Author Topic: automatic brightness adjusting of screen and/or indicators  (Read 1387 times)

specing

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automatic brightness adjusting of screen and/or indicators
« on: February 10, 2015, 12:46:11 PM »
via light sensor, possible locations:
    - indicator board (issues? LEDs might interfere)
    - camera/mic/thinlight board on top of screen
    - near the front of base unit?
    - somewhere else?

via camera? (Probably a no-go, but keeping it here for reference)
    - Take a picture and derive amount of light shining directly onto the screen.
    - the bad: requires a coprocessor that:
        - has the required hardware interface http://mipi.org/specifications/camera-interface
        - is fast enough to pass-through video (DMA?)
        - is fast enough to run some algo on the captured image.

Offloaded to EC or some other mcu that controls the backlight.
« Last Edit: February 10, 2015, 12:51:01 PM by specing »

Adarion

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Re: automatic brightness adjusting of screen and/or indicators
« Reply #1 on: February 17, 2015, 05:19:24 AM »
Camera = no go. Privacy issue. Though I admit that a camera would already contain a sensor by itself.
A shut-able cam and mic would be neat, by the way.

I do have an Eizo IPS screen as of late and it has this ambient light function. I do see benefits but also drawbacks. So it has a motion (?) sensor, something that is supposed to detect "presence". It switches the screen off once it does not detect someone for ... I think it was adjustable... like 3 minutes. But I normally do this setting in KDE or xorg.conf by just blanking / DPMSing the screen after 3 minutes of inactivity. And some video players will override this, luckily. ;)
The other thing is ambient light. It works so-so. Sometimes it is too dark for me just because my head is blocking the lamp from the ceiling that is behind me. So the monitor thinks it is dark and it doesn't need to glow so much and reduces brightness to a point that is already uncomfortable.
Some other times it works nicely and doesn't blind you when the room is darker.

If the feature is not too expensive and can be switched off / overridden it should be fine to implement.

specing

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Re: automatic brightness adjusting of screen and/or indicators
« Reply #2 on: February 17, 2015, 03:44:42 PM »
> Camera = no go. Privacy issue. Though I admit that a camera would already contain a sensor by itself.

When the camera becomes a privacy issue you already lost control over you OS
and as such have bigger problems than someone seeing your face.

> A shut-able cam and mic would be neat, by the way.

But yeah, a hardware (no software control) "camera on" and a "mic on" LED is a good idea.
(something you could solder off if it bothers you)

> I do have an Eizo IPS screen as of late and it has this ambient light function. I do see benefits but also drawbacks. So it has a motion (?) sensor, something that is supposed to detect "presence". It switches the screen off once it does not detect someone for ... I think it was adjustable... like 3 minutes. But I normally do this setting in KDE or xorg.conf by just blanking / DPMSing the screen after 3 minutes of inactivity. And some video players will override this, luckily. ;)

the entire code will be open source and you will probably be able to
reprogram it on the fly, without shutting down.

> The other thing is ambient light. It works so-so. Sometimes it is too dark for me just because my head is blocking the lamp from the ceiling that is behind me. So the monitor thinks it is dark and it doesn't need to glow so much and reduces brightness to a point that is already uncomfortable.
Some other times it works nicely and doesn't blind you when the room is darker.

This is exactly where camera-based light sensing would come in handy, as the
software would know where the bright spots are and whether they are blocked.

> If the feature is not too expensive and can be switched off / overridden it should be fine to implement.

Im sure the light sensors themselves are cheap