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+# Ecosystem
+
+Survey of prior art relevant to claude-gauge, captured during initial
+research in April 2026. Establishes what exists, what to borrow, and
+where claude-gauge can uniquely contribute.
+
+## Direct cousins
+
+Projects that do essentially the same thing claude-gauge does: a
+software metric driving a physical analog needle cluster.
+
+### Liam Jackson — CI Test Tachometer Dashboard
+
+The closest cousin. Three universal motorcycle tachometers wired to
+an Arduino, displaying continuous-integration test failure counts in
+real time. OLED in the center for context numbers.
+
+* Hardware: sub-$10 motorcycle tachs, Arduino, 3D-printed housing
+* Signal: frequency-based PWM (1000 RPM = 16.66 Hz), "Slow PWM"
+  library
+* Power: several hundred mA at high deflection
+* Source: Printables STL for the housing, code inline in the
+  Hackaday writeup
+* Reference: [Putting Cheap Motorcycle Tachometers To Work](https://hackaday.com/2025/01/18/putting-cheap-motorcycle-tachometers-to-work/)
+
+### John McLear — AstraDash (Astra GTE -> Home Assistant)
+
+Repurposed Astra GTE car dashboard driven by ESP32 showing Home
+Assistant sensor data. Every 5 s, MQTT pushes a JSON payload
+(`{oilTemp, battery, coolantTemp, fuelLevel, rpm, speedo}`) that gets
+mapped arbitrarily to home metrics. EV charge becomes fuel level,
+task count becomes speedometer, solar output becomes RPM.
+
+* Hardware: Astra GTE cluster, ESP32 NodeMCU-32S, bit-banged SPI
+* Integration: MQTT via Home Assistant
+* Source: [DNThomas/AstraDash](https://github.com/DNThomas/AstraDash)
+* Article: [A Dashboard Outside The Car](https://hackaday.com/2024/01/11/a-dashboard-outside-the-car/)
+
+Lesson: the `/usage` JSON shape we designed for the firmware is the
+same abstraction McLear uses. Validates the architecture.
+
+### Evan — Kegerator Gauge Cluster
+
+Salvaged Chevy cluster driving analog meters that show beer temp and
+"fuel" (keg volume). Pressure sensors on a scale beneath the keg,
+plus a flow sensor on the tap line. LEDs for drama during pour
+events.
+
+* Pattern: automotive cluster as purpose-built hobby display
+* Reference: listed on Hackaday under the gauge-cluster tag
+
+### Steampunk voltmeter projects
+
+Widespread Home Assistant community pattern: repurpose vintage
+voltmeters as ambient displays via ESPHome. PWM driven through an RC
+low-pass filter to smooth the needle. Used for tank levels, battery
+state, network load, etc.
+
+* Pattern: ESPHome + vintage meter body = instant Home Assistant
+  integration
+* Reference: Home Assistant community threads on MQTT DC voltmeters,
+  analog gauge dashboards
+
+## Adjacent projects
+
+Same hardware pattern (ESP32 + display + metric), different data or
+display choice.
+
+### Ecasti — PrometheusClient
+
+Probably the most interesting adjacency. ESP32 pulls from Prometheus
+via HTTP and renders time-series graphs, gauge displays, and stat
+panels on integrated LCDs (M5Stack Tab5 / AtomS3 / CoreS3). Supports
+HTTPS and Grafana Cloud. Apache-2.0.
+
+Studying the HTTP query loop and caching patterns saves real
+daemon-design time. The digital cousin of claude-gauge; swap the
+displays for steppers and you're at claude-gauge.
+
+Source: [ecasti-gmail-com/PrometheusClient](https://github.com/ecasti-gmail-com/PrometheusClient)
+Article: [Prometheus Dashboards on ESP32](https://www.hackster.io/ecasti/prometheus-dasboards-on-esp32-d590db)
+
+### r00li — CarCluster
+
+Drives real automotive instrument clusters from a PC via ESP32.
+Primary use case: driving simulators (Assetto, Forza). Bit-bangs SPI
+to the target cluster.
+
+Source: [r00li/CarCluster](https://github.com/r00li/CarCluster)
+
+### YouTube / Twitch subscriber counters
+
+Pattern well-represented but exclusively digital: MAX7219 matrices,
+OLEDs, 7-segment. No physical-needle variants found. Example:
+[joeybab3/Live-Subscriber-Counter](https://github.com/joeybab3/Live-Subscriber-Counter).
+
+### Bitcoin / crypto tickers
+
+Similarly digital-only. OLED + API fetch every N seconds. A GitHub
+project [sandman72/ESP32_BitcoinMeter](https://github.com/sandman72/ESP32_BitcoinMeter)
+hints at a meter variant but isn't widely built.
+
+### Classic-car instrument restorations (Triumph GT6, Alfa Giuletta)
+
+Replace mechanical gauges with LCD. Different problem shape; not
+applicable.
+
+## Hardware building blocks
+
+### SwitecX25 driver library
+
+The canonical Arduino library for X25, X27.168, VID28, VID29,
+BKA30D-R5 steppers. Direct GPIO, no external driver IC strictly
+required (though ULN2003A recommended for cleaner current).
