NaoDec Build — Decision Record (Steps 3–9)

Date asked: 2026-07-14 · Date answered: 2026-07-14 Status: ✅ All answered. This file is now the decision record for the build work-instruction docs (NaoDec_Build_Step3…Step9). The answers below are folded into the step docs; residual unknowns each decision left open are flagged in the step docs' Open Items.

Background: items 1–3 were originally submitted as revision notes via the plan-approval dialog on 2026-07-14, but a session connection failure dropped the note text before it reached the assistant. This file exists so no decision can be lost that way again.

1. Node 0 vs "node 1" (cable entry point)

The LED mapping doc (NaoDec_3D_Vertex_and_Edges_LED_Mapping_Rev1.3.html) defines the common cable entry as Node 0 "POWER IN", a synthetic bus point below the base center; feeds fan out from it to base vertices v1–v5. The build outline says all cables "start from node 1" (v1 is the chair-facing vertex and the start of the vertex chain, circuits C1/C6, and the coil positive).

Answer: Node 0 is the controller unit itself. The original plan put the unit under the platform (hence the mapping doc drawing Node 0 below the base center). The current build places the controller unit outside the structure framework, ~2–3 m from node 1 (v1). The operator station and the Mac mini (controlling media: light, sound, vibration) are in the same area.

2. Audio hardware

Nothing in the repo documented the audio chain: 6 speakers (edges A, H, C, F, Y, M), the subwoofer, the 4 chair transducers, or any amplifier / audio interface out of the Mac mini.

Answer: Mac mini → 3.5 mm jack cable → subwoofer (direct). Mac mini → USB Type-C → Wondom GAB8 amplifier board, powered from 24 VDC. The GAB8 outputs drive the 6 speakers and 2 transducer sets (back set + seat set; 4 transducers total).

3. Series-coil routing

The series-coil / electromagnet subsystem (60 coils at the vertex units, pre-release Rev 0) was absent from the step outline, but its wiring shares the Node 0 → v1 path with the CH1 vertex LED chain.

Answer: The coils route along the same path as the vertex units → documented inside Step 3 (Vertex Units Installation), pre-release caveats retained.

4. Scent unit location

The outline placed "scent control" next to the subwoofer; the repo docs put the Waveshare board inside the controller box.

Answer: Only the atomizer/mist unit sits by the subwoofer. The Waveshare board stays inside the controller unit.

5. Controller unit contents

Answer:

1. LED Master + LED Slave (2× ESP32-S3)
2. The Waveshare (which is an ESP32-S3) → 3 ESP32-class boards total in the unit
3. The media playback controller's ESP32 is inside the media playback controller at the chair — a design change from the original in-unit plan, made because of the signal-wire issue (matches the Placement Requirement in NaoDec_Media_Playback_Controller_Build_and_Max_Setup.md §1). Its LAN cable runs from the router (inside the controller unit) to the chair and plugs into the W5500 module's RJ45.
4. The Mac mini is NOT inside the controller unit — it sits on a table, side-by-side with the unit.

6. + 7. Door hinge edge · Hinges at the other joints

Answer (combined): Every pentagon-panel edge gets 2 hinges — this is how the panels attach together rigidly. Only the edges resting on the ground/platform have no hinges (the 5 unlettered base edges). So all 25 lettered joints are hinged, 2 hinges each (50 hinges total).

Residual open item (flagged in Step 2): with all four of its lettered edges hinged, the mechanism by which the door (f11) opens — swing side, lift-off pins, or fully removable — still needs deciding.

8. Commissioning step

Answer: Add Step 9 — Commissioning & Test.

9. Clarified installation order + edge covers (added with the second revision message)

Answer: After all 11 pentagon panels are up:

1. Install the vertex units, routing all wires/cables
2. Install the internal edge units, routing all wires/cables
3. Install the speakers, routing all wires/cables
4. Move the scent control, subwoofer, and the chair in. Position the chair, then route all cables
5. Cover all the external edges with the edge covers — 25 pieces

Resulting step numbering: 1 Platform · 2 Structure · 3 Vertex Units · 4 Internal Edge Units · 5 Speakers · 6 Move-In · 7 Edge Covers · 8 Controller Unit Hookup · 9 Commissioning & Test.

10. Pictures in the docs (added via the plan dialog)

Answer: Mermaid diagrams + snapshots of the interactive 3D pages (no photo placeholders). Snapshots live in images/build/ and are generated headless from NaoDec_3D_Structure_Framework_Rev1.0.html and NaoDec_3D_Vertex_and_Edges_LED_Mapping_Rev1.3.html.