Hardware Design · BOM & Engineering Analysis · March 2026

Hardware Analysis

AI Story Companion Ecosystem — Full BOM, connector specification, thermal design, manufacturing considerations, and certification requirements for all five modular SKUs.

1. System Overview — Modular Architecture

🔵
Dome Projector
200×200×50mm · Fisheye ceiling · Passive cooling
€99
🎯
4 Sides Module
200×200×100mm · 4-wall sync · Active fan
€179
📽️
1 Projector Module
200×100×100mm · 1-wall entry · Passive
€79
🧊
AI Audio Cube
200×200×200mm · Battery · All AI
€129
🔌
Docking Station
200×200×30mm · Mains power · Ports
€39
Architecture principle: All intelligence lives in the AI Audio Cube. Projection modules are dumb peripherals — they receive power (12V/3A) and video (HDMI 2.0) over the magnetic connector and project frames. The Cube auto-detects which modules are attached and routes the correct video stream to each.

2. Module Connector Interface — Critical Specification

The magnetic pogo-pin connector is the most critical hardware design decision in the ecosystem. It must be robust to 1,000+ cycles, child-safe (no exposed pins, magnetic alignment), carry HDMI 2.0 bandwidth, and be manufacturable at low cost. Recommended: magnetic pogo-pin array with a mechanical locking ring.

SignalSpecBandwidth / RatingFunctionPins
PowerDC 12V / 3A per module36W max per connectorPowers projection modules via Cube battery when docked2 + shield
VideoHDMI 2.0 (TMDS)18 Gbps · 4K@30fpsSends rendered frames to each projector face19 (standard)
ControlI2C (400kHz)Fast modeModule enumeration, brightness control, on/off2 (SDA + SCL)
Frame SyncGPIO pulse (3.3V)<1ms cross-moduleSynchronises frames across all active modules1
ID / Detection1-Wire ID ROMModule type identification at hot-plug1
GroundCommon GNDReference4 (distributed)

3. AI Audio Cube — Core Device

The Cube is 200×200×200mm — the large form factor accommodates a larger battery, better speakers, and a robust connector area for stacking multiple modules. Connector faces: top (module output) and bottom (dock input). All intelligence is here — compute, battery, audio, camera, connectivity.

3.1 Full Bill of Materials

ComponentSelectionSpecCost (25K+ units)Notes
Compute SoMRaspberry Pi CM5 / i.MX 8M PlusQuad-core A55, 4GB RAM, NPU, GPU€30–40NPU for local ML
Microphone Array4-mic MEMS (custom PCB)Beamforming, 360°, 44.1kHz€6–10Key for child voice capture
Speaker AmplifierTPA3130 / MAX98357Class D, stereo 5W+5W€2–3
CameraSony IMX4775MP, 1080p30, wide angle€6–10Child detection, personalisation
Wi-Fi / BluetoothQualcomm QCN9074 / onboard CM5Wi-Fi 6, BT 5.3€3–5Dual-band for stability
BatteryLi-Ion 20Wh (5,400mAh @ 3.7V)UN38.3 certified, 4hr+ with Dome€14–18Must ship as UN38.3
PMIC + Charging ICTexas Instruments BQ25895USB-C PD 3.0, 18W charge€3–5
IMUICM-42688-P6-axis, motion + sleep detection€1.5–2
LED Ring16× WS2812B (diffused)RGB, story interaction feedback€2–4
Module Connector (top)Magnetic pogo-pin array (custom)HDMI + I2C + 12V + GPIO + ID€4–7Critical custom part
Dock Connector (bottom)Magnetic pogo-pin array (custom)12V power in + data€3–5
Main PCB (6-layer)Custom, 4oz copperHDMI routing, power planes€10–15At 10K+ volume
Enclosure (ABS)200mm cube, rounded cornersIP54, child-safe, drop-rated€16–22Tooling amortised
Assembly (CM labor)Contract manufacturerAt 10K+ units€12–15
PackagingBox + USB-C cable€4–6
Total BOM (25K+ units target)€95–130

3.2 Power States

StateActive ComponentsPower DrawBattery Life
Full Active + Dome moduleCPU + Audio + Camera + Wi-Fi + Dome~12W~4 hours
Story Playback (audio only)CPU + Audio + Wi-Fi~4W~5 hours
Sleep CompanionAudio (low) + IMU~1.2W~15 hours
Deep Sleep / Wake-word onlyPorcupine wake-word engine~0.08W~7 days

4. Docking Station

200×200×30mm flat base. Mains powered (100–240V AC). Provides 12V/3A to the Cube via the bottom connector. Side ports: USB-C (data), HDMI pass-through (for TV/monitor), power LED.