+
+Source: [clearwater/SwitecX25](https://github.com/clearwater/SwitecX25)
+
+### Reference Arduino X27 build
+
+Full working Arduino code and wiring for X27 stepper + OLED overlay.
+
+Source: [nsocwx/Digital-Speedometer](https://github.com/nsocwx/Digital-Speedometer)
+
+### TheRengineer Analog Gauge Stepper Motor PCB
+
+Pre-made driver board for X27.168 / VID28 with JST connectors.
+Skips the breadboard stage.
+
+Source: [Tindie listing](https://www.tindie.com/products/TheRengineer/analog-gauge-stepper-motor-pcb-only/)
+
+### Universal motorcycle tachometers
+
+$5-10 on overseas retailers. 12 V nominal but respond to 5 V logic.
+Frequency-driven (1000 RPM = 16.66 Hz). Larger and more visually
+readable at desk distance than X27.168. Good V1 prototype path.
+
+### Vintage analog voltmeters
+
+Etsy listings for Bakelite-body industrial voltmeters, steampunk
+aesthetic ready. Typical $10-30. Drill for wiring, repurpose the
+movement, done.
+
+## Middleware and framework options
+
+### ESPHome
+
+Home-Assistant-native framework for driving PWM-controlled analog
+meters. If the claude-gauge daemon exposes a Home Assistant sensor,
+ESPHome handles the firmware layer automatically.
+
+Trade-off: less firmware control, faster path to a moving needle.
+Worth prototyping on.
+
+### Grafana Labs dashboard 25052
+
+Pre-built Claude Code metrics dashboard. Free deep-stats surface for
+architecture A. Import against Prometheus; done.
+
+### Anthropic `claude-code-monitoring-guide`
+
+Official reference Docker Compose stack: OTEL collector + Prometheus
++ Grafana. Borrow wholesale for architecture A.
+
+Source: [anthropics/claude-code-monitoring-guide](https://github.com/anthropics/claude-code-monitoring-guide)
+
+## Aesthetic references
+
+* **Retro-futuristic automobile control panel** (Hackaday.io project 10579): 1960s dashboard with modern guts.
+* **Daniel Lazo's Retro Digital Dashboards** (Behance): art direction for cluster visuals.
+* **Dieselpunk cellphone** (Make Magazine): aesthetic coherence lesson.
+* **Bakelite industrial voltmeters** (Etsy): housing reuse options.
+
+## Curated lists checked
+
+* [obazoud/awesome-dashboard](https://github.com/obazoud/awesome-dashboard) — software dashboards
+* [pfalcon/awesome-smarthome](https://github.com/pfalcon/awesome-smarthome) — smart home ecosystem
+* [GitHub ambient-display topic](https://github.com/topics/ambient-display) — mostly e-ink
+
+Physical-gauge variants are under-represented in curated lists,
+which itself is a signal.
+
+## Where claude-gauge uniquely contributes
+
+| Axis | State of the world | claude-gauge angle |
+|---|---|---|
+| Data source | HA, CI, kegerator, car sim, crypto | LLM telemetry (first) |
+| Gauge metric | RPM, temp, fuel, voltage, follower count | Thinking-to-output ratio (novel) |
+| Cluster semantics | Repurposed car cluster w/ mental legend | Purpose-built for token flow (new) |
+| Model indicator | n/a | Discrete annunciator for active model (new) |
+| Data path portability | Locked to one source | Dual-architecture (OTEL or ccusage) |
+| Enclosure | One-off bespoke | Open, printable, replicable |
+| Character metrics | n/a | Em-dash violator counter, phrase extractor |
+| Physical observability framing | Implicit | Explicit "make AI work tangible" |
+
+## What to borrow
+
+1. **Motorcycle tachometers** as the V1 prototype hardware. Ship a
+   working needle in a weekend before committing to X27.168.
+2. **McLear's JSON-over-MQTT payload abstraction**. Confirms the
+   firmware contract is right.
+3. **Ecasti's PrometheusClient** HTTP query loop and caching patterns.
+   Lift directly for the daemon.
+4. **TheRengineer's driver PCB** to skip X27.168 breadboarding.
+5. **ESPHome firmware** as a shortcut path; fall back to hand-rolled
+   Arduino only if needed.
+6. **Vintage Bakelite voltmeter case** from Etsy: one industrial box
+   housing all four needles, drilled ports. Instant aesthetic win.
+7. **Grafana dashboard 25052** verbatim for architecture A's deep
+   stats.
diff --git a/Home.md b/Home.md
index 699e52e..0ca914b 100644
--- a/Home.md
+++ b/Home.md
@@ -22,9 +22,11 @@ the ambient summary.
   `ccusage` integration for B, Claude Code env vars
 * [Hardware](Hardware) — cluster layout, X27.168 steppers, ESP32
   wiring, firmware structure, enclosure
+* [Ecosystem](Ecosystem) — prior-art survey, what to borrow, where
+  claude-gauge uniquely contributes
 * [Roadmap](Roadmap) — phases, shipped, deferred
-* [Ideas](Ideas) — exotic variants, metrics brainstorm, parked
-  thoughts
+* [Ideas](Ideas) — exotic enclosure variants, unique-angle
+  shortlist, metrics brainstorm
 
