Jailbroke my Kindle to use it as an e-ink monitor | Hacker News Reader

Jailbroke my Kindle to use it as an e-ink monitor

gist.github.com

421 pointsadtac139 comments

This would be far more interesting if you shared how, and did it on a platform that wasn't meant for short form content.

Writing a quick Github gist, sorry haha, I'll post a link here in a few minutes.

Edit: https://gist.github.com/adtac/eb639d3c707b55a28f0ee9a420aa7e...

Ok, we've changed the URL above to that one from https://twitter.com/adtac_/status/1820127470613622950, which it includes.

Thanks!

dang, can we merge this thread into https://news.ycombinator.com/item?id=41155177 or vice versa?

Sure.

I did not expect your username to be dang, I thought he meant it as a figure of speech like "dang"

Dan G. IRL

Legend.

The twitter thread has the demo, which is pretty neat. Github link is lacking that (maybe the author can add the demo to that).

Here's a direct MP4:

https://video.twimg.com/amplify_video/1820127349548982272/vi...

You could probably direct link it in markdown to embed it, although i'm not sure if Twitter will serve it on a high-traffic gist like this one after a while (I imagine there's some sort of rate limit-based hotlink protection).

10 updoots for u kind sure.

Can it cause my Kindle to get bricked?

Probably. Jailbreaking is always a risk, and you should research and understand the risks before undertaking.

Interesting that you perceive hn as a platform for short form content.

They were talking about the original link to a tweet

Ah, missed that.

Twitter is where his link points...

Yeah, I figured that out about 6 hours ago: https://news.ycombinator.com/item?id=41158720

Though it did already point to the gist back then, and I am still unsure how I can tell it pointed to twitter originally.

Thanks though?

> I am still unsure how I can tell it pointed to twitter originally.

You can usually find a comment by dang saying something like "we've changed the URL from <old link>".

You said this much more constructively that I might - I really dislike when people post long form stuff on X/Twitter. For those who may not know you can reply to a tweet with “@threadreaderapp unroll” to have a reconstructed doc sent to you. The bot will reply directly to you and only you after the unrolling is complete. Hope that helps someone.

I know this one has been fixed, but I also find those an annoyance - more so because if you're not logged in on twitter, you only see the first tweet, not the thread. So rather than get irritated when I click through stories, I block the links on HN with ublock-origin rules like so:

    news.ycombinator.com##tr.athing:has(a[href^="from?site=twitter.com"])
    news.ycombinator.com##tr.athing:has(a[href^="from?site=twitter.com"])+tr
    news.ycombinator.com##tr.athing:has(a[href^="from?site=x.com"])
    news.ycombinator.com##tr.athing:has(a[href^="from?site=x.com"])+tr
    news.ycombinator.com##tr.athing:has(a[href^="from?site=medium.com"])
    news.ycombinator.com##tr.athing:has(a[href^="from?site=medium.com"])+tr

2 rules each because the replies and the story titles don't share a common parent element. eg right now I can tell from the numbers beside the stories that number 23 is missing; but otherwise HN looks the same. The same trick works for google search results; I have rules like the ones below to block less useful tutorial sites when I'm looking for python/js docs:

    google.com##div:has(>div>div>span>a[href^="https://www.w3schools"])
    google.com##div:has(>div>div>span>a[href^="https://www.geeksforgeeks"])
    google.com##div:has(>div>div>span>a[href^="https://realpython.com"])
    google.com##div:has(>div>div>span>a[href^="https://www.programiz"])
    google.com##div:has(>div>div>span>a[href^="https://www.datacamp"])

Hope this helps folk too; I'm not going to fight a battle over links to these sites (and others I've blocked), I'm just trying to improve my own experience of the site.

I do something similar with Google search results. I hide results from Pinterest, Quora, TikTok, ...

I can recommend uBlacklist for that: https://iorate.github.io/ublacklist/docs also supports other search engines

That requires you to have a twitter-account though...

I did a similar project HDMI in

https://hackaday.com/2021/01/08/old-kindle-shows-hdmi-video-...

to make an OK Monitor - https://barwap.com/projects/okmonitor/

FYI: I'd pay to cover costs if there was a just-works off-the-shelf version of this.

