Project Brainstorming for Collaboration Device

flux

2:09

Chat History
Project
Layout

Deciding on document conversion.

Creating concise PDF-ready document.

Following tool priority policy.

Adjusting output formatting.

Using Knowledge Base Tool.

Including export instructions.

Below is a single-page, PDF-ready “Fabrication & Assembly Package” document for PCBWay. Paste this into a doc and export to PDF. All components are linked to your Flux project.
Project: Secure Classroom Handheld Student-Response Device
  1. Summary and build intent
  • Purpose: Handheld device for classroom polling and short voice clips. BLE onboarding, HTTPS REST to teacher dashboard, OTA A/B updates, enterprise Wi-Fi (EAP-TLS).
  • Use profile: 8 hours active per day.
  • Core modules:
    • MCU: U1 Wi-Fi + BLE with PDM/I2S mic input (no speaker).
    • Power: 1-cell Li-ion charger U2, 3.3 V buck U3, optional quiet LDO U4.
    • Security: I2C secure element U5.
    • Audio: Digital mic U6 via PDM/I2S.
    • I/O: Buttons SW1, SW2, SW3; RGB LED LED1; mic hard-mute switch SW4.
    • Connectors/Protection: USB-C J1, USB ESD array D1, reverse-polarity diode D2, VBUS TVS D3.
    • Programming: 6-pin header J2.
  1. PCB fabrication specifications
  • Layers/stackup: 4 layers (Standard 4 Layer in Flux).
  • Material: FR-4, Tg ≥ 135 C.
  • Thickness: 1.6 mm nominal.
  • Copper: 1 oz outer, 0.5–1 oz inner.
  • Finish: ENIG preferred (lead-free HASL acceptable).
  • Soldermask/Silkscreen: Green/White, both sides.
  • Tolerances/quality: IPC Class 2.
  • Vias: Through-hole; tent SMD-area vias if needed.
  • NPTH mounting holes: Hole1, Hole2, Hole3, Hole4.
  • Controlled impedance: Not required.
  • Antenna keep-out: Strict keep-out under/near U1 module antenna (no copper or tall parts in near field).
  1. Assembly specifications
  • Standards: IPC-A-610 Class 2, RoHS lead-free (SAC305).
  • Stencil: 0.12 mm laser-cut stainless; 1:1 apertures for 0402 passives. Reduce only if tombstoning observed.
  • Polarity/orientation:
    • Diodes: D1, D2, D3 mark cathode.
    • LED: LED1 orientation per footprint indicator.
    • Switches/Buttons: SW1, SW2, SW3, SW4 per silkscreen outlines.
    • Module: U1 castellations; keep antenna region unobstructed.
  • ESD handling: Treat U1, U5, U6 as ESD sensitive.
  • Cleaning: No-clean acceptable.
  • DNP option: U4 and its caps may be DNP if buck output noise is acceptable.
  1. Key BOM line items (for reference) | RefDes | Description | |---|---| | U1 | Wi-Fi+BLE MCU module (ESP32-class) with PDM/I2S | | U2 | Li-ion charger (USB-C input) | | U3 | 3.3 V buck regulator | | U4 | Optional low-noise 3.3 V LDO (DNP optional) | | U5 | I2C secure element | | U6 | PDM/I2S digital microphone | | J1 | USB-C receptacle | | D1 | USB data/CC ESD array | | D2 | Reverse-polarity protection diode | | D3 | TVS diode (VBUS surge/ESD) | | LED1 | RGB LED | | SW1, SW2, SW3 | Momentary buttons | | SW4 | Mic hard-mute switch | | R1, R2 | USB-C CC/VCONN resistors | | R3, R4 | I2C pull-ups | | C3–C9 | Decoupling/bulk capacitors | | J2 | 6-pin programming header | | GND | Ground reference |
  2. Critical DFM/DFA notes
  • Antenna keep-out for U1: no copper pours, traces, or tall parts within the module’s antenna near field.
  • Switching regulator locality: Keep U3 high-di/dt loop tight; manage local ground to prevent coupling into audio and RF; stitch locally to plane.
  • USB ESD path: Place D1 near J1; provide short, direct returns to GND.
  • Mic routing: Keep U6 away from switch node; route PDM clock/data short with continuous ground return.
  • Placement margin: Leave space for routing and vias and use airwires to visualize the routing paths.
  1. Test and programming (DFT)
  • Programming/debug: Access J2 for firmware flash and bring-up.
  • Basic power checks: Validate charger U2 from J1, 3.3 V rail from U3, optional LDO U4.
  • Functional checks:
    • Buttons SW1–SW3 respond; RGB LED1 drives.
    • Mic U6 capture recognized by MCU U1.
  • ESD/EMI: Verify no resets or latch-ups under ESD on USB and user I/O.
  1. Deliverables included (from us)
  • Fabrication: Gerbers (RS-274X), Excellon drill files, board outline, IPC-356 netlist (if requested).
  • Assembly: BOM (CSV), Pick-and-Place/Centroid (CSV), top/bottom assembly drawings (PDF), schematic PDF, this README.
  • Optional: Panel drawing if panelization requested.
  1. Panelization and labeling
  • Panelization: Not specified; fabricate as single boards unless instructed otherwise.
  • Labeling: Add assembly revision, date code, and device ID/QR on silkscreen if available.
  1. Acceptance criteria
  • Electrical: No shorts/opens; charger operates from 5 V USB-C; 3.3 V rails within ±5%.
  • Visual: Solder quality per IPC-A-610 Class 2; correct orientations for U1, U5, U6, D1, D2, D3, LED1.
  • Functional: Buttons/LED operate; MCU boots via J2; mic capture path functional.
If you want, I can add compact top/bottom assembly drawings with RefDes callouts and a one-line panel note. Do you want panelization now (units per panel, rail size, break-away style), or proceed as single boards?
Ask for panelization
Clarify antenna keep-out
Refine stencil guidance
Request assembly drawing help
Improve test strategy
117 days

