Experimental HDMI-CEC controls turn the display on and off

If the screen is a TV, you can now switch it on or off from Anthias's Settings page. The controls are experimental, and on a Raspberry Pi 2, 3 or 4 they only work from Anthias 2026.08.1, which fixes them.

Settings has a new "Display power" section, marked Experimental, with "Turn display on" and "Turn display off" buttons. They send the command to the connected display over HDMI-CEC, and a message tells you whether the command was sent. The section only appears when the device has a CEC adapter: /dev/cec0 on a Raspberry Pi 5, x86 or arm64 board, or /dev/vchiq on the older Raspberry Pi models. On a Raspberry Pi 2, 3 or 4 the controls couldn't work in this release: System info showed "CEC error" and the buttons failed.

Whether the TV obeys is up to the TV. A command the display doesn't answer within 10 seconds comes back as an error.

Raspberry Pi 5

On a Raspberry Pi 5 the CEC device wasn't passed into the Anthias containers, so the "Display Power (CEC)" card on the System info page read "CEC error". Upgrading to Anthias 2026.05.1 passes /dev/cec0 and /dev/cec1 through, and that's also what makes the new buttons appear there. On x86 and arm64 boards the upgrade passes /dev/cec0 through when the board has one.

For developers

POST /api/v2/display/on and POST /api/v2/display/off do the same thing. They return 200 when the command was sent, 502 when the display or adapter refused it or didn't respond, and 503 when the device has no CEC adapter.