Ambient light sensor for automatic backlight adjustment?

[fahrstuhl]

Hi,

Will the Pyra have an ambient light sensor for automatic backlight control? I hadn't used my Pandora for a while and when I turned it on the other day, I noticed how much it bugs me having to control the backlight manually.

(Btw.: Couldn't you solder a photodiode to one of the empty LED pads under the lightpipes and set the connected GPIO to "input" instead of "output"? Maybe you could even set one of the GPIO on one of the existing LEDs to "input" and use the LED as the sensor (Which works with some, if not all LEDs))

 

[LEOXD]

Will the Pyra have an ambient light sensor for automatic backlight control?

This is currently not planned. But since the LEDs will be fully customizable, you can probably hack it in. 

 

[Binky]

This does sound like a good idea, especially as light sensors aren't very big or expensive.

The best place for it might be the area between the nubs, since that's least likely to be obscured by your fingers, and the sensor could be on the main PCB, using the keymat as a light pipe

 

[EvilDragon]

On the main PCB won't help much. If you enable keyboard backlighting, it will constantly glow into the photoresistor

I personally don't like automatic backlight. I hate it when my smartphone changes the brightness all the time.

Hmm, how often does your environmental light change while you're gaming?

Mine usually doesn't

 

[slaeshjag]

For me, ambient light changes around 5 times a day. I wouldn't mind automatic backlight adjustment as an optional feature.

 

[fahrstuhl]

Not while I'm gaming but while I'm on the move. Some trains in Berlin switch between above and below the ground a lot.

Edit: When I'm outside, gaming on my Pyra and it's a partly cloudy day?

 

[matzesu]

As im apple to write blind; even on the Pandora Keyboard: , for me the Keyboard Backlight only whill be a "Show Feature" , nice to impress other peaple, but soon to disaple to save Batterie ..

By the Way: is there a tough yet how many time the Keyboard Backlight and the Luminatet Logo on the Lid will shorten the battery Live ??

If i can play Mario Land twice the Time just because i disabled the Light, mybe i would do this..

 

[fahrstuhl]

As im apple to write blind; even on the Pandora Keyboard: , for me the Keyboard Backlight only whill be a "Show Feature" , nice to impress other peaple, but soon to disaple to save Batterie ..

I actually meant the LCD backlight but dimming the display AND lighting up the keyboard in low light would be a nice touch, now that I think about it…

 

[klapse]

Backlight control is hard to do in a natural way that isn't bothersome. I agree with EvilD that it isn't worth trying to put in.

 

[urjaman]

I'd be interested in the ability to experiment with automatic backlighting. Its not like you're forced to use it.

It is(/was... my pandora now is backlight impaired it seems) a pita on the pandora to adjust it n times a day when i used to take it everywhere with me - up to the point that i added a hot"key" (icon) on the taskbar to flip between a dark and light theme and min/max brightness...

I see two sides to this:

+ if we put an LDR in every pyra, it would be more of a motivator to produce good automatic backlighting code

* because you can share it

* because you dont need to hack the hw to code this stuff

- if we put an LDR in every pyra and dont use it (or 99% of Pyra's dont use it), i can see that it would be a bit of a waste of money.

 

[Hồng Thất Công]

What's all this fuss about?  Fn+I and Fn+U currently on Pandora seem to work perfectly for me

I would rather save that precious board space for something else more important.

 

[urjaman]

^ I'll just ignore the ignorants. Actually i didnt.

And seeing that the proper place for this would be in the lid - in a corner as far from the lcd as possible, and it would essentially entail somebody installing each one... I'm thinking this wont happen by default.

But I'll describe the circuit needed on the mainboard if you want to give a pad (actually 2) for this in similar fashion to how pandora has the KB BL pads.
2 pads:
- Positive stable voltage between 2.4V and 5.5V.
- An analog input with pads for a pull-down resistor and a small (1u) capacitor, with measurement range to atleast 2.3V.
 
