DIY: upgrading your old Kobo to be comfort-lit

[Korn on the Kobo]

Here’s a quick hack I did that saved me $100+. Over the last year I became a stickler for anything that can diminish my melatonin level, so I eliminated my exposure of blue light after sunset to virtually zero. One casualty of that was my trusty old Kobo — hardly used — that I never got to enjoy, because (even at 1% brightness) it's a major eyesore that keeps me up for hours squinting in the dark, instead of dozing me off which is what reading in bed is supposed to do. I was about to toss it out and upgrade to a Clara HD/Forma… until I reasoned I could just retrofit it with better lighting functionality. So here it is… how to hack up Korn on the Kobo’s "Poor Man’s ComfortLight Pro":

1. Buy a clip-on LED book reading light accessory. Usually $10 but if you search well enough you can score one for $1 (usually as samples for corporate swag/merch suppliers). Extra brownie plus points if it’s RED! If not, you can get artsy-craftsy and convert it easily by drawing over the lamp layer with a red marker/sharpie, let it dry, apply again, then scotchtape over to protect it. Clip onto your old Kobo and position the lamphead over the screen.

2. Connect the Kobo (in my case a 1st-gen Aura) to your computer, navigate its drive to KoboeReader/. kobo/ Kobo and open the file "Kobo eReader. conf” with Notepad (Windows) or TextEdit (Mac). Show hidden files/folders in your file manager if you don’t see them. Change the setting “FrontLightLevel=(number)” to =0, save (save anyway if version lock errors), eject/disconnect, unplug

3. Power off and on in the dark to test that the screen doesn’t emit any light anymore. Turn on red led whenever you use it.

4. Read “The Primal Scream” under the covers and sleep like a baby cuddling your ancient Kobo in your arms, relishing in the fact that you have gamed and triumphed over the Lords of Planned Obsolescence.

Why this is better than white-on-black Nightmode hacks:
- Improved battery-life*
- Prolonged lifespan of screen*
- Less EM radiation*
- Easier on the eyes
- Red light promotes optimal biorhythms
* EPDs (electrophoretic displays = eink screens) work opposite of LCDs in that they consume energy to display black. This DIY jig saves them from struggling to keep the bubbles of almost the entire display charged to keep the pigment visible on top while you mindlessly tap Klondike cards.

[DNSB]

Originally Posted by Korn on the Kobo

* EPDs (electrophoretic displays = eink screens) work opposite of LCDs in that they consume energy to display black. This DIY jig saves them from struggling to keep the bubbles of almost the entire display charged to keep the pigment visible on top while you mindlessly tap Klondike cards.

It takes the same energy to change a pixel from white to black as it does to change from black to white. And once a pixel is set, it takes no energy to maintain that state. That is the reason why eInk displays take less energy. When I power off my Kobo, the image on the screen will remain for months.

One other item is that the capsules contain both white and black pigment unless you have a truly antique eInk display.

[davidfor]

Originally Posted by Korn on the Kobo

2. Connect the Kobo (in my case a 1st-gen Aura) to your computer, navigate its drive to KoboeReader/. kobo/ Kobo and open the file "Kobo eReader. conf” with Notepad (Windows) or TextEdit (Mac). Show hidden files/folders in your file manager if you don’t see them. Change the setting “FrontLightLevel=(number)” to =0, save (save anyway if version lock errors), eject/disconnect, unplug

Or, you could just press the button on the top of the device and turn the light off. I mean, that's what it is for. Unlike some other devices, for Kobo, off is actually off.

And for devices without a separate button for the light, just use the slider, or the side swipe to turn it off.

[Korn on the Kobo]

Originally Posted by davidfor

Or, you could just press the button on the top of the device and turn the light off. I mean, that's what it is for. Unlike some other devices, for Kobo, off is actually off.

And for devices without a separate button for the light, just use the slider, or the side swipe to turn it off.

Had tried that with my 1st gen Aura and it just put my Kobo to sleep, so I assumed it’s that way by design, for everybody. It’s more likely a different tweak under Settings than it is a bug or missing feature but… now that I’m happily red-lit, you could file this under ‘Ways to Scratch your Left Ear with your Right Hand!’

