
• Too much work for too little credit
• Design takes time get used to it
• Work smarter to reduce effort by using faculty,
  expert resources
• Why do we have to do assignment X? Just let us
  do our design!
• Planning, documentation, oral communication all
  are a real part of design!!!

9
Planning Your Project

• Phase 1 System definition
• Specifications and Features
• Physical Interface
• Subsystem definition and investigation of
  alternatives for each subsystem
• Phase 2 Design/test of individual subsystems
• Requires prototyping of different subsystems,
  perhaps even prototyping of different
  alternatives. Do not be surprised when something
  that you assumed turns out not to be true,
  requiring you to backtrack!
• agreement between team members on how subsystems
  will interact
• Phase 3 Subsystem integration
• Connecting subsystems together and getting them
  to work correctly takes time!

10
Writing Assignments vs. Project Development

• The writing assignments LAG the project
  development
• Your project development should be well ahead of
  the writing assignments, as the due dates for the
  writing assignments are spread out without regard
  to project development.
• Having the project development ahead of the
  writing assignments make the writing assignments
  easier, since you have something to write about!
• Writing up the different alternatives for a
  subsystem will be easy since you have already had
  actual experience with the subsystems.

11
Pitfalls in Project Development

• Do not assume that a circuit you find via Google
  will work the way that it is documented.
• Until you build it yourself, you know nothing.
• Understand the circuit! Simulate in Pspice if
  that is an option!
• If it is an analog circuit, when you integrate it
  with other components (like a microprocessor), it
  may quit operating.
• Read the datasheet!!!!!!
• If the datasheet specs are unsuitable, then dont
  waste your time.
• Consider packaging if the part is only
  available a surface mount package, it will be
  harder to prototype with.
• If a design has a lot of components, consider
  using a PCB from the start since breadboard
  wiring will drive you crazy.
• Order spare parts so that if something breaks,
  you will have a backup.

12
Pitfalls in Project Development (cont)

• Be careful how you divide the labor
• The best way is to divide it by subsystem, with
  lots of communications between the team members
  on how the subsystems interact
• In a hardware subsystem that has a
  microcontroller, you cannot divide the software
  development and the external hardware development
  between multiple people
• Software is needed to drive the hardware, and the
  software creator needs an intimate understanding
  of the hardware.
• You can divide it by functionality which combines
  hardwaresoftware (Joe will handle the LCD code
  and LCD interfacing, Sally will handle the DAC
  code and DAC interfacing).
• Everybody must contribute technically. You cannot
  have somebody whose only job is the web page or
  documentation!

13
Assign. 1 Product Specification

• One page
• Contains Applications, Features, Specifications
• Applications how can this be used?
• Features what can it do?
• Specifications quantitative measures of what it
  can and cannot do, requirements for use
• Visually appealing, tells all in one page
• Contains one or more graphics of product itself
  and usage of product in typical scenarios
• Post this on your web site (use .pdf files)

14
Example Specifications

• Signal tolerances (gt 30 duty cycle clock at 1MHz
  /-1)
• Supply current range (.5 mA min to 100 mA max)
• Power efficiency (83 supply efficiency at rated
  load)
• Speed, Response time (interrupt service latency lt
  10 ?S)
• Conversion rate (12-bit conversion at
  500Ksamples/sec)
• Transmission distance (100 M with unobstructed
  view)
• Quantization error (,- 5mV)
• Frequency response (20 Hz to 20 KHz, /- 3 dB)
• Signal-to-noise ratio (50 dB min)
• Power requirements (7 to 12 V DC)
• Environmental (functions in range of -25 C to
  125 C)
• Limitations (requires Windows XP or later)
• Battery life (battery lasts for 20 hours of
  constant use)