Purdue University Fort Wayne
Department of Electrical and Computer Engineering
Dr. David S. Cochran | Mr. Joseph Smith
An iterative design methodology that compresses time from concept to physical prototype through:
| Aspect | Traditional | Rapid Prototyping |
|---|---|---|
| Design cycles | Sequential, long | Parallel, compressed |
| First prototype | Months to years | Days to weeks |
| Iteration cost | High | Low |
| Learning | Late-stage | Continuous |
| Risk discovery | Production phase | Early development |
| Phase | AI Application |
|---|---|
| Ideation | Concept variations, patent search |
| Design | Generative design, code generation |
| Validation | Simulation setup, test generation |
| Documentation | Technical writing, drawing generation |
AI Can:
AI Cannot:
"The AI suggested it" is never an acceptable answer.
Students must be able to explain:
If you cannot explain your engineering decisions, you will not pass.
Problems: Late discovery, expensive changes, long time-to-market
Enablers: Generative design, code generation, digital twins, AI documentation
| Subsystem | Components | Challenges |
|---|---|---|
| Mechanical | Housing, display mount, airflow | Thermal, aesthetics |
| Electrical | MCU, sensors, display, WiFi | Power, signal integrity |
| Software | HVAC control, UI, cloud | Real-time, reliability |
| Integration | All interfaces | Thermal, electrical fit |
Deliverable: Form project teams, begin defining system concept
Next week: Agile/Lean prototyping methodologies
| Software Agile | Hardware Adaptation |
|---|---|
| Working software | Functional prototypes |
| Customer collaboration | User testing sessions |
| Responding to change | Modular architecture |
| Individuals and interactions | Cross-functional teams |
Risk-driven iteration:
| Level | Prototype Type | Purpose |
|---|---|---|
| 1 | Paper/Foam mockup | Form factor, ergonomics |
| 2 | Breadboard electronics | Circuit validation |
| 3 | 3D printed + dev board | Integrated function |
| 4 | Custom PCB + housing | Near-production |
| Priority | Item | Points |
|---|---|---|
| 1 | Temperature sensing and display | 5 |
| 2 | HVAC relay control | 8 |
| 3 | WiFi connectivity | 8 |
| 4 | Air quality sensing (CO2) | 5 |
| 5 | Mobile app integration | 13 |
| 6 | Voice assistant integration | 13 |
| 7 | Learning algorithm | 21 |
Next week: Concept-to-Prototype Workflows
AI tools can accelerate ideation:
| Criteria | Weight | Concept A | Concept B | Concept C |
|---|---|---|---|---|
| Cost | 3 | + | S | - |
| Performance | 5 | S | + | + |
| Complexity | 2 | - | S | + |
| Time to market | 4 | + | + | S |
S = Same as baseline, + = Better, - = Worse
| Must Have | Should Have | Could Have | Won't Have |
|---|---|---|---|
| Temperature control | CO2 monitoring | VOC monitoring | Smoke detection |
| WiFi connectivity | Mobile app | Voice control | Humidity control |
| Display | Learning algorithm | Energy reports | Multi-zone |
| Easy installation | Occupancy sensing | Weather integration |
Deliverable: Concept definition document
Next week: Hardware Prototyping with AI
Modern capabilities: Parametric modeling, cloud collaboration, generative design
AI-driven design exploration:
| Technology | Materials | Resolution | Strength | Cost |
|---|---|---|---|---|
| FDM | PLA, ABS, PETG | Medium | Good | Low |
| SLA | Resin | High | Medium | Medium |
| SLS | Nylon, PA | Medium | Excellent | High |
| MJF | Nylon, PA | High | Excellent | High |
| Service | Capabilities | Turnaround |
|---|---|---|
| Protolabs | CNC, 3D print, molding | 1-15 days |
| Xometry | Multi-process | 3-10 days |
| JLCPCB | 3D print, PCB | 3-7 days |
| Shapeways | 3D print | 5-10 days |
| Requirement | Specification | Rationale |
|---|---|---|
| Dimensions | 120 x 100 x 25 mm | Wall mounting standard |
| Display cutout | 50 x 35 mm | Selected display module |
| Sensor chamber | Isolated airflow | Accurate readings |
| Mounting | Standard electrical box | DIY installation |
| Material | ABS/ASA | Thermal stability |
Next week: Software Prototyping with AI
| Tool | Capabilities | Integration |
|---|---|---|
| GitHub Copilot | Autocomplete, suggestions | VS Code, JetBrains |
| Claude Code | Full implementations | CLI, IDE |
| Cursor | AI-first IDE | Standalone |
| CodeWhisperer | AWS integration | VS Code |
| Component | Responsibility | Dependencies |
|---|---|---|