I don't think there's a business model there (I suspect the sales would be in the thousands or tens of thousands of dollars -- so no matter where you set your profit margin, you're not covering your time or much beyond costs), but I've sometimes seen things done like that on hobby projects just for impact.

I'd love to have a wireless eInk display for my computer, ideally from a USB-C dongle (so it gets video and power), but HDMI + USB power would be fine too.

There is: https://shop.boox.com/products/mira

You could also use any eink tablet that runs Android with a screen mirroring app.

That looks very nice.

The $1800 version is exactly what I'd love to have as an extra monitor on my main computer, if not for the price tag. 3200x1800. 25.3". It looks really good. Unfortunately, as is, it's a little outside of my wallet range.

There's a smaller $800 version too. 1650x2200. 13.3". That looks more usable.

To me, a major upside of the OkMonitor is the wireless connectivity. That's very, very nice. Especially if the computer dongle could be made small enough for use with my laptop while traveling, it would be a very nice solution.

Incidentally, in the past few days I have been testing Android + Kaleido3 as a general purpose device, and Termux-X11.

Kaleido3 is very usable; the recent waveforms and correct dithering algorithms allow video consumption with limited compromise (the framerate is high). And yes, coding is very doable (Termux provided the compilers/interpreters).

Termux-X11 adds the ability to have your desktop Linux natively on the Android device (so you may not need to use E-Ink displays as part of monitor devices, but already directly as embedded in a tablet used as active computer).

If anyone’s looking to jailbreak their kindle, the ‘mobileread’ forums are a great place to start.

Are e-ink displays ever going to get cheap? By now the basic patents should be running out.

https://news.ycombinator.com/item?id=26143779

The good news, maybe, is that "E-Paper" (transflective LCD displays), capable of much higher refresh rates (60 -- 180 Hz), though with greater power draw and lacking E-Ink (electrophoretic) display's persistence, but otherwise sharing bright-light / daylit visibility, are starting to appear.

What I've seen of E-Paper displays isn't especially encouraging on the cost front, as similarly-sized displays seem to have roughly comparable costs (~US$800 for a 13.3" display). But at least there should be a technologically-independent option, with the prospect for price competition.

I’ve been using Daylight Computer’s new Android tablet for a while now, which has a 60fps reflective grayscale LCD screen.

During the day it looks and behaves like E-paper, but with a much faster display rate. It’s also got a warm backlight for use at night.

When the backlight is off the contrast is lower than the E-ink Carta panel used in the Remarkable and Boox tablets, but the backlight and fast refresh really help make up for it.

https://daylightcomputer.com/

They seem to be sold out for quite a while, sadly. Good for them, though, I hope they means they’ll grow.

Watching videos/ interviews of the founder, it sounds like he’s very vey focussed on scaling this up to build affordable and durable wall sized versions of the display tech.

I’m certainly rooting for them. I hope they have more devices available soon

How's battery life?

Have you compared sessions where you're principally, say, reading books with a bookreader app vs. Web browsing, or using other apps?

My experience on the BOOX, an E-ink device, is that web browsing (Einkbro) consumes battery at ~10x the hourly rate that reading books (Neoreader) does. How much of that is active display, and how much is other CPU usage, I don't know.

My experience on the reMarkable 2 is that leaving it "off", showing the screen it displays when it detects that you haven't done anything for a while, will drain the battery in a matter of days, whereas leaving it "off", showing the screen it displays when you manually navigate into the shutdown menu and tell it to turn off, drains the battery in a matter of months.

I assume that none of the difference is in active display; the display is static in either case.

The Remarkable2 is an E-Ink device. I'd asked mattkevan as they are using a transflective LCD-based "E-Paper" device.

The technologies have a similar appearance, but utilise different technologies (electrophoretic vs. liquid crystal). Principle differences are the responsiveness of the display (LCD is far faster) and power consumption (LCD draws constant power, the display clears when voltage potential is removed, electrophoretic displays persist indefinitely when power is off).

As I'd noted in the comment you're replying to, I've used an E-Ink device for years, and am familiar with its power consumption characteristics.

Transflectve LCDs can't compete against Eink on contrast. They are inherently compromised on light transmission because of the polarizers and the modern desire for [back|front]light support.

