Screen Brightness — tdlidar_brightness

Steal the phone’s own brightness slider and use it as a spare 0–1 fader for anything in your scene.

Category: Device · Tier: Free · Needs: any iPhone (no special hardware)

What it does

Streams the phone’s screen brightness as a single 0–1 value. On its face it tells you how bright the display is, but its real use is as a free hardware fader: the brightness slider in iOS Control Center is smooth, always available, and tactile, so you can repurpose it to drive any parameter in TouchDesigner without building a custom control surface.

OSC in

| address | type | range | rate | |—|—|—|—| | /tdlidar/device/brightness | float | 0–1 | 2 Hz |

Outputs

  • out1 (CHOP) — one channel: tdlidar/device/brightness (0–1).

Parameters

| par | default | what it does | |—|—|—| | OSC Port | 9000 | UDP port to listen on (match the app) |

Quick start (beginner)

  1. Enable device sensors in the app.
  2. Drop tdlidar_brightness.
  3. Drag the brightness slider on the phone (Control Center) and watch out1 glide 0→1.
  4. Export out1 onto any TOP/SOP parameter to use it as a live fader.

Advanced patterns

  • Spare fader (the point of this op): Math/Range CHOP remap 0–1 to whatever range your parameter needs — e.g. 0–1 → 0.5–4.0 for a feedback gain, or 0–1 → 0–360 for a hue rotate.
  • Smooth the steps: updates arrive at 2 Hz, so the raw signal stairsteps. Put a Lag/Filter CHOP after it (lag ~0.3 s) before driving anything visible, or it will feel notchy.
  • Detents: if you want discrete stops instead of a continuous fade, run it through a Math CHOP (floor(value*N)/N) to quantize to N steps you can feel on the slider.
  • Pair with another sensor: use brightness as the amount and a gesture/beat as the trigger — brightness sets how strong an effect lands when an onset fires.

Gotchas

  • 2 Hz only — it is not a per-frame control. Always Lag/Filter it before it touches anything the audience sees.
  • iOS auto-brightness will move this value on its own as room light changes; turn auto-brightness off on the phone if you want it to behave purely as a manual fader.
  • Raising brightness drains the battery faster — watch tdlidar_battery if you park the slider near 1 for a long install.