Is it possible to develop a feature that allows for direct disconnection of external displays?Sleep Off

[kautzerdakotasfsd-dotcom]

Is it possible to develop a feature that allows for direct disconnection of external displays?Sleep Off

[didriksg]

It's already possible to disconnect a display when you have more than one display connected. This is a limitation I've set up so that you always have at least one screen active

[kautzerdakotasfsd-dotcom]

Previously, I used the DisplayBuddy software to achieve this functionality using the DDC/CI protocol. However, after updating macOS to version 27, the software no longer worked. I am now searching for alternative software that can provide this functionality. I would appreciate it if you could add this feature to your software. Thank you.

[didriksg]

I built crispctl display poweroff and tried it on my own monitor tonight, and I've pulled it from 1.6.0 before it ships. The write works: the monitor switches itself off. But it keeps its DisplayPort link up while it is off, so macOS keeps it in the display arrangement, windows still land on it, and Crisp keeps showing it as a live display with a working brightness slider. Nothing on the Mac can tell that it is off, and only the monitor's own button brings it back. A command that leaves Crisp showing a display that isn't there is worse than no command.

On your desk it would be worse still. With the external as your only display, macOS would think it is still on, and the disconnect that would release the arrangement is refused for the last display.

What works today is display sleep on a key (pmset displaysleepnow in a Shortcut), which most monitors follow with their own standby and auto-off timer. One thing you can tell me that I can't measure here: if DisplayBuddy's DDC path stopped on macOS 27, the one Crisp uses may have too. Does Crisp's brightness slider move your monitor on 27? That says whether DDC is alive there at all.

I'll come back to this once I have a design where Crisp actually knows the display is off.

[kautzerdakotasfsd-dotcom]

crispctl displays power off
{"ok":false, "error": "unknown command 'display poweroff'; use 'crispctl display' for display commands"} – This is the output from the terminal, and it's not helpful.

[didriksg]

That command isn't in 1.6.0. I pulled it the day before the release, for the reason in my comment just above: the monitor does switch itself off, but it keeps its DisplayPort link up, so macOS and Crisp both still see a live display with a working brightness slider. On a headless Mac with one external, that would leave you with a dark screen the Mac thinks is on, and the disconnect that would release it is refused because it's your only display.

For now, display sleep on a key is the closest thing that works. Make a Shortcut that runs pmset displaysleepnow and bind it to whatever you like. If your monitor has an auto-off timer in its power or eco menu, turn that on too and it'll switch off entirely a few minutes after the signal drops.

One thing would really help me here. You're on macOS 27, and you said DisplayBuddy's DDC stopped working for you there. Crisp talks to monitors over the same path, so I'd like to know whether it still works on 27 at all. Could you open Crisp and drag the brightness slider for your monitor, and tell me whether the monitor actually gets brighter or darker? If it doesn't, DDC is broken on 27 and a power command wouldn't work for you either, which is worth knowing before I build one.

[kautzerdakotasfsd-dotcom]

In macOS 27, version 1.6 of Crisp can control the brightness of external displays. Currently, this software is more effective than DisplayBuddy. After macOS 27, DisplayBuddy is no longer able to adjust brightness or power off external displays.

[didriksg]

I built crispctl display poweroff and tried it on my own monitor, but I've pulled it from it ships. The write works: the monitor switches itself off. But it keeps its DisplayPort link up while it is off, so macOS keeps it in the display arrangement, windows still land on it, and Crisp keeps showing it as a live display with a working brightness slider. Nothing on the Mac can tell that it is off, and only the monitor's own button brings it back. A command that leaves Crisp showing a display that isn't there is worse than no command.

I'll come back to this once I have a design where Crisp actually knows the display is off.