I'm aware of LCD's inherent contrast handicap due to polarising filters. That said, E-ink also has a relatively low contrast ratio. Interestingly, that turns into a benefit under direct sunlight, where ink-on-paper is often too bright.

Finding current specs is challenging, but E-Ink Carta, as of 2013 (over a decade ago) was citing a 15:1 contrast ratio:

<https://wiki.mobileread.com/wiki/E_Ink_Carta>

Edit/Update: A more recent HN comment gives 12:1 as applying to most E-Ink displays as of 2020, with 8:1 being more common: <https://news.ycombinator.com/item?id=22832452>

I suspect current displays are somewhat better, and I'm seeing a "50% improvement" comment bandied about but without a corresponding contrast ratio. Earlier displays had an 8:1 ratio.

In practice, displays will have worse contrast with additional layers on top of the display, such as a Wacom tablet, capacitive touch, frontlight, and any surface "tooth" treatment.

E-Paper cites a 30:1 ratio, which would be far greater contrast:

<https://www.newvisiondisplay.com/transflective-lcds/>

I've had direct personal experience with E-Ink, but not with transflective LCD tablet displays.

I suspect that in practice the displays are reasonably comparable in terms of contrast.

> and the modern desire for [back|front]light support.

I had a keyboard kindle that came with a case that included a dim orange pull-out booklight.

I wish we could still get that. It was much more relaxing to read by than the modern uniform white glow from the page itself.

You can always use a clip-on book light, or other external light source.

<https://accessorytosuccess.com/blogs/tools/best-book-light-r...>

Every light in your link advertises (!) its multiple brightness and color settings. That makes for absolutely awful usability. I purchased a light like that, and it's terrible.

Give me an actual booklight where the settings are "on" and "off".

(Bizarrely, the light settings on a Kindle Oasis are barely better - since the light is controlled by an internal menu, as opposed to a hardware control, it can't be operated unless you can see the menu. This means that it isn't possible to have the light off during the day and turn it on when it becomes dark - if it's dark, and the light isn't already on, it can't be turned on. My conclusion is that there are no device manufacturers who understand how or why someone might want to use a lamp.)

How about a white book light with a piece of orange/yellow plastic over it (like a stage lighting gel).

I was simply pointing to the general concept.

I suspect that there are simple, single-colour, single-level clip-on lights.

Or, you know, conventional room lighting / reading lights.

He calls it the broken nature of the patent system, but I'm sitting here wondering why the creators of that technology shouldn't be handsomely rewarded for it, for a period of time? It's not like they're sitting on it (Creative Labs comes to mind), but rather releasing displays that just make devices cost more than they otherwise will.

A similar thing happened the tech behind Wacom devices--they enjoyed market dominance, the patent ran out, and now we have super cheap high-precision digital art devices.

From further down the thread, it seems it has been well beyond two decades and the original patents are already long expired. They are not playing fair - they are evergreening their patents with marginal changes which is illegal in countries where IP laws aren't a joke unlike the US.

The competition is still pretty expensive. The e-paper display I am using in my digital calendar is not from eink (as far as I’m aware), but still costs about 50 Euro if you buy a single one: https://www.waveshare.com/7.5inch-e-paper-hat.htm

It’s the main cost driver of my calendar, it basically forces the price point: https://shop.invisible-computers.com/products/invisible-cale...

I was about to buy one of these until I saw it relies on a backend service that you provide.

Any thoughts/plans on allowing a customer to self-host the backend? Or would you publish specs so someone could build their own?

I love the idea of this, and we would love to have one of these in our house, I've just been burned too many times with fully functional physical products bricking because the company behind it goes away.

I know you say you plan to support it for a long time, but everyone says that. :-(

It’s on the roadmap, but to be frank, other items are before it. It’s complicated and while I had a few people ask for it, I don’t think it’s something that most people need.

I know everyone says they’ll support their hardware for a long time and then they don’t. And of course I cannot give a guarantee.

But I have no masters to report to. No VCs and no Directors or CFOs.

So if I want to keep the backend running, I can just keep paying 20 Euro a month to Hetzner and keep the server updated.

It's a nice sentiment, doesn't solve the bus factor though. I'd also be keen once there is an open source backend. I might still pay for you to host it, but I want the option to not turn it to ewaste if you don't look before crossing the road.

Totally fair answer! Thank you...