This could also be used as a generic analog input (without populating the resistor and cap) for whatever other hack the user wants to add

 

[comradekingu]

I prefer manual button or slider control. Even for screen rotation and especially flash/photolight.

If the battery is big enough im not trying to save battery on screen. Thats how i like it.

Full blast always is the better option versus extra weight on battery. If the screen has individual lightsources then thats good.

Dynamic backlighting based on display content is the _worst_.

The car analogy would be combustion engine automatic gearing on cruise control. It can never be good becase the car doesnt know whats ahead, its just guesswork.

If it tries to speed up because it goes into hillclimb mode and ends up jumping over a hilltop as a result you remember it and become forever annoyed, even though it may mostly work.

A light sensor can be a cool idea for games, maybe it can tell by colour temperature and amount if its daylight or not. I suppose time of day and location would do that, but it could be cool to use for some things. I got a lightmap thing on my android that i think makes a map of how bright a city is at a given time.

TL;DR Almost good automatic is way worse than all manual.

 

[levi]

We could emulate that Gameboy game that you needed to take out into the sun every so often to make it work properly.  But then it we care about emulating weird old games I'd consider it far more important to have waggle and rumble built in so I could emulate Warioware Twisted properly.

 

[urjaman]

comradekingu:

Hehe, you think it's about the battery. No, its about not blasting your eyes out. And no, I'm not talking about screen content based backlighting, thats kinda silly to me.

TBH, maybe I am oversensitive to devices blasting my eyes out because i know it can be done better.

 

[Fworg64]

Ideally I'd want a physical slider, but it is probably too late in the game for that.

Function keys work fine for me provided I can remember what they are easily. Shoulder buttons might be a good one for this if brightness constantly needs adjusted.

Otherwise I have yet to see good working autoadjust, for me it always turns into some odd periodic function for my screen and it constantly occilates between the dark side and the light side of the force spectrum.

 

[_wb_]

I personally prefer manual brightness setting most of the time, but in some cases (train on a sunny day with some tunnels) it is nice to have automatic brightness control. I personally don't like it if it constantly changes the brightness slightly, I prefer it if it just has two modes (full brightness and close to minimum brightness) and toggles between those two only if there is a big enough difference in ambient light. For finetuning manual control is best. Anyway, we can make our own rules for how the automatic control works, it should be easy enough: it suffices to keep track of some running averages of the raw sensor data over some different time windows (e.g. 1s, 2s, 5s, 10s, 1m), normalized to some intuitive scale (e.g. 0=total darkness, 100=direct sun), with rules like "if (avg_5s > 70) set_backlight(MAX)", and then you can tweak those rules yourself. Or of course just disable the whole thing.

If the sensor is cheap and there is a good spot to put it (back of the lid maybe?), then why not put it in? You never know what people will do with it. It doesn't have to be used just for brightness control -- maybe someone has a greenhouse with plants, and uses the temperature sensor and light sensor with Pyra System Info to plot nice graphs

 

[thatgui]

I personally don't like automatic backlight. I hate it when my smartphone changes the brightness all the time.

I guess the threadstarters orginal intent was to have it as an option.

Hmm, how often does your environmental light change while you're gaming?

Mine usually doesn't

As I am a commuter using public transport on a daily basis, environmental light changes happen a lot, so I would definately be interested.

Full blast always is the better option versus extra weight on battery. If the screen has individual lightsources then thats good.

Dynamic backlighting based on display content is the _worst_.

No its not, especially in situations were the envronmental light is only dim, is counterproductive to have the brightness set to "full blast".

 

[Hồng Thất Công]

Or put a wheel like the volume wheel for control brightness/contrast.  I like the volume wheel a lot

 

[Yoyobuae]

/joking/

With a front facing camera the device could capture and measure the amount of pupil dilation of the user's eyes and adjust the backlight accordingly. Why use a light sensor when you can read the same info from the user's own eyes?

/joking/