Screen settings

Where these settings live

Open Screens and click a screen. Most of the page is the scene editor — the canvas, the widget palette, the layers list — and those belong to the scene you happen to be editing rather than to the screen. They are covered in the scene articles.

This article is about the rest: the two right-hand menus in the toolbar, and the panels down the right-hand column below the schedule. Those settings belong to the display itself and follow it whichever scene it is showing.

There is a difference in how they save, and it catches people out. Scene layouts and the schedule are held until you press Save & push. The screen's own settings — shape, rotation, presence, gestures — are sent the moment you change them, with no Save button anywhere near them.

The screen's name

The name is set when you pair, in the Screen name box. It is the heading of this page, the label on the Screens list, and what appears on the wall for five seconds when you press Identify screen.

You can change it later. Each card on the Screens list has a Rename button, and the new name reaches the wall straight away — the screen is told to reload, so it stops calling itself by the old one when you press Identify. The change is recorded in the audit log with both names. It is still worth a second's thought at pairing: Kitchen and Hallway are useful five screens later, Screen 2 is not.

Shape — what the panel actually is

The shape menu is labelled with the current size, or with Landscape or Portrait when no size is set. It answers three questions at once: what grid a scene is laid out on, what shape the editor canvas and the live preview draw, and — if you draw floor plans — which way round this panel is drawn on them. A plan draws each screen at the real size it was given and swaps its width and height when this setting says portrait, which is how a door panel reads as a door panel. The plan shows Portrait or Landscape beside the size but will not let you change it there: a panel's shape is decided here, and a second place to answer the same question could only disagree with the first.

The grid is always twelve columns. Landscape gives you eight rows, portrait eighteen. Setting an exact pixel size does not change the grid — it changes the proportions of the canvas, so that what you arrange in the editor is the shape of what appears on the wall. Without it Mirra assumes 16:9, and a 1024 × 600 Pi display arranged against a 16:9 canvas comes out subtly wrong in a way that is hard to name and easy to see.

1. Open the shape menu

   In the toolbar, the menu showing the current size or orientation.

2. Choose the panel you actually have

   Pick a preset if it is listed, or Custom size… if it is not. The orientation follows from the size — you do not set it separately.

3. Let the scenes reload

   If the shape changed between landscape and portrait, Mirra reloads the scenes so the editor is drawing on the right grid. If you have unsaved changes it warns you first.

4. Check the canvas against the wall

   Turn Preview on and compare. The canvas is a scale model of the panel, so anything that overflows here will overflow there.

A size from the list

Ten common panels: 1920 × 1080, 3840 × 2160, 2560 × 1440, 1366 × 768, 1280 × 800, 1024 × 600 and 800 × 480 in landscape, and 1080 × 1920, 2160 × 3840 and 1200 × 1920 in portrait. Choosing one sets the orientation to match — a panel wider than it is tall is mounted landscape, and that is not a choice anybody gets to make.Default: Nothing chosen; a newly paired screen has no size set

Custom size…

For a panel that is not on the list. Mirra asks for it as width x height and takes whole pixels between 320 and 8192 each way; anything else is refused. It sets only the shape the editor and preview draw — it does not change the display's own resolution.Default: The box is filled with the current size, or 1920x1080

No exact size — just landscape

Clears the size and lays scenes out on the landscape grid, twelve columns by eight rows, with the canvas drawn 16:9.Default: Where a newly paired screen starts

No exact size — just portrait

Clears the size and lays scenes out on the portrait grid, twelve columns by eighteen rows, drawn 9:16.

Changing between landscape and portrait re-flows every scene that was drawn for this screen and is used nowhere else — widget heights and vertical positions are scaled to the new number of rows rather than reset. A scene shared with another screen is left exactly as it is and re-flowed only on its way to this display, so re-mounting one screen cannot rotate somebody else's wall. Unsaved layout changes are lost when the scenes reload; Mirra warns you before it does it.

Which way up — the turn

Orientation says what shape to lay a scene out in. Rotation says which way up the panel is. Only the two together describe a real wall: a monitor turned on its side is portrait whichever way you turned it, and turned the wrong way the picture is upside down. Orientation alone has no word for that, which is why choosing portrait used to leave people staring at a squashed landscape picture.

This menu deliberately does not touch your layouts. Somebody using it is standing in front of the wall pressing a button until it looks right, and having their scenes rewritten as a side effect of straightening a monitor would be a nasty surprise.

Automatic — match the layout's shape

Turns the picture only when the layout's shape disagrees with the shape of the viewport the browser actually has. A Pi whose compositor is already rotated is left alone; one that is not gets turned in software, so neither ends up rotated twice. What it cannot know is which way the panel was physically turned, so it always turns clockwise — which is why the three fixed options exist.Default: Automatic

90° — turned clockwise

A quarter turn clockwise. The one to choose for a monitor rotated so its original top edge is now on the right.

180° — upside down

For a display mounted the other way up. The viewport keeps its shape; only the picture turns.

270° — turned anticlockwise

The other quarter turn — what to choose when 90° comes out upside down.

A turn is sent straight away, but the display only obeys once it has fetched its new configuration, so allow up to a minute and use Reload screen if it has not moved. A display running an older build of the screen app ignores rotation entirely. One honest wrinkle: this menu shows Auto again after you reload the page, because the page does not read the stored turn back. What the label says after a reload is not evidence of what the screen is doing — the display keeps whatever you last set until you change it.