For what it's worth, I've been following your project here and on Instagram for a year or two, keeping an eye out for the day there is local API support. I haven't bothered to even request it until now, since I see at least one person request it in what feels like every thread. Inkplate seems to be the only thing close to competition right now.

The patents have nothing to do with it. E-ink is expensive because it's a niche product with low scale - LCD screens are produced by the BILLIONS per quarter, and you probably have a dozen different devices with one. E-Ink does basically nothing that an LCD can't substitute for, and it's more expensive than LCD so nobody bothers.

"Patents" are a conspiracy cited without real evidence. It ignores that *E-INK HAS COMPETITION* (DES/Display Electronic Slurry screens). If E-ink corp were price-gouging then GoodDisplay would have eaten their lunch by now.

To be specific here, the conspiracy isn't that E-Ink patents exist - E-Ink patents do exist (some expired, but E-Ink corp are registering new patents as they innovate), but there are tons of LCD patents also. The conspiracy is the claim that patents are causing price-gouging and high prices that hold up adoption of the tech.

Why jailbreak? Just use internal kindle browser to stream screenshots of your desktop.

That would indeed be much simpler! I'm skeptical that the browser is powerful enough to handle a usable frame rate since every frame would have to go from the network -> DOM -> browser app memory -> frame buffer. The browser can barely keep up with the Kindle store / Goodreads, but it'd be nice to be proven otherwise since it'd make it much easier to get this working ootb on brand new Kindles.

i had similar idea to turn kindle to second monitor

https://www.youtube.com/shorts/6dcc0hLe0mc

frame rate was too bad so i just bought dasung paperwhite :)

Posted on GitHub:

"unfortunately I lost the Go source code"

Followed up with "but it was pretty simple, like under 30 lines"

So simple in fact, that it wasn't quickly rewritten and added to GitHub...

I should stop writing code in files like /tmp/x.go no matter how throwaway I think the code might be. I still have the linux/armv7 binary if anyone wants it lol.

Oh man, apparently I'm not alone in using /tmp/ as my storage space. I like it because it's self-cleaning!

You could have /home/junk2020, /home/junk2021, /home/junk2022 etc. Still self-cleaning, but it's once a year.

Or I could have /home/junk, self-cleaning but never!

That is me, I have `/home/delme` since forever!

You know what else is self-cleaning?

   /dev/shm

The advantage being that it does not even touch the disk.

One can use tmpfs for /tmp as well (and I do it).

I present you my most used shell function:

    cdtmp() {
        cd $(mktemp -d)
    }

That's fantastic, thanks! I always used to do this by hand. Though one downside is that the name is random, and it's hard to go back if you CD out. I might use diceware to make a memorable random name.

I agree that sometimes that is a problem, so I find out the latest tmp directory with ls -tr /tmp | tail. But using nicer names would help with that.

So I took your tip and now I have

    cdtmp() {
        local name
        name=/tmp/$(diceware --no-caps -d - -n 2)
        mkdir $name && cd $name
    }

I decided not to worry about the directory existing already, or of the other checks mktemp -d would do for me in my single-user system.. I suppose mktemp -d -t cdtmpXXX would work almost as well. Thanks for the idea!

Thank you! That's very neat, I'll implement this myself as well.

I'm team /home/user/Downloads/tmp

This resonates funnily with "I hacked this together last night for fun" a bit down the page.

"It is impossible to separate a cube into two cubes, or a fourth power into two fourth powers, or in general, any power higher than the second, into two like powers. I have discovered a marvelous proof of this, which this margin is too narrow to contain" - Pierre De Fermat

> It is impossible to separate a cube into two cubes

Later disproved by the Banach-Tarski theorem. ;D

where is this posted? i didn't see in in gist.github link.

It's under the section "step 2"

The easy way to do this is a Boox reader with the Superdisplay app.

Perfect demonstration video, thanks for that.

They didn't answer the most important question: was it worth it?

Too early to tell. It's not useful as a primary monitor, but it's great as a secondary. In its current form, the frame rate is good but the latency is awful. This makes for a bad typing experience, but there are plenty of usecases where I don't need to type. And even in situations like a chat window, where low latency typing feedback is critical, I can just have the input text box on my LCD monitor and have the chat history on the Kindle since it's mostly static. It needs some work to get there tho, but for now, this is a good start.