| Sensor Manager | Read sensors, filter data | HAL |
| HVAC Controller | Control relay outputs | Sensor Manager |
| Display Manager | UI rendering | Control state |
| Network Manager | WiFi, cloud connectivity | All data |
| Schedule Manager | Time-based control | HVAC Controller |
AI can help generate, optimize, and tune control algorithms
Next week: Hardware/Software Co-Design
Simultaneous development of hardware and software with:
| Section | Contents |
|---|---|
| Overview | System context, interface summary |
| Physical | Mechanical interfaces, drawings |
| Electrical | Pinouts, signals, protocols |
| Software | Data formats, APIs, timing |
| Verification | Test requirements |
| Sensor | Interface | Pins | Protocol |
|---|---|---|---|
| SHT40 (Temp/Humidity) | I2C | SDA, SCL | I2C @ 400kHz |
| SCD40 (CO2) | I2C | SDA, SCL | I2C @ 100kHz |
| SGP40 (VOC) | I2C | SDA, SCL | I2C @ 400kHz |
| Component | Active | Sleep |
|---|---|---|
| ESP32 | 80mA | 10uA |
| Display | 50mA | 0 |
| Sensors | 15mA | <1mA |
| WiFi TX | 300mA | 0 |
| Total | 445mA | <1mA |
Next week: Digital Twin Fundamentals
A virtual representation of a physical system that:
Next week: Midterm Presentations
By midterm, teams should have:
| Type | Description | Application |
|---|---|---|
| Physics-based | First principles modeling | Thermal, structural |
| Data-driven | ML models from data | Behavior prediction |
| Hardware-in-Loop | Real HW + simulated env | Controller testing |
| Software-in-Loop | Software + simulated HW | Algorithm validation |
| Test | Simulation Approach | Pass Criteria |
|---|---|---|
| Temperature accuracy | Thermal model | ±0.5°C |
| Control response | Simulink | <15 min to setpoint |
| Power consumption | Electrical model | <500mA average |
| Air quality response | Mass transfer model | <5 min detection |
Next week: Physical Prototype Fabrication
Before physical fabrication:
| Service | Layers | Min Trace | Turnaround | Cost (10) |
|---|---|---|---|---|
| JLCPCB | 2 | 0.15mm | 3-5 days | $5 |
| PCBWay | 2 | 0.15mm | 3-7 days | $5 |
| OSH Park | 2 | 0.15mm | 12 days | $25 |
| Advanced | 2 | 0.1mm | 1-5 days | $50 |
| Parameter | Value | Rationale |
|---|---|---|
| Layer height | 0.2mm | Balance detail/speed |
| Infill | 20-40% | Structural requirement |
| Walls | 3 perimeters | Strength |
| Material | PETG or ABS | Thermal stability |
| Supports | Minimal | Design to avoid |
Next week: Iterative Refinement
Metrics: Cycle time, Learning rate, Convergence
| Issue | Potential Cause | Experiment |
|---|---|---|
| High temp reading | PCB heat | Add thermal isolation |
| Slow CO2 response | Chamber airflow | Modify vent design |
| WiFi disconnects | Antenna interference | Reposition antenna |
| Display flicker | Power supply | Add capacitors |
Next week: Integration Testing
| Approach | Description | Risk |
|---|---|---|
| Big bang | Integrate all at once | High |
| Bottom-up | Start with low-level | Medium |
| Top-down | Start with high-level | Medium |
| Sandwich | Both directions | Low |
Next week: Prototype Documentation
A TDP contains all technical information needed to:
| Element | Contents |
|---|---|
| Specifications | Requirements, performance specs |
| Drawings | CAD models, engineering drawings |
| Schematics | Electrical designs |
| Software | Source code, documentation |
| Test data | Test procedures, results |
AI can help:
Important: AI output must be reviewed for accuracy!
Next week: Prototype to Production Transition
Design to:
| Element | Prototype | Production (1000) |
|---|---|---|
| PCB | $5/unit | $1/unit |
| Components | $60/unit | $45/unit |
| Housing | $15/unit | $3/unit |
| Assembly | $50/unit | $10/unit |
| Total | $130/unit | $59/unit |
Key Learning Outcomes:
| Resource | Location | Purpose |
|---|---|---|
| Student Project Guide | project_guide/ | Weekly checklists and deliverable tracking |
| Weekly Handouts | handouts/ | Worksheet-style exercises for each week |
| Resource Guide | resources/ | Standards, suppliers, services |
| Software Tools Guide | software_reference/ | Tool setup and tutorials |
Start with: project_guide/00_project_overview.md
Contact Information
Dr. David S. Cochran - cochrand@pfw.edu
Mr. Joseph Smith - smitjj09@pfw.edu
Office Hours: Wednesdays 2:30-4:30 PM, ETCS 229B
SE 54200 AI System Engineering Rapid Prototyping
Purdue University Fort Wayne