IntelliThings

Hardware — Hardware Subteam

Lead: @LiamWatson-Purdue · 7 people · owns Rig H

The breadboard rigs, the pin map, power design, the custom PCB and the 3D-printed enclosure for the three final sensor nodes. Design reasoning: Hardware_BOM_Candidates.md · per-part specs: Full_Parts_List.md · spending and build plan: Project Guideline §3 and §7.

Scope

• Build Rig H and Rig S from one wiring diagram so they stay identical; own the pin map (shared with Software)
• Pre-power checks: DWIN display set to TTL mode, 8-pin pinout confirmed, LD2410C supply voltage confirmed
• Power design; measure real current draw on the rig
• Compare the two WS2812B strips and pick one for the final bar
• Final PCB: schematic → layout → design review → JLCPCB order → SMT assembly of 3 nodes
• Enclosure design and 3D printing ×3

The node

7–8 pins, 2 UARTs. On the DevKitC-1 avoid GPIO12/13 (USB-JTAG) and 16/17 (UART bridge); don't put the LED data line or LD2410C OUT on strapping pins GPIO4, 5, 8, 9, 15.

Power

Rails: 12 V display · 5 V PMS5003, LD2410C, LED bar · 3.3 V ESP32-C6 + I2C sensors. Input is 12 V (buck to 5 V) or 5 V (boost to 12 V for the display) — chosen during PCB design. The LED bar dominates the 5 V budget (~60 mA per LED at full white). Common ground everywhere.

Final PCB

• MCU: bare ESP32-C6 chip if time allows; fallback: the DevKit plugged into female headers (or soldered to male headers). Decided at the Oct 25 layout session — switch to the fallback rather than slip the order.
• Option: split into sensor / ESP / connector-power boards (each its own KiCad project; board-to-board pinouts become contracts in docs/interfaces/).
• Copy pull-ups, decoupling and regulators from the Adafruit breakout reference designs.

Placement rules: SHT41 and SCD41 away from heat (ESP32, converters, backlight) · clear PMS5003 air inlet and outlet · windows for VL53L0X and BH1750 · no metal or ground pour in front of the LD2410C · antenna keep-out for the bare chip or DevKit.

Dates: schematic by Oct 18 · layout by Oct 25 · design review and JLCPCB order Nov 1 (~7 days to DHL delivery, +~1 day with a stencil) · 3 nodes assembled by Nov 15.

KiCad collaboration

• One board, one KiCad project, split into hierarchical sheets: Power · MCU · I/O.
• Each sheet has one owner at a time (assigned through Issues). Never two people on the same sheet at once.
• Keep every symbol and footprint in project-local libraries under hardware/.
• Agree before changing: GPIO assignments, I2C addresses, UART use, voltage levels, power requirements, connector types and pinouts, board placement.
• Layout: review the schematic together, confirm footprints and stock, 2–3 people route, everyone else reviews datasheets/footprints/DRC, final team design review before ordering.

What to commit

Yes: schematics, layouts, CAD source, BOMs, datasheets. No: gerbers, STLs, autosave/backup files — all re-exportable, all gitignored. Anything over ~10 MB, ask in Discord first.

Branches: hardware/power-input, hardware/mcu-bare-chip, hardware/io-sensor-bus, hardware/led-bar. See CONTRIBUTING.md.