An E-Ink device would be perfect to play nethack/slashem, MUDs, IF games, turn based games and Chess/Go.

There is pbchess for Chess. It supports multiple ereaders. If I recall correctly, it includes a few other games and applications. For IF, QtFrotz was ported to Kobo devices. (For what it's worth, the main drawback with IF is the lack of a hardware keyboard on most e-Ink devices.)

What's unclear here is the refresh rate, but knowing the Kindle(s) this is hardly faster than 0.5fps

It looks like it has the ability to do partial refresh

updated the gist: I'm getting close to 3-4 frames per second! this is only possible because of the partial screen refreshes since most pixels don't change between consecutive frames

Oh wow. That's nice! Yes, if it does partial refreshes then the refresh rate might be way faster than I expected.

Awesome!

For me, that would be fine. It's common to have some reference or other piece of information that I want handy but doesn't change much.

Here's my old Kindle Touch 2 running a hacky Android 4 port attempt and a Game Boy emulator: https://i.imgur.com/m7ZZ1Xm.mp4 I'd say more like 2 - 3 fps. Not sure why there are random black lines. Display driver doesn't handle the demand of constant update very well. I normally use it as an e-ink picture frame.

Independent of the methods indicated here (screen capture + imagemagick conversion), there's the underlying question of E-innk hardware capabilities. I can speak to the latter.

E-Ink screens are usually capable of a number of different refresh / display modes, which trade higher-quality visual appearance (crispness, greyscale, ghosting) for slower refresh.

Refresh rates typically range from ~2-4 Hz at highest quality to 16--60 Hz at lower quality, but faster-updating modes. For most E-ink devices I've seen there are typically four modes, "Normal/Regal" (highest quality), "Speed", "A2", and "X-Mode" (fastest refresh).

"Normal" is best for reading static text. "Speed" is sufficient for terminal-based sessions (I have Termux installed on my Onyx BOOX tablet), and most interactive apps (e.g., Web browsers, Podcast apps). I find little practical distinction between "Speed" and "A2". X-Mode does show considerale ghosting, but is indeed capable of video playback.

Typically it's also possible to set the full-refresh interval (now many repaints are premitted between full refreshes which clear ghosting but give a distinct "flash" update.

E-ink has a number of compromises, but is quite usable. Apps which are designed with its capabilities and limitations in mind are much better suited. Mostly that involves full-screen pagination of content rather than scrolling. Given the ubiquitous use of touch-based scrolling in most Mobile applications, this can be somewhat frustrating. I tend to use dedicated e-ink apps (such as Onyx's own NeoReader book reader), apps tuned for E-ink such as Einkbro, a Web browser, or terminal-based apps which work well in a text-based context.

I thought thought it was called "rooting" when in reference to an Android device.

Maybe it's not called jailbreaking on Android phones because it's more or less a supported feature, not something the phone tries to prevent you from doing. On other devices like a Kindle you're actively circumventing security measures.

"rooting" started up by meaning specifically to gain root access to the os. jailbreaking includes this step too, but out of need.

the nice variety of root-access apps you could normally install but unable to run become available after rooting. for many that is enough, without requiring kernel-level changes to make this work. besides this conceptual difference, they both are used interchangeably.

for kindle jailbreaking makes sense as there is no built-in mechanism to support new features/apps.

This eReader firmware has a built-in VNC application - https://inkbox.ddns.net/

I am wondering if anyone used https://elekscava.com/ device for similar purpose?

Anyone have a write-up for doing this with a Remarkable 2?

Fairly sure you can run a vnc client on a remarkable 2. I've been on the fence about getting one for a few years and I'm not super up to date on them, but a quick search turned this up https://github.com/matteodelabre/vnsee

I rely in mine so much that I'm not game enough to try that lol

I stupidly upgraded my Kindle 4 to the latest firmware, and apparently there's no jailbreak for that and no way to downgrade.

Welcome to the skinner box

i suppose this would be far more intresting if you should what various ways you ca use a kindle and also maybe provide an 1-click way to jail break kindle and upload a YT video. dont forget to add 'for educational purpose' in the title so that amazon doesnt comes after you.

Someone get Apple Books on a Kindle and I'll pay you a million dollars.