 ## At a glance
 
diff --git a/Ideas.md b/Ideas.md
index ea1eff4..fd07280 100644
--- a/Ideas.md
+++ b/Ideas.md
@@ -149,22 +149,69 @@ lands on Grafana panels or a custom web page later.
 * Fitbit / health data: Claude usage vs heart rate (do you actually
   stress out when Claude is slow?)
 
-## Hardware wild ideas
+## Unique-angle shortlist
 
-* **Audio feedback**: a quiet relay-click when the tach crosses
-  redline; a chime when a 5h block resets. Could be annoying;
-  prototype with speaker off first.
-* **Tactile feedback**: a small vibration motor in the bezel that
-  pulses when STALL lights (useful if the cluster is out of your
-  peripheral vision).
-* **Per-project LEDs**: a strip beside the cluster where the lit
-  LED indicates which project is currently active. Fun for homelab
-  archaeology.
-* **Second cluster on the other monitor** showing a 24-hour sparkline
-  rather than live gauges. Historical companion.
-* **Cluster-to-cluster sync**: if claude-gauge becomes popular enough
-  to build for friends, a single OTEL collector could drive multiple
-  clusters in multiple homes. Niche but fun.
+Directions other projects haven't taken. Each plays on the dual
+nature of a cluster: always-on display AND potential input surface.
+
+### Physical model-selector knob
+
+Rotary encoder mounted on the bezel that forces the model for the
+next prompt. Turn clockwise through Haiku, Sonnet, Opus; click to
+lock. The MODEL annunciator LED preview-lights while turning,
+solid-lights once the next prompt lands.
+
+Turns the cluster into an input device, not just a display. No
+prior art.
+
+### Swappable faces per mode
+
+Gauge faces are magnetic and swap in under a minute. "Scientific"
+mode has numbered scales; "Brand" mode has model logos; "Mood" mode
+is colour-coded emotional labels; "Seasonal" mode is themed. Same
+needles, different semantics. Conference demo catnip.
+
+### Daily reset chime
+
+Real brass bell or solenoid click when a 5h block resets. Pavlov
+for token management. Off by default; opt in per-user.
+
+### Tactile feedback
+
+Small vibration motor in the bezel that pulses when STALL lights.
+Covers the "is Claude alive" question when the cluster is out of
+peripheral view.
+
+### Per-project LED strip
+
+RGB strip beside the cluster; the lit section indicates which
+project is currently active. Turns the desk into an ambient
+work-location indicator for ADHD self-awareness.
+
+### Cluster-to-cluster sync over LAN
+
+If claude-gauge ships to friends, multiple clusters around the
+country sync to a shared OTEL collector showing aggregate usage.
+"Claude Code Live" art piece.
+
+### Physical commit button
+
+Satisfying mechanical clicky on the cluster bezel that triggers a
+pre-composed `git commit` in the current project. Cluster as input
+AND output. Dangerous, fun, on-brand. Requires daemon-side
+permission gating.
+
+### Audio feedback (optional)
+
+Quiet relay click when the tach crosses redline; chime when a 5h
+block resets. Off by default. Some users will love it, some will
+throw the cluster out a window. Make it a toggle.
+
+### Second cluster as historical companion
+
+A second, smaller cluster on the other monitor rendering a 24-hour
+sparkline rather than live gauges. Paired-instrument aesthetic.
+Overkill for one user, charming for an office.
 
 ## Software wild ideas