ComponentSpecCost
AC-DC Power Supply100–240V in → 12V/3A out, CE certified€6–10
Top Connector (to Cube)Magnetic pogo-pin, standard interface€3–5
USB-C Port + ControllerUSB 3.0, data only€2–4
HDMI Pass-ThroughHDMI 2.0, from Cube output€1–2
PCB (2-layer)Simple, low-cost€3–5
Enclosure (ABS)200×200×30mm, non-slip base€5–8
AssemblySimple BOM€4–6
Total BOM€24–40

5. Dome Projector

200×200×50mm. Houses a single pico projector pointing upward through a fisheye lens (≥160° FOV) that covers the full ceiling at 2.5m height. Fisheye distortion correction is applied entirely in the Cube's projection compositor. Passively cooled — silent at bedtime.

ComponentOptionSpecCost
Pico Projector ModuleDLP LightCrafter or equiv.720p, 200 lumens, compact DLP€25–38
Fisheye Lens (M12 mount, upward)Custom M12 mount≥160° FOV, equidistant projection€10–18
Lens Mount + Alignment BracketPrecision-mouldedFactory-aligned, no user adjustment€4–6
Passive HeatsinkAluminiumSufficient for 200-lumen DLP€2–4
Bottom Connector (magnetic pogo)Standard interfaceReceives power + HDMI + I2C€3–5
PCB (simple driver board)HDMI input → projector interface€4–6
Enclosure (ABS)Low-profile, ceiling-oriented aperture200×200×50mm€6–10
Assembly€5–8
Total BOM€59–95
Render mode: Cube generates 1× fisheye-distorted render stream → Dome projects → full ceiling coverage. Fisheye equidistant correction applied on-device.

6. 1 Projector Module

200×100×100mm. Single forward-facing pico projector for one-wall directional projection. The entry-level projection option. Keystone correction applied in the Cube's compositor automatically.

ComponentSpecCost
Pico Projector ModuleDLP, 720p, 150 lumens, compact€22–32
Wide-Angle Lens~80° FOV, rectilinear€5–8
Bottom Connector (magnetic pogo)Standard interface€3–5
Passive Heatsink€1–3
EnclosureSingle aperture front face€5–8
PCB + Assembly€6–10
Total BOM€42–66

7. 4 Sides Module

200×200×100mm. Four pico projectors facing N/S/E/W — all driven simultaneously by the Cube compositor with per-face keystone and edge-blending correction. Frame sync GPIO ensures <1ms offset across all four faces. Active cooling required for four simultaneous projectors.

ComponentSpecCost
4× Pico Projector ModulesDLP, 720p, 150 lumens each€80–120 (4×)
4× Wide-Angle Lenses~80° FOV, rectilinear€16–24 (4×)
HDMI Distribution IC4-channel HDMI splitter/router€6–10
Active Cooling (40mm fan)Required for 4× simultaneous projectors€4–7
Bottom Connector (magnetic pogo)Standard interface€3–5
Enclosure (ABS)4 aperture faces, ventilation slots€10–15
PCB (6-layer, complex routing)Power + HDMI distribution€14–20
Total BOM€133–201
Render mode: Cube generates 4× synchronized rectilinear render streams → HDMI distribution IC routes to 4 projectors → all 4 walls covered. Per-face keystone + edge blending applied in compositor.

8. Thermal Analysis

Total power draw at full stack (Cube + Dome + 4 Sides): ~36W system load. Each module has its own thermal path to ambient — the stack connector does not transfer heat between modules.

ConfigurationTotal PowerThermal RiskCooling Strategy
Cube only~4WNonePassive (Cube)
Cube + Dock~4WNonePassive
Cube + Dome~12WLowPassive (both)
Cube + 1-Proj~10WLowPassive (both)
Cube + 4-Sides~28WMediumActive fan (4-Sides)
Cube + Dome + 4-Sides (Full Universe)~36WMediumActive fan (4-Sides) + passive (Dome)

9. Certifications & Compliance

All five SKUs require CE marking for EU market sale. Note: each module may need separate CE/FCC testing. Engage test labs early in Phase 3 to avoid Phase 4 schedule risk.

CertificationApplies ToEst. CostTimeline
CE Mark (EU)All 5 SKUs€5–15K/SKU3–6 months each
EN 71 Toy SafetyCube + Dock€3–8K2–3 months
RoHS / REACHAll 5 SKUs€1–3K total2 months
UN 38.3 (Battery)AI Audio Cube€2–4K6 weeks
FCC Part 15 (USA)All 5 SKUs€5–10K/SKU3–4 months
COPPA / GDPR (Software)Platform€8–20K (legal)2–3 months
Budget Estimate: Total €50–90K for full EU certification across all five SKUs. Critical path: CE Mark and EN 71 are the longest lead-time certifications. Pre-compliance EMC testing should begin at DVT stage (Phase 3, Month 14). Prioritise Cube + Dock + Dome first for EU launch, then modules.