Skip to content

Engineered Lighting · Engineering notebook

Building the robotic spotlight

We're building the robotic spotlight for the Engineered Lighting fixture: a silent pan/tilt head (smart CAN servo motors, absolute encoders, no homing dance) carrying a high-CRI 3-up LED spot, living alongside the fixture's tunable-white ambient zones, exposed to Home Assistant as ordinary entities and aimed autonomously by a camera-driven perception stack — following people, lighting task surfaces and books, pointing at art when idle, never sweeping across eyes.

This seven-document series takes it from research through a working bench prototype to the system architecture, with everything adversarially reviewed and every purchase specified.

7 documents$475–850 end to endCurrent phase · parts ordering

What we're building toward

  • The silent robotic spotlight


    A pan/tilt head you can't hear: smart CAN actuators, absolute encoders, a balanced high-CRI LED payload — researched, chosen, and bench-built step by step.

    Docs 1–4

  • The aiming intelligence


    Cameras, ground-plane tracking, and beam self-calibration that follow people, light task surfaces, and never sweep across eyes.

    Doc 5

  • The system architecture


    The message contract every component obeys, and the software stack that runs it — testable without a living room.

    Docs 6–7

Buying parts?

Everything the series tells you to buy, in one interactive list — check items off as you order, progress and totals persist in your browser.

Open the BoM checklist

The document map

# Doc What it is You buy
1 How We Got Here Round-1 research digest: the physics, vocabulary, and five lessons under every later decision. Archive — read for understanding nothing
2 Choosing the Motors The decision journey to the RMD-L-4005 smart CAN actuators — what was evaluated, why integrated actuators won (decision feeds Doc 3)
3 Build the Gimbal 10-stage bench build: motors answering on CAN by stage 4, a balanced aimed head by stage 8. Full BoM, wiring, code, AI-partner workflow ~$185–290
4 Build the Full Fixture Bench One ESP32-C6 running the whole fixture: 21 tunable-white channels + CC spotlight + gimbal, in ESPHome/Home Assistant ~$170–240
5 Teach It to Aim The perception stack: cameras, ground-plane tracking, beam self-calibration, coordination, safety, user stories, phased roadmap (Phase 0 = a weekend) ~$120–320 per room
6 The Message Contract The one page every component obeys: topics, schemas, units, watchdogs, and the dual-control architecture (HA entities + autonomy without fights). When docs disagree, Doc 6 wins nothing
7 Building the Software The code: pinned stack, repo layout, hardware-free testing (replay cameras, simulated fixtures), deployment, firmware growth path, licensing gates nothing

Total prototype budget, all hardware: roughly $475–850 for one room end-to-end · Current phase: parts ordering / bench build