Ready.

Sign up to send
  • Ground
    Ground
    A common return path for electric current. Commonly known as ground.
    jharwinbarrozo
    20.5M
  • Net Portal
    Net Portal
    Wirelessly connects nets on schematic. Used to organize schematics and separate functional blocks. To wirelessly connect net portals, give them same designator. #portal
    jharwinbarrozo
    43.0M
  • Power Net Portal
    Power Net Portal
    Wirelessly connects power nets on schematic. Identical to the net portal, but with a power symbol. Used to organize schematics and separate functional blocks. To wirelessly connect power net portals, give them the same designator. #portal #power
    jharwinbarrozo
    11.4M
  • Generic Resistor
    Generic Resistor
    A generic fixed resistor for rapid developing circuit topology. Save precious design time by seamlessly add more information to this part (value, footprint, etc.) as it becomes available. Standard resistor values: 1.0Ω 10Ω 100Ω 1.0kΩ 10kΩ 100kΩ 1.0MΩ 1.1Ω 11Ω 110Ω 1.1kΩ 11kΩ 110kΩ 1.1MΩ 1.2Ω 12Ω 120Ω 1.2kΩ 12kΩ 120kΩ 1.2MΩ 1.3Ω 13Ω 130Ω 1.3kΩ 13kΩ 130kΩ 1.3MΩ 1.5Ω 15Ω 150Ω 1.5kΩ 15kΩ 150kΩ 1.5MΩ 1.6Ω 16Ω 160Ω 1.6kΩ 16kΩ 160kΩ 1.6MΩ 1.8Ω 18Ω 180Ω 1.8KΩ 18kΩ 180kΩ 1.8MΩ 2.0Ω 20Ω 200Ω 2.0kΩ 20kΩ 200kΩ 2.0MΩ 2.2Ω 22Ω 220Ω 2.2kΩ 22kΩ 220kΩ 2.2MΩ 2.4Ω 24Ω 240Ω 2.4kΩ 24kΩ 240kΩ 2.4MΩ 2.7Ω 27Ω 270Ω 2.7kΩ 27kΩ 270kΩ 2.7MΩ 3.0Ω 30Ω 300Ω 3.0KΩ 30KΩ 300KΩ 3.0MΩ 3.3Ω 33Ω 330Ω 3.3kΩ 33kΩ 330kΩ 3.3MΩ 3.6Ω 36Ω 360Ω 3.6kΩ 36kΩ 360kΩ 3.6MΩ 3.9Ω 39Ω 390Ω 3.9kΩ 39kΩ 390kΩ 3.9MΩ 4.3Ω 43Ω 430Ω 4.3kΩ 43KΩ 430KΩ 4.3MΩ 4.7Ω 47Ω 470Ω 4.7kΩ 47kΩ 470kΩ 4.7MΩ 5.1Ω 51Ω 510Ω 5.1kΩ 51kΩ 510kΩ 5.1MΩ 5.6Ω 56Ω 560Ω 5.6kΩ 56kΩ 560kΩ 5.6MΩ 6.2Ω 62Ω 620Ω 6.2kΩ 62KΩ 620KΩ 6.2MΩ 6.8Ω 68Ω 680Ω 6.8kΩ 68kΩ 680kΩ 6.8MΩ 7.5Ω 75Ω 750Ω 7.5kΩ 75kΩ 750kΩ 7.5MΩ 8.2Ω 82Ω 820Ω 8.2kΩ 82kΩ 820kΩ 8.2MΩ 9.1Ω 91Ω 910Ω 9.1kΩ 91kΩ 910kΩ 9.1MΩ #generics #CommonPartsLibrary
    jharwinbarrozo
    1.5M
  • Generic Capacitor
    Generic Capacitor
    A generic fixed capacitor ideal for rapid circuit topology development. You can choose between polarized and non-polarized types, its symbol and the footprint will automatically adapt based on your selection. Supported options include standard SMD sizes for ceramic capacitors (e.g., 0402, 0603, 0805), SMD sizes for aluminum electrolytic capacitors, and through-hole footprints for polarized