SmartMirror with 50“ Samsung 4K TV Power Consumption

[anthem212]

Hello there,

My old TV broke. It is Not really good for watching TV anymore but it would still work as a SmartMirror.
So I wanna build one out of it, this will be my second. My first is a old Tablet.

I wanna hang in on a Wall with a wooden frame and a Raspery behind it which is doing all the work. Maybe also Touchscreen and voicecommands.

But I have one question because of the Energieusage.
I want the TV something like “off” when nobody is walking in front of it or turning it on.
But when you really turn off a Tv and want to start again it is booting this todays for a while, something like 30 seconds.

I want this mirror always be ready to show something within one or two seconds when I press a button or walk in front of it. Without booting the TV every time. I also want the screen to go off after 30 seconds with no movement detection or when I press a button.
So the raspery needs to be running al the time in the background yes but how do I do that with the tv?
Is there something like a mode between off and on like a black screen or a energy saver which can be turned on and off controlled by the raspery?

I really don’t want the tv always on showing black Color and burning tons of energy.

Thank you,

Best wishes,

Anthem

[sdetweil]

@anthem212 well there are three commands to turn off the output

vcgencmd
dpms

these two turn off the HDMI port, NOT the monitor/tv

and cec-client

this turns off the monitor/tv
IF it supports the cec command(correctly)

and then you would need a people sensor,
most use use infrared, as it’s ‘easy’.

there are modules that put all this together.

search here for MMM-PIR

Now to get your speed requirements will be a little harder. I use TV’s for my two main mirror systems. 43 and 55 in.
one supports cec, the other doesn’t.
when I turn off the HDMI port on both, they put up a big NO INPUT screen , and power off after 15 minutes.
that is energy star compliant.
but you can’t turn them on via software

if it supports cec, then maybe you can turn off/on via software. mine is inconsistent. always can turn on, but not off
on is the same as pushing the button, takes 15 seconds, displays the product logo and all that.

I gave up, and just hide the mm content and leave the TV’s on. the one in the hall I call the nightlight!

I also use a webcam for motion detection, instead of pir, cause that’s what I had at the time

as yours is a 4k tv, I’m guessing it supports cec

install the cec-utils package on pi
sudo apt install cec-utils

this also only works on my pi 4. not pi3.