Glo Controlling the Glo's Frontlight

[Frenchdummy]

Originally Posted by KevinShort

That's something I'd love to try to do if I can find the time.

Good idea ! I also feel the brightness too hard. But I don't want to invert the screen "colors", I'm wondering about the battery.
I've to congratulate all of you for this thread and others.
(For French users there is also a good post with several tips) there

Sorry I leave, I'm not a dev

[ewphoenix123]

Just tested the this with 2.5, the lowest light level on my device is now identical to the setting the low light plugin forces.

[akorx]

Originally Posted by KevinShort

...
I got that from the freescale eink documentation. It's usually used to "flash" the screen to remove ghosting. What my "inverted mode" package does is call that eink inverted update code every two tenths of a second, giving you an almost constant white on black display.

Hi Kevin,

Does it mean that there is a difference for the battery autonomy when we use "night mode" contrary to "day mode" ? when the page is loaded with "night mode" method, the screen continues to be drawn?

And if there is really a difference for battery, why must you used this "update every 2 tenths of a second" ??? eink doesn't stay "fixed"? there is some ghosting ???

Sry for may bad english... i'm french.

[KevinShort]

The reason my night mode hack updates the screen so often is because I don't know when the user opens a menu, turns a page, etc., so I just update the screen every two tenths of a second. The proper way of making a night mode would be to somehow detect when the display changes, and only then invert the screen.

[akorx]

ok i understand, thx for the explications...

But why there is a difference with day mode? in day mode we don't know when the user will tocuh the screen too and we don't redraw the screen each tenths.

I think you must talk with the developpers of 2.5.0 firwmare, because your knowledge should help them to develop a good firmware with a lot of functions for ours kobo.

[Lucas Malor]

I think that if the page is refreshed, it returns to be normal, not inverted.

(ps: explanation - developer. Don't worry, my english is not so better, I use Firefox with spell-checking ^^)

[yoq]

I found a way to modify the update-request as it happens, so no resources are wasted. As of now it requires an restart of nickel to activate inversion. I'll post it the next days as soon as I can change the mode on-the-fly from within nickel.

Technical info: interposing ioctl() with LD_PRELOAD

[Lucas Malor]

Hey, good work

Do you know if there's a way to suppress the refreshing and add an invert after the page load? I mean, normally the screen is inverted before the page is displayed. With this hack we add another inversion after. It is a simple way to get the things working, but it will be less resource consuming if the page will be displayed, and inverted after it.

[Frenchdummy]

Originally Posted by ewphoenix123

Just tested the this with 2.5, the lowest light level on my device is now identical to the setting the low light plugin forces.

Where is the plugin you speak about ?
Which means ? Could you be more explicit, please. By the way I'm not/never Wifi connected. Then I don't have the 2.5 updt. I will wait calibre update.

[tapioco2000]

thanks Kevin, it works like a charm!

[Lucas Malor]

@Frenchdummy: you can find the "plugin" at the first post of this thread.

About firmware, for what I know Calibre doesn't update device firmwares. Furthermore I personally decided to not update to 2.5.0 or 2.5.1 firmware, since they have minor improvements but a huge bug with pdf refreshing.

[yoq]

Originally Posted by Lucas Malor

Hey, good work

Do you know if there's a way to suppress the refreshing and add an invert after the page load? I mean, normally the screen is inverted before the page is displayed. With this hack we add another inversion after. It is a simple way to get the things working, but it will be less resource consuming if the page will be displayed, and inverted after it.

I intercept the update-screen-command from nickel to the display driver and flip the flag that determines whether the screen is drawn negative. So when nickel does a page refresh it just sets this flag and issues the command. All my hack does is invert this flag, so there shouldn't be any unecessary drawing on the screen.

[KevinShort]

Originally Posted by akorx

But why there is a difference with day mode? in day mode we don't know when the user will tocuh the screen too and we don't redraw the screen each tenths.

In day mode my hack just stops running, so the display goes back to normal.

Originally Posted by akorx

I think you must talk with the developpers of 2.5.0 firwmare, because your knowledge should help them to develop a good firmware with a lot of functions for ours kobo.

The official Kobo devs are supposed to be busy fixing bugs. They shouldn't have time to add new features until they squash the well-documented bugs mentioned around the forums.

Originally Posted by yoq

I found a way to modify the update-request as it happens, so no resources are wasted. As of now it requires an restart of nickel to activate inversion. I'll post it the next days as soon as I can change the mode on-the-fly from within nickel.

Technical info: interposing ioctl() with LD_PRELOAD

Awesome! I knew there was a way to intercept the ioctls, I just didn't know exactly how and hadn't had enough time to look into it fully. I look forward to seeing it!

[akorx]

Kevinshirt, Yok : now exchange about your solution and ideas and update your plugin... on my side I take care to put the beer in the fridge ! if you want i'll send your Champagne and wine from France !

Lucas Malor : thx for your help about my spelling ! if nobody corrects me, i will never progress !

[yoq]

Sorry to have kept you waiting, but i stumbled across an annoying bug in the driver (details in the source code), and it took me some time to understand whats going on.

Anyway, it works now and it should be easier on your eyes and on the Kobo's battery than the old hack. Props to Kevin for the initial research!

Installation:

• Copy screenInv.so and nightmode.sh to your .kobo folder
• Change the following line in your rcS (the one in the zip is just an example), from:
  

  /usr/local/Kobo/nickel -qws &

  to:
  

  LD_PRELOAD=/mnt/onboard/.kobo/screenInv.so /usr/local/Kobo/nickel -qws &

• Add this line to your kobotweaks.ini
  

  Toggle Night Mode=tweaks.executeSystemCmd(\"/mnt/onboard/.kobo/nightmode.sh\")

• Reboot and it should work

This is licensed under the GPL and was tested on a Kobo Glo with FW 2.5.1.

A word of caution:
This hack has the potential to freeze nickel, therefore, if something goes wrong badly you won't be able to activate WiFi. So I recommend you to activate Network over USB as a backup plan: https://wiki.mobileread.com/wiki/Kobo...lnet.2FFTP_USB