Sansa e200 - wheel light fade in/out, also display fade in/out

[casainho]

Hello!!

Well, I would like to see wheel light fade in/fade out, also fade in/out in display. I think that should not be difficult to implement, maybe PWM, changing duty-cycle.

Also the quantity of light in wheel, like the light in display that is already implemented.


I got my new Sansa e200 yesterday, bought it because I wanted RockBox, FLAC and OGG :-) - I am a supporter of FreeSoftware ;-) - Thank you all for this GREAT WORK!!

I don't listen well from my ears, so using balanced options in sound to put more volume in left channel, to my left ear was great, a feature that I didn't have in my old player ;-)

Thank you. JP Casainho from Portugal - http://www.Casainho.net

[GodEater]

Well, I would like to see wheel light fade in/fade out, also fade in/out in display. I think that should not be difficult to implement, maybe PWM, changing duty-cycle.

You should submit this as a feature request then (see the link on the left of the page).

I got my new Sansa e200 yesterday, bought it because I wanted RockBox, FLAC and OGG :-) - I am a supporter of FreeSoftware ;-) - Thank you all for this GREAT WORK!!

Welcome to the family

[JdGordon]

You should submit this as a feature request then (see the link on the left of the page).

no, you shouldnt.
the light is either on or off... adding the logic in to do the dimming in software is not going to happen.

[casainho]

jdgordon, can you please tell me why the light in the wheel can not be dimming?? It's hardware limited, software limited?

What about a plugin for dimming accordingly the music? maybe beats per minute?   - I am dreaming? Some one already made this request:
http://www.rockbox.org/tracker/task/7089?histring=wheel

And what about display fade in/out?

[JdGordon]

I said...
the light is either on or off.. there is no hardware dimming possible..
it can be done in software but its not going to be added because im all honesty.. its stupid.

[casainho]

Ok, so just software dimming is possible.

In my opinion, thats not stupid idea, Its a question of harmony, as the natural light of sun reach us, fading in on morning and out on evening. Rapid transitions are not natural to humans and I believe that behavior passes some stress to us, for example in illumination on our houses (at least in mine, here in Portugal).

Okok, but I understand that should be more important, urgent things to implement on RockBox.

Thank you.

[AlexP]

So non dimming wheel lights stress you?

Blimey.

I think JDGordons point here (I apologise if I am wrong) is that this is quite a bit of code that would bloat the core taking up buffer, increase complexity, add more options etc. for almost zero benefit except it might look a bit pretty to some people.

[GodEater]

And increase binary size significantly too - also not popular with the devs...

[AlexP]

And increase binary size significantly too - also not popular with the devs...

I said that!  (Sort of - I meant it anyway

that would bloat the core taking up buffer

[GodEater]

What do you want me to do ? Delete my post ?

[krazykit]

Its a question of harmony, as the natural light of sun reach us, fading in on morning and out on evening. Rapid transitions are not natural to humans and I believe that behavior passes some stress to us, for example in illumination on our houses (at least in mine, here in Portugal).

To avoid this rapid transition, you could just keep the wheel light off, of course.

[scharkalvin]

Well there was a patch to adjust the back light intensity of ipods and this had to be done in software (this is a pulse width modulation of the power to the back light).
So it's something that can be done.  I'm not sure how the ipod hardware controls the back light, there may be less software overhead involved in this case.

Anyway, there will always be un-supported patches and builds for the kind of off the wall stuff that some people just can't live without,  and the rest of us don't want to waste cpu cycles on.

[casainho]

To avoid this rapid transition, you could just keep the wheel light off, of course.

Thats what I do now, because I have low bright selected for display and the wheel light is to strong and does not let me see in a good way the display. It would be nice to have low bright, less than display, in the wheel light.

Well there was a patch to adjust the back light intensity of ipods and this had to be done in software (this is a pulse width modulation of the power to the back light).
So it's something that can be done.  I'm not sure how the ipod hardware controls the back light, there may be less software overhead involved in this case.

Anyway, there will always be un-supported patches and builds for the kind of off the wall stuff that some people just can't live without,  and the rest of us don't want to waste cpu cycles on.

Yes, pulse width modulation PWM as I suspected To not see flicker, at least 5 kHz of PWM, to get 1% increments o duty-cylce at 50 Hz, so, at 50Hz no flicker to human eyes :-)

IDEA to implement:

Lets assume that we have one variable -  Tick_5kHz_Counter, that is incremented every 5 kHz (maybe with a tick of 5 kHz) and goes from 0 -> 99 every time.

Duty_Cycle is a variable that keeps the percentage of light, from 0% till 100%. Duty_Cycle could be updated on an entry menu with name "Wheel options".

if (Tick_5kHz) {

 if (Tick_5kHz_Counter < Duty_Cycle) {

  Wheel_light_IO = ON;
  }

  else {
 
    Wheel_light_IO = OFF;
  }
 }
}

Tick_5kHz = false;


I paid one time for CPU and for memory, I pay constantly for energy on battery! I prefer CPU cycles for dimming the light than for videos. My sansa have a lot of CPU power and bytes for code, but I would prefer to saving battery, and diming light can save battery, maybe more than can spend on the cycles to do that.

[Llorean]

The PWM method of handling the iPod 5G screen brightness was actually turned down and investigation was done to find a hardware method to handle it, since evidence suggested it existed.

[JdGordon]

I paid one time for CPU and for memory, I pay constantly for energy on battery!

you know that if the light is on then more batter is being used right? so you end up using more power... especially when you want to get the cpu doing more work which does nothing more than make the display look a bit nicer....