The one thing that still bugs me when using my LG OLED TV as a computer monitor is that it doesn’t
have an auto sleep feature like a traditional monitor to save power and prevent burn in.
Sure, you can just use a screensaver, use the built screen off feature,
or use a 3rd party application like LG companion all of which
I have used and work well, but aren’t perfect for my needs.
But what if I could make the OLED TV smart enough to know when I’m actually at the screen
and then automatically turn off when I’m away. And then back on again, completely seamlessly.
So that’s what I did, I programmed an ESP32 together with a motion sensor to
control my OLED TV. It’s incredibly responsive turning on the screen the moment I arrive,
and back off again within seconds, saving power and protecting the screen. It’s
completely agnostic of the device I’m using, so it works whether I’m taking a lunch break
from the work laptop, or I need to take a bathroom break while playing on the PS5.
Hi I’m David and this is my Burn In Prevention prototype for my LG OLED TV
When I first started designing this prototype, there were two fundamental
challenges I needed to solve. One, how do I quickly turn off the OLED screen,
and two, how do I sense if I’m actually at or away from the TV?
Turning off the OLED TV is the easy part, as there are multiple ways this can be done. On a computer
the easiest way is just using a completely black screensaver that on an OLED panel, basically
turns off all the pixels. But a screensaver is a device specific implementation and won’t
work on something like my PS5. You can obviously just turn off the TV every time you walk away,
but full power off and on functionality is slow, taking up to 3 or 4 seconds to
fully wake up sometimes. Thankfully these LG OLED TVs have a built in Screen Off function
that you can access in the menu. But this can also be quickly activated via commands sent
to the TV with their app, voice controls or Home Assistant, which is the method I chose.
The other problem, Sensing if I’m still at the computer is more difficult to solve but
again there are a variety of different ways to approach this. The most advanced
way would to be to use a camera and leverage some AI algorithm to detect if I’m in the frame
but frankly that’s overly complex for what we need here, also being a waste of electricity,
computation performance, and frankly I don’t like the idea of having a camera constantly on me.
PIR sensors or Passive Infrared are the next obvious solution here being universally used
in those automatic light sensors, which work by sensing the infrared light our
bodies give off as we pass by the sensor. They’re cheap, quick, and power efficient.
Which is how I started my initial prototyping using a AM312 PIR sensor
and while it works well detecting when I approach the screen, the moment I stop moving,
it stops detecting me. Sitting in front of the computer is not enough movement to keep these
PIR sensors active. Also with this AM312, I was getting some random false positives
probably from electrical interference or my lights. So I shelved that sensor for now.
So instead, I looked at mmWave sensors. These sensors send electromagnetic waves out and
read the reflected signals to determine an object’s position and motion. The one I’m
using is this cheap LD2410 sensor, and it uses an extremely high 24GHz frequency that allows
it to be sensitive enough to the minor movements of our bodies, even when just sitting still. Out
of the box it works really well, maybe a little too sensitive detecting me even before I enter
the room. But with mmWave sensors you’re able to configure both the sensitivity and the distance
it will detect. I configured mine to only detect me within 1.6 meters, so even if I’m
in the room doing something else, it won’t trigger until I move within that boundary.
So with those two solutions in place, I programmed some logic into an ESP32
with a built in display, and this is my resulting implementation.
I have the device plugged into the USB plug on the OLED TV for power,
so it only runs when the TV is actually powered on.
Upon turning on the TV it boots up and if it detects a person, there’s nothing it needs to do,
so after a couple seconds it goes into a screensaver, in my case just a basic clock.
The moment I walk away, the LCD prompts saying it doesn’t detect any motion and
counts down for a couple seconds before turning off the OLED screen.
And then a new 1 hour countdown starts, before it will completely shut off the OLED TV.
If I return to the desk before then it automatically wakes the screen,
and if leave again all the countdown are reset and the process starts again.
It’s important that I still allow the TV to fully shut down when I’m done for the day,
whether automatically or manually, to let the TV run its automatic pixel refresher,
and it’s easy to tell that it’s fully powered off because the device will also show a blank screen.
And when I start the next day,
I know to just power it on with my keypad to start the process all over again.
I’ll be honest, when I first started this project, it was more a joke than a real solution that
thought I’d use. But it’s not a perfect solution. So let’s talk about some of the limitations.
The mmWave sensor I’m using, might not work for all room, since if you have a pet, a fan,
or anything that moves nearby, and it can even detect objects through thinner walls,
may falsely trigger this device. So the positioning of the sensor is really important,
keeping in mind the sensor’s range and direction.
This solution is also highly dependent on my wireless network and the Home Assistant
server to send those commands to the LG TV, And if any of that goes down,
this stops working. So I would like to bypass all that in the future.
But for now, I still have some redundancy like the screensaver and
screen off function on my computer, and the power off feature on the LG TV when
there’s no signal. And also, I just make sure it’s turned off at the end of day.
Other solutions I might try in the future are Thermal Cameras, a pressure sensor on my Chair,
or a laser break at my Door in place of the mmwave sensor to detect my presence.
But that for a future video, hope you guys enjoyed this one. You know
what to do. And I’ll see you in the next video.