capacitors. Save precious design time by seamlessly add more information to this part (value, footprint, etc.) as it becomes available. Standard capacitor values: 1.0pF 10pF 100pF 1000pF 0.01uF 0.1uF 1.0uF 10uF 100uF 1000uF 10,000uF 1.1pF 11pF 110pF 1100pF 1.2pF 12pF 120pF 1200pF 1.3pF 13pF 130pF 1300pF 1.5pF 15pF 150pF 1500pF 0.015uF 0.15uF 1.5uF 15uF 150uF 1500uF 1.6pF 16pF 160pF 1600pF 1.8pF 18pF 180pF 1800pF 2.0pF 20pF 200pF 2000pF 2.2pF 22pF 20pF 2200pF 0.022uF 0.22uF 2.2uF 22uF 220uF 2200uF 2.4pF 24pF 240pF 2400pF 2.7pF 27pF 270pF 2700pF 3.0pF 30pF 300pF 3000pF 3.3pF 33pF 330pF 3300pF 0.033uF 0.33uF 3.3uF 33uF 330uF 3300uF 3.6pF 36pF 360pF 3600pF 3.9pF 39pF 390pF 3900pF 4.3pF 43pF 430pF 4300pF 4.7pF 47pF 470pF 4700pF 0.047uF 0.47uF 4.7uF 47uF 470uF 4700uF 5.1pF 51pF 510pF 5100pF 5.6pF 56pF 560pF 5600pF 6.2pF 62pF 620pF 6200pF 6.8pF 68pF 680pF 6800pF 0.068uF 0.68uF 6.8uF 68uF 680uF 6800uF 7.5pF 75pF 750pF 7500pF 8.2pF 82pF 820pF 8200pF 9.1pF 91pF 910pF 9100pF #generics #CommonPartsLibrary
    jharwinbarrozo
    1.5M
  • Generic Inductor
    Generic Inductor
    A generic fixed inductor for rapid developing circuit topology. *You can now change the footprint and 3D model at the top level anytime you want. This is the power of #generics
    jharwinbarrozo
    15.6k
  • Terminal
    Terminal
    An electrical connector acting as reusable interface to a conductor and creating a point where external circuits can be connected.
    natarius
  • RMCF0805JT47K0
    RMCF0805JT47K0
    47 kOhms ±5% 0.125W, 1/8W Chip Resistor 0805 (2012 Metric) Automotive AEC-Q200 Thick Film #forLedBlink
    jharwinbarrozo
    1.2M
  • 875105359001
    875105359001
    10uF Capacitor Aluminum Polymer 20% 16V SMD 5x5.3mm #forLedBlink #commonpartslibrary #capacitor #aluminumpolymer #radialcan
    jharwinbarrozo
    1.2M
  • CTL1206FYW1T
    CTL1206FYW1T
    Yellow 595nm LED Indication - Discrete 1.7V 1206 (3216 Metric) #forLedBlink
    jharwinbarrozo
    1.1M
Brainstorm a new project with AI [Example] thumbnail
Secure Classroom Handheld Student-Response Device

Properties

Pricing & Availability

Distributor

Qty 1

Arrow

$6.75–$12.20

Digi-Key

$15.97–$17.05

LCSC

$11.99–$12.51

Mouser

$18.85–$19.44

TME

$5.49

Verical

$3.92–$27.40

Assets

Brainstorm w Copilot.png

Brainstorm w Copilot.png

Brainstorm w CopilotThumbnail

Controls