— Phase 0 — Concept & Parts Decisions

• Started: Raspberry Pi vs. ESP32 debate.
• Explored a Raspberry Pi + ReSpeaker 2-Mic HAT as the voice satellite. Realized the HAT is Pi-only (40-pin header) and won’t work with an ESP32 — this ruled out the “Pi does everything” plan.
• Landed on the cheaper, more local-first split: an old laptop as the always-on brain (free — already owned) + an ESP32-S3 as the voice satellite (~$4–15 in parts). ESP32-S3 was chosen over a plain ESP32/C3 specifically for its dual I2S channels and on-chip NPU for local wake-word detection.
• Finalized parts list: ESP32-S3 N16R8 dev board, INMP441 I2S mic, MAX98357A I2S amp
  (Adafruit), small speaker, jumper wires/breadboard.
• Setback: Amazon shipped the wrong board — a WROOM-32U instead of the ordered
  S3. Had to wait on a replacement before hardware work could start. (Kept the WROOM
  as a backup board — not wasted.)
• AI brain decision: start on Gemini’s free tier, with Claude API earmarked as a future
  paid upgrade if tool-calling reliability becomes a bottleneck. Confirmed early that the AI
  model is just a swappable dropdown in Home Assistant’s Assist pipeline — no hardware
  dependency either way.
  — Phase 1 — Sourcing the Speaker Driver
• Instead of buying a new speaker, salvaged a driver from a Bose SoundDock Twiddler
  (part 273488-004, ~4Ω) and wired it to the MAX98357A’s screw terminals — one of two
  available drivers from the dock.
• Briefly investigated repurposing the camera from a VTech DX2 kids’ smartwatch for afuture vision feature. Dead end: the sensor is proprietary and hardwired directly to the watch’s chip with no standard interface — not worth extracting. Filed away 4K camera /ESP32-CAM / USB webcam as real alternatives if a vision feature happens later.