The camera, and everything that hangs off it

The Presence panel is one switch and a set of qualifications on it. Nothing here does anything until the camera is on, and the camera is off on a new screen.

Recognition runs on the display itself. Camera frames and the face descriptors taken from them never leave it; what travels is at most "this person appeared".

Camera on this screen

The master switch. Off means Mirra never asks the browser for the camera, and everything that reads the room — recognising people, greeting them, gestures, and widgets set to show only when somebody is there — does nothing. A widget with a presence rule falls back to always showing rather than never.Default: Off

Control it with gestures

Wave left or right to move through photos and art; hold up an OK sign to choose. Read on the display, like recognition, and no images leave it. The switch is disabled until the camera is on, and the server refuses it anyway: "Turn the camera on for this screen first — gestures read from it."Default: Off

How readily it responds

Only big, deliberate waves / Normal / Responds to less. In a busy room choose the first — the cost of the last is the occasional wave nobody meant, and a gallery that jumps because somebody reached past is worse than no gestures at all.Default: Normal

Direction

Wave right to go forward, or wave left to go forward. A front camera sees you unmirrored, so your hand moving to your right moves left across the image. The default assumes the usual mounting; if it goes the wrong way, switch this.Default: Wave right to go forward

Greet people automatically

Whether a recognised person is greeted without being asked. Off leaves recognition working and stops the screen speaking first — which is what a screen in an office wants and a screen in a hallway does not.Default: On

Linger (s)

How long somebody must stay in view before they are greeted. It is what stops the screen talking to a person walking past. Between 1 and 30 seconds.Default: 3

Cooldown (min)

The quietest gap between greetings for the same person, so it does not greet you on every trip to the kitchen. 0 greets every time. Up to 1440, which is a day.Default: 90

Quiet from / Quiet until

Greetings are suppressed between these two times. This is the setting that makes a screen in a bedroom bearable.Default: 22:00 to 06:30

Scene when someone's here

Switch to this scene while somebody is in front of the screen. Don't change leaves the schedule to decide.Default: Don't change

Scene when the room's empty

Switch to this scene when the room has been empty for a while — an art frame, or something dimmer. Don't change leaves the schedule to decide.Default: Don't change

These save as you change them; a small Saved ✓ appears rather than a button. Two related settings are not on this page: how long the room must be quiet before it counts as empty, which is ninety seconds, and which of the two gestures are enabled, which is both. Mirra refuses to save gestures with neither the wave nor the hand sign turned on, because that is a switch that appears to be on and does nothing.

Sleeping, blanking and burn-in

Mirra has no sleep setting, no blanking setting and no dim setting. This is worth saying plainly, because it is the first thing people look for.

A Mirra screen is a browser page. Whether the panel goes dark is decided by the machine underneath it and by the display's own timer, and Mirra has no way to reach either. The Raspberry Pi installer stops the screen blanking as part of setting the machine up, which is what a wall display wants. A laptop will still sleep, run its screensaver and install updates. A smart TV will often close the browser or sleep on a timer, and nothing will restart it — turn that timeout off before you rely on the TV for anything.

If what you want is for the screen to be different at night rather than off, the tools are the scheduler — a dark scene from 22:00 — and a widget's own When to show window. Both change what is drawn rather than whether the panel is lit.

Screen commands

Four buttons that act on the display rather than on its settings, plus a row of face buttons underneath. They need the screen to be online; a screen that has gone offline cannot be reached by any of them.

Identify screen

Puts this screen's name on the wall for five seconds. The way to be certain which of four identical panels you have open before you change anything.

Reload screen

Reloads the browser on the display. The first thing to try when a change has not arrived, or when the screen has been up for weeks.

Run diagnostics

Asks the screen what it can see and prints its answer: the app build, how many minutes it has been up, the round trip to Mirra or "unreachable", and the last forty warnings and errors it has logged. Alongside it, what the screen measured about itself — whether it can play protected audio, its cores, its memory and its graphics renderer.

Sign in to a calendar on this screen

Starts a Microsoft sign-in from the wall. A short code appears on the display and here, and you finish on a phone at the address shown. Cancel takes the code off the display straight away — a screen left showing a dead code is the failure people actually notice. It depends on Microsoft sign-in being configured for your Mirra installation; where it is not, the button answers "Microsoft sign-in isn't configured." and nothing goes on the wall.

Assistant face test

Six buttons — dormant, summoned, listening, thinking, speaking and dismissing — that send the face straight to that state so you can see what it looks like on the real panel rather than in a preview.

The screen keeps the warnings and errors it has logged since it booted, as a rolling buffer of the last hundred and twenty lines, and that buffer is the only thing in Mirra that knows why a connection to something on your network failed. Ordinary chatter is not captured, so a hundred routine messages cannot push out the one line that matters. Nothing in the report reads the page, the photographs, or anything your household put on the screen.

Unpairing

Danger zone, at the bottom of the right-hand column, holds one button. Unpair screen removes this display from your household and returns it to showing a pairing code. Mirra asks to confirm first.

It is the right move when a screen is being retired, moved to another household or sold on. It is the wrong move as a way of fixing a screen that has gone blank or stale — reloading it costs nothing and loses nothing, and unpairing costs you the screen's settings and its scene list.

Unpairing deletes the screen record, so everything on this page goes with it: shape, rotation, camera and gesture settings, schedule rules and which scenes this display showed. The scenes themselves stay in your household, but only a shared scene can be added to another screen afterwards. Pairing the same display again produces a new screen rather than the old one back.