Why trade one walled garden for another? Just use something like Calibre and combine it with something like Kavita.

What does combining them get you?

I use Calibre but hadn't heard of Kavita and I'm not clear what Kavita gives me that I don't already have with Calibre?

I hadn't heard of Kavita either, but it looks like it's a lot prettier than Calibre, and (perhaps) has better a better reader. It looks like it doesn't manage format conversion and syncing though, which I guess is why you'd use both it and Calibre together.

Calibre is a very ugly tool for converting formats, fixing metadata, and all the other worst parts of managing an ebook library. The single author's eccentricities are apparent but it was first and it does complete those jobs. If you slog through the setup and quirks, you at best get an iTunes experience from 10 years ago, and I just don't like using it to actually manage my library.

Kavita is more like Plex, where when you have your library in something of a decent form it makes using your library a much better experience.

Its also the only tool I know of that handles both manga and ebook libraries well.

Apple Books has some rare exclusives. To name one, all of Norman Berrow's novels are only available there.

Can i hold you to that? :)

This article completely glosses over what is presumably the first step of making this work, which is getting a shell on the Kindle. The only resource is some random forum bulletin board post? Huh?

What do you mean "random"? Does the post lack some info or why is it not good enough?

Posts in forums don’t age well, change URLs, become outdated, and so on. If you want a durable thing, you should add that to the project description.

I don't think phpBB threads ever change URL these days. It's only unreliable if the forum is managed by a video game company, because they delete the whole forum every now and then to renew their website. But MobileRead is well-known and enduring.

I suspect it's less that the forum will change URLs as that the URLs listed within some arbitrary forum post will become outdated as the referenced source moves or is deleted.

Linkrot, in other words.

Documentation in Wiki-based formats is more resilient against this as posts can be subsequently edited.

Why is the source-of-truth record for a set of complex technical instructions in a bulletin board board of all places? Instead of, you know, checked in as code in a version-controlled repository, like basically all other software?

Be the change you want to see in the world. In the time you spent complaining about it here you could have made such a resource. Don't ask the Internet in general to do it for you.

No, I could not have, because I don't own a Kindle nor do I have any way of exercising the instructions. I'm just calling out that this is an asinine delivery format.

If you don't have a Kindle, why do you care where Kindle owners keep their technical information about Kindles?

Jailbreaks are highly firmware and hardware specific. I've only seen one specific combination (5.13.5, PW3), but the LanguageBreak authors have seen hundreds -- including mine -- so I have no additional insight or instructions that the extremely thorough LanguageBreak thread doesn't have.

> random forum bulletin board post

As opposed to a random gist? :)

I’m a software developer and rooting my kindle genuinely took a couple hours from googling to it working. It’s definitely not for the light hearted

Faint of heart was the expression I was looking for I think, haha

Best RickRoll ever!

It looks like the entire purpose of the project was to turn "Never Gonna Give You Up" into "Take On Me" in the most indirect and random way possible.

No no. You are not supposed to rick roll when showcasing display hacks. For displays you use Bad Apple.

That video has always felt unprofessional to me. I wish we'd choose something else.

How professional should the video be if I want to show something animated on my Etch a Sketch?

It's one of those things where if someone does the work, they're allowed to show off how they like.

Next time you do an interesting display mod or port, you can choose whatever video you like.

I meant it's a bit like the Lena image in digital image processing.

I get that the original author of the series is above board, but the fandom around touhou is full of enough toxic people that it's often the first thing one encounters or associates with the brand. Kind of like the tug of war with Pepe, but much worse.

I just now did a Google image search for "touhou" (just that term, no quotes) with safe search enabled and you might guess what came back. And these characters are supposed to be children.

I don't want to be a nanny or intrude on people who most likely mean no harm, but if video demos are to have a "standard" test video, should it really be Bad Apple? If you've got something really cool to show off, don't spoil it by associating it with that.

The fact that we still call it "jail breaking" is kind of insane. We bought this hardware, "using it however we like" is literally how ownership works.

That's certainly how it should work, but how it should be and how it is are not the same thing. There's a reason we're fighting for Right to Repair laws.

Well the corporate greed locks it up for our safety

Duplicate? https://news.ycombinator.com/item?id=41155177

Merged hither.

Thanks!!

Reply on news.ycombinator.com