Affordable signage for five screens with no subscription

What the setup has to do

Your requirements list has three lines:

1. The TVs switch on and off on their own.
2. The content starts playing the moment a screen wakes.
3. Updating the images beats pulling USB drives off wall brackets.

A TV's built-in slideshow app covers the pictures and misses the rest. On most models the app starts only after someone wakes the TV and opens the app by hand. The TV's own timer can switch the panel on, but that lands the screen on the TV's home menu with the slideshow unopened, so the morning walk survives intact.

The job you are describing belongs to a player. HDMI-CEC is the control channel built into the HDMI specification: a source device can send power-on and standby commands to the screen over the same cable that carries the picture. A player with a schedule in it turns its TV on before doors and off after close, day after day, without a remote. The mechanics are in how HDMI-CEC signage display control turns a screen on and off, and the two-times-a-day detail is in scheduling screens on and off over CEC from a signage player.

The setup that fits: one card player per screen

Buy five small media players, one per TV. Each one holds a memory card with the same three PNG files, is set to start playback at power-up, and carries the daily on and off times that it sends to its TV over CEC.

The pieces, in order:

• A short HDMI run from each player to its own TV.
• Identical cards, so any card works in any player and a failed card is a quick swap.
• The on and off times live in the players, so the TV menus stay untouched.

Updating is a desk job with a walk at the end. Copy the three files onto one card, duplicate that card to the other four, then make one round through the room. If a slide needs text or layout work first, the program that makes content for a USB offline sign covers the making step. Retire any image on its own date: a slide that names a promotion or an opening day comes off the card that day, and the content expiry checklist for offline playlists is the routine to copy. For where fees hide in this class of equipment, the guide to no-subscription signage goes through the whole picture.

Your options compared

Example: a schedule for five screens that open at 10:00

This works one venue's day end to end. Change the hours to yours and the method holds.

Inputs: five screens showing the same three PNG images; doors open at 10:00 and the floor empties at 22:00, so the screens come on 15 minutes early at 09:45 and go off 15 minutes after close at 22:15, with the hours and the lead time set by the venue; the slideshow duration is set to 8 seconds per image.

The rule: divide the seconds the screens are on by the length of one loop to get loops per day, then multiply loops per day by one image's duration to get that image's daily screen time.

Arithmetic:

• On window: 09:45 to 22:15 is 12 h 30 min, and 12.5 x 3600 = 45,000 seconds.
• One loop: 3 images x 8 s = 24 s.
• Loops per day: 45,000 / 24 = 1,875 loops.
• Each image: 1,875 loops x 8 s = 15,000 s per day, which is 4 h 10 min.
• Check: 3 x 4 h 10 min = 12 h 30 min, matching the on window.

Result: 1,875 loops a day, and each image gets about 29 hours of screen time per week (15,000 s x 7 = 105,000 s).

Decision: one on time and one off time per player covers all five screens, because the venue opens and closes as one building. Set 09:45 and 22:15 on every player and a normal day needs nobody at a TV. The threshold to manage is exposure per image: at 8 s each, every image takes a third of the day.

Cut one image to 4 s and the loop shortens to 20 s (8 + 8 + 4). The loops rise to 45,000 / 20 = 2,250 a day. That image's share falls to 2,250 x 4 s = 9,000 s, which is 2 h 30 min, while the other two rise to 5 h each.

One caution the setup needs: hours of near-static images are what burn a logo into an OLED panel. The three-image rotation and the scheduled dark hours are what keep these screens safe.

Power and where the player sits

Two power plans cover this kind of wall, and the plan decides how much CEC matters:

• Live outlet plus schedule. Each player stays powered after closing and sends standby over CEC at the off time. The TV gets an orderly standby, the player keeps its clock and settings, and the morning on time fires without anyone.
• Switched or timed outlet. Power to the wall drops at night and returns at opening. The TVs wake with the power, so CEC becomes optional, but every player must be built to start playback the moment power arrives, and each TV must come back on the player's input. What signage power loss recovery does for an offline display explains the difference between a player that resumes on its own and one that waits for a button press.

Then plan where each player lives. Behind a wall-mounted TV works only where the cavity is deep and an outlet is close. A small shelf under the screen or a cabinet below the counter keeps the card slot reachable, and reachability is what turns updates into the desk-plus-walk routine described above instead of a ladder job.

When to pick something else

• One TV ignores CEC commands, because some models bury the feature or label it differently: run that wall from a time-switched outlet and keep the player for playback. Test CEC on day one, TV by TV, with the remotes put away.
• You want updates with no walk at all: five players pulling from one self-hosted signage server on your local network does it with no monthly fee. The cost is your time; you install, run and patch the server, and you must confirm the players send CEC commands, because some open-source players skip that half.
• A screen dies: replace it instead of reworking the wall. We sell small all-in-one displays for this kind of spot, playing images and video from a card with no subscription, and our small retail displays are the range to check. Their HDMI port is an output, so one of them replaces a dead TV in this setup; it cannot drive the others.
• The venue grows and someone else takes over the screens: a cloud player removes the walk entirely and adds a per-screen charge that renews monthly, which is why it sits last on this list.

What to ask for

Get these answers from the specification sheet before you buy five of anything:

• HDMI output with CEC, so the player can send power-on and standby to the screen.
• A schedule with one on time and one off time per day, set on the player itself.
• Playback from the card that starts at power-up with no button press and no app to open.
• A PNG slideshow with a duration setting per image, in seconds.
• A card slot that stays reachable once the player is mounted.
• Power from a plain outlet, with no account or subscription required to play local files.
• A clear statement of what happens after a power cut: playback resumes by itself or waits.

A player that clears that list runs your five screens on hardware alone. A player that misses the first two sends you back to the remotes.

The decision for each case

Recommendation: For five screens showing the same three images on no subscription, buy one card player per screen that lists HDMI-CEC output and a daily on and off schedule, set all five players to the same two times (09:45 and 22:15 in the worked example), and update by swapping cards prepared at a desk. If one TV refuses the CEC commands, run that wall from a time-switched outlet and keep the player for playback.

Every other path trades one of your three limits: the timer trades the tidy CEC standby, the self-hosted server trades your time, the cloud plan trades the no-subscription rule, and a replacement all-in-one display trades the TVs you already own.

Questions