WanderBand Family — Decision Log

Running log of every keep/swap/drop decision. Citations per entry.

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Stage 0 — Feature-parity sweep (2026-04-24)

• Decision: 4-tier family (Lite/Standard/Pro/Ultra) with modular sensor puck + shared Mini/Medium/Rugged chassis
• Source: competitive audit vs Apple Watch Ultra 3, Garmin Fenix 8, Samsung Galaxy Watch 7 Ultra, Oura Ring Gen 5, Whoop 5.0, Fitbit, Pixel Watch 4
• Flags: see _COMPETITIVE-AUDIT-2026-04-24.md (11 LEADS / 4 MATCHES / 6 LAGS)

Stage 1 — Intake + freeze (2026-04-24)

• Device IDs assigned: WV-WEAR-BAND-LITE / -STD-42 / -STD-46 / -PRO / -ULTRA
• Revision frozen at v1.0-candidate
• Ship target locked: Lite/Std 2027-Q3 · Pro 2028-Q1 · Ultra 2028-Q3

Stage 2 — Component selection (2026-04-24, Perplexity-validated)

Dual-SoC architecture confirmed (not single-SoC, corrected via Perplexity 2026-04-24):

• Ambiq Apollo4 Blue Plus — UI/app/display layer; power-optimized for AMOLED + wearables
• Nordic nRF5340 — BLE 5.4 connectivity + Zephyr RTOS anchor
• Why dual: Ambiq strongest for UI/power; Nordic strongest for BLE/RTOS; together they model what Apple/Garmin/Samsung actually do

Cellular modem (Pro/Ultra): Telit FN990Axx primary (Perplexity-validated — explicit AT&T + FirstNet + T-Mobile + Verizon cert). Quectel BG95-M3 alternate for ultra-compact form factor optimization. Sequans Monarch 2 tertiary.

WiFi client radio: on Standard+, integrated WiFi 6/6E via Ambiq/Nordic reference designs + MediaTek MT7925 alternate module path.

Sensor puck v1 components locked:

• HR PPG + HRV-PPG: Maxim MAX86141 multi-wavelength (upgrade from MAX30102 per Perplexity sensor audit)
• Accelerometer + gyro + IMU: InvenSense ICM-42688-P
• Skin temp: Texas Instruments TMP117
• Altimeter/barometer: Bosch BMP390

Sensor puck v1.5 additions (Pro+):

• SpO2: integrated in Maxim MAX86141
• ECG electrodes: Maxim MAX30003 analog front-end
• Bioimpedance: Analog Devices AD5940
• GSR/EDA: simple 2-electrode + op-amp circuit (low BOM)
• Air quality (Pro+ optional): Bosch BME688

Sensor puck v2 (Ultra 2028+, Pro 2028 upgrade):

• Non-invasive glucose: Rockley Photonics optical biosensor (hardware-ready slot; functional module ships when Rockley delivers — projected 2028-2030 per local LLM honest assessment)
• 24 GHz mmWave radar: Infineon BGT24LTR11
• 60 GHz mmWave radar (Ultra only): Infineon BGT60TR13C
• Thermal IR: Heimann HTPA 8×8

Chassis materials:

• Lite: injection-molded PC/ABS
• Standard: 6061-T6 aluminum CNC (anodized 3 colors)
• Pro: 316L stainless steel OR aluminum
• Ultra: Grade 5 titanium + sapphire crystal + PVD options + optional Ambassador walnut+brass bezel

Battery:

• Li-ion pouch (LCO/NMC) — only realistic chemistry for wearable energy density (Perplexity-confirmed)
• User-opens-with-T10 + adhesive seal (DIY possible; Ambassador-service default; waterproof warranty voids on DIY)
• Capacity: Lite 280mAh / Standard 400mAh / Pro 500mAh / Ultra 750mAh (with solar assist)

Display:

• Lite: 1.3" AMOLED 320×320, 600 nit, non-always-on
• Standard: 1.5"/1.8" AMOLED LTPO 420×420/480×480, 1000-nit peak, opt always-on
• Pro: 1.8" AMOLED LTPO 480×480, 1500-nit, sapphire, always-on
• Ultra: 1.92" AMOLED LTPO 502×410, 3000-nit sapphire + optional E-ink secondary display (v1.2+)

Stage 2b — Configurator axes (2026-04-24)

15 axes per tier including case size, cover material/finish, strap, sensor-puck tier, cellular option (Pro+), mmWave option (Pro+), dual-display (Ultra only), ambassador signature tier. See CONFIGURATOR.md.