[Korn on the Kobo]

Originally Posted by DNSB

It takes the same energy to change a pixel from white to black as it does to change from black to white. And once a pixel is set, it takes no energy to maintain that state. That is the reason why eInk displays take less energy. When I power off my Kobo, the image on the screen will remain for months.

One other item is that the capsules contain both white and black pigment unless you have a truly antique eInk display.

You’re right! Nonetheless, still more work to float more 100% Black cells up screen-estate-wise as nightmode does compared to black-text-only over clear-state, for a 2013 Carta-based reader like the original Aura.

[DNSB]

Originally Posted by Korn on the Kobo

You’re right! Nonetheless, still more work to float more 100% Black cells up screen-estate-wise as nightmode does compared to black-text-only over clear-state, for a 2013 Carta-based reader like the original Aura.

Ummm... takes exactly the same amount of work to float the black pigment or the white pigment in a cell to the top. There is no clear state. Black, white and 14 shades of gray. Someone might want to argue that after a ghost clear, it takes more power to write the first white text on black background page but again, a trivial amount compared to the white/black/white flash itself. And note the original Aura was the first Kobo ereader to use Regal technology to reduce ghosting.

[Korn on the Kobo]

Originally Posted by DNSB

Ummm... takes exactly the same amount of work to float the black pigment or the white pigment in a cell to the top. There is no clear state. Black, white and 14 shades of gray. Someone might want to argue that after a ghost clear, it takes more power to write the first white text on black background page but again, a trivial amount compared to the white/black/white flash itself. And note the original Aura was the first Kobo ereader to use Regal technology to reduce ghosting.

That’s tremendously insightful. From an electrical engineering perspective it sounds counterintuitive… so much more logical that Not to electrically charge a pigment cell for it to remain at the bottom layer is 100% more efficient powerwise than to charge the upper layer for it to float upwards… else the device would always be consuming power to keep the lower pigments on the lower layer which we know eink doesn’t. And from a chemical/materials science one that the white dye would make the screen look much whiter on the spectrum. Big thanks.

[Quoth]

Originally Posted by DNSB

It takes the same energy to change a pixel from white to black as it does to change from black to white. And once a pixel is set, it takes no energy to maintain that state. That is the reason why eInk displays take less energy.

One other item is that the capsules contain both white and black pigment unless you have a truly antique eInk display.

I think the first displays had a milky liquid and only black capsules, so white was a little greyer and black not quite as dark.

Indeed the image may stay indefinitely if the screen is unplugged or the battery is dead. Some readers use the last gasp of the battery to put a warning message about charging otherwise you might be baffled.

[JSWolf]

From the thread titles, I was thinking this was changing the LEDs and creating a software mod to allow the color changing LEDs to work as such.

[Korn on the Kobo]

Originally Posted by JSWolf

From the thread titles, I was thinking this was changing the LEDs and creating a software mod to allow the color changing LEDs to work as such.

Sorry for the clickbait! But hey, the workaround works like a charm.

I had considered internally replacing the blue diodes or lighting wafer and re-soldering (or just painting them red), but didn’t want to risk damaging it my Aura was built to be solid form factor without screws to open; they’re really not so repairable/built for maintainability-- rather to dispose/replace. If someone here knows how to pry them open without breaking the screen or activating a software warranty-voided lock, would love to hear. In theory you could strip the external clip-on red LED attachment, glue it pointing down onto the screen, hide it inside a nicer-looking sleep cover or custom printed 3D-printed shell/case/frame/mesh. Just keep its button to push exposed.

[DNSB]

Originally Posted by Korn on the Kobo

That’s tremendously insightful. From an electrical engineering perspective it sounds counterintuitive… so much more logical that Not to electrically charge a pigment cell for it to remain at the bottom layer is 100% more efficient powerwise than to charge the upper layer for it to float upwards… else the device would always be consuming power to keep the lower pigments on the lower layer which we know eink doesn’t. And from a chemical/materials science one that the white dye would make the screen look much whiter on the spectrum. Big thanks.

The word you are searching for is inertia. Until the display is acted upon by an external force, the pigments will stay where they are so no power needed to maintain the display.