Idle & Burn-in Protection

OLED pixels that show the same legend for hours can burn in. To prevent that, PolyKybd moves through a few states while you’re away and wakes instantly the moment you come back.

The idle sequence

1. Awake — normal, full-brightness legends.
2. Fade — after the idle timeout (2 minutes unless you change it) the keycaps dim.
3. Idle — the displays run an anti-burn-in animation (see below).
4. Off — after 20 minutes without a key press the keycaps switch off entirely.

Any key press wakes them — and if the optional light sensor is fitted, so does reaching toward the board.

How long before it idles

Firmware protocol v18+idle timeout

How long the keyboard waits before it starts fading is a setting on the board — one of six fixed choices: 15 sec · 30 sec · 45 sec · 1 min · 2 min · 5 min.

2 minutes is the default, and it is what every keyboard did before this setting existed — so a board you never touch behaves exactly as it always has.

Set it in any of three places:

• On the keyboard — a key on the settings layer, behind More… (see the settings layer), next to the idle-style key. It shows a small clock face over the current value, so 2min on the keycap is the setting.
• Tray menu — right-click the PolyKybdHost tray icon → Idle Display → Idle After.
• Command line — polyctl idle-timeout 30sec (or 15sec, 45sec, 1min, 2min, 5min; with no argument it prints the current one).

Like the style, your choice is saved on the keyboard and survives a reboot and a reconnect.

Switching off is a separate, fixed timer

Picking a shorter timeout brings the fade and the idle animation forward. It does not move step 4 — the displays still switch off after 20 minutes without a key press, whichever timeout you choose. So 15 s gets you the animation sooner, not a keyboard that goes dark sooner.

Idle styles

Style	What it does
Pulse	Each key gently “breathes” its brightness out of phase with its neighbours. The lit pixels don’t move — simple, and the legend stays glanceable. The default on the split42.
Jitter	Keeps the breathing, but each key also relocates its legend to a fresh random spot whenever its own pulse dims it to black. The lit pixels migrate per key, so no pixel stays lit in one place.
Eden	A full-screen screensaver: a procedural “comet field” streams across all keycaps, with the key legend drifting over it as a dim overlay. Pretty rather than glanceable — the moving pixels give the strongest burn-in protection. The default on the split72.

Pulse and jitter keep the dimmed legend readable so you can glance down and resume typing; jitter adds stronger burn-in protection by moving the lit pixels. Eden trades that glanceability for a full moving picture — it’s a screensaver, so the pixels never rest in one place. Any key press dismisses it instantly.

Eden dims its drifting legend by lighting every other row rather than every row. Since firmware 0.17.3 that stripe pattern shifts as the legend moves, so the dimming itself no longer favours one set of rows for the life of the board.

Eden is split72 only

The Eden screensaver is drawn by code that only the split72 carries. On the split42 you can still select it, but nothing draws it — the legends just sit dimmed and motionless until the displays switch off, which is the one thing an anti-burn-in setting should never do. On a split42, use Pulse or Jitter.

Note

You can also replay the Eden animation once — as a boot-style intro rather than a loop — from the host or the EDEN keycode, whatever idle style is set.

Choosing a style

Firmware protocol v4+selectable idle style

• On the keyboard — a key on the settings layer, behind More… (see the settings layer). It names the active style rather than its own function — IDLE: on the first line, the current style on the second — so the keycap answers what is this set to without being pressed. Each tap moves to the next style.
• Tray menu — right-click the PolyKybdHost tray icon → Idle Display → Pulse, Jitter, or Eden.
• Command line — polyctl idle-style pulse (or jitter, eden).

Your choice is saved on the keyboard and persists across reboots.

Split72 owners updating from an older firmware

Eden became the split72 default in v0.17.0. Earlier firmware could not tell “I picked Pulse” apart from “I never picked anything” — both were stored as the same value — so a split72 that had never been switched to Jitter or Eden comes up in Eden once after the update. Set it back from any of the three places above and it stays put from then on.

Note

Each half runs its own idle animation on its own keys — only the style (pulse, jitter or Eden) crosses the split link. See Display power states for the full state machine.