Stage 3 — Compatibility review (2026-04-24)

Resolved:

• Ambiq + Nordic dual-SoC bridging via SPI + shared I²C (compatible with both vendors' reference designs)
• Sensor puck connector: 20-pin board-to-board hirose DF40 series (100+ cycle fatigue-rated)
• Antenna coexistence (BLE + WiFi + cellular + LoRa + GPS) — all separate bands + ground plane isolation
• Thermal envelope: Lite <1.5W, Standard <2W, Pro <4W, Ultra <6W (all fanless)

Deferred:

• Exact PCB impedance-controlled lane specs → Stage 5 Flux.ai + KiCad simulation
• GPS antenna placement (aluminum Faraday cage concern for Standard+ metal case) — antenna must be external or through sapphire window
• 60 GHz WiGig antenna coupling (Ultra only) — Stage 5

Stage 4 — Sourcing (2026-04-24, Perplexity-framed)

Same pattern as Bridge Mini: distributor RFQs needed for all components but framework is solid. Telit FN990Axx primary cellular; live RFQ pending. See SOURCING.csv.

Stage 5 — DFM/DFA/DFT (2026-04-24)

• Mainboard: 6-layer ENIG, 38×28mm typical (fits all case sizes); 8-layer for Ultra (higher density)
• Sensor puck: separate 4-layer board, 30×22mm, mates via 20-pin Hirose DF40
• Ambassador assembly time: 25-35 min/unit standard, 40-55 min Lux tier (per-unit biometric calibration + waterproofing seals + strap verification)
• DFT: 17 production tests per unit (biometric sensor validation, radio sanity, waterproofing pressure test, display pixel sweep)

Stage 6 — Thermal/EMC (2026-04-24)

• Fanless across all tiers (wearables require silent operation)
• Aluminum/titanium case acts as heatsink
• EMC: radio coexistence carefully isolated; FCC Part 15 C certification via MT7925 / Telit FN990Axx / Infineon mmWave modular cert passthrough
• ESD: Level 4 (±8 kV contact / ±15 kV air) on crown + buttons + charging pins + SIM slot
• IP rating: Lite IP67, Standard 5ATM, Pro 10ATM, Ultra 100m + dive

Stage 7 — Compliance (2026-04-24)

• Wellness-tier v1.0 launch: FCC + CE + UKCA + ISED + RoHS + REACH + Prop 65 = ~$15-25k
• FDA 510(k) v1.1 (Pro+Ultra 6-12mo post-launch): ECG + AFib ~$250-400k; cuffless BP v1.2 $200-500k
• Battery cert: UN38.3 + IEC 62133 + UL 1642 = $15-25k
• Cellular (Pro/Ultra): PTCRB + GCF + per-carrier = $15-25k
• Total v1.0 cert budget: $45-75k family-wide
• Total with v1.1/v1.2 medical-grade clearances: $400-800k over 18 months

Stage 8 — Canonical BOM + GUIDE + STLs (2026-04-24)

Platform + modules + 15 STL files (strap variants, charging dock, repair tools, display frame). See BOM-platform.csv, BOM-modules.csv, GUIDE.md, STL-OPEN-FILES/README.md.

Stage 9 — HW↔FW binding (2026-04-24)

• OS: Zephyr RTOS 3.7+ (WanderOS-Band overlay — MIT-licensed)
• UI: LVGL 9.x UI engine
• Alternate firmware: AsteroidOS / Wasp-OS flash compatibility (community-supported)
• HW rev ↔ FW image matrix per-tier; runtime sensor-puck detection

Stage 10 — Gate review + service flow (2026-04-24)

• EVT gate: 25 units per tier, 90% production-test yield required
• DVT gate: full cert runs, 95% yield
• PVT gate: first customer ship, 98% yield
• See GATE.md + SERVICE-FLOW.md

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Critical open items (revalidated)

Item	Severity	Action owner	Deadline
Rockley glucose partnership	🟡	Michael	before Ultra tape-out 2027-Q2
NTN satellite SOS partner	🔴	Michael	2026-Q3 outreach, 2027-Q1 commitment
MNO eSIM partnership	🔴	Michael	2027-Q2
Academic HRT research partner	🟡	Michael	2027-Q1
FDA pre-sub filing	🟡	Michael	2027-Q2
Contract manufacturer (wearable-class SMT)	🔴	Michael	2027-Q1
Engineering team hire (EE + FW + industrial design)	🔴	Michael	**NOW — 2026-Q3 start**