While we tend to think of Amazon’s e-paper Kindles as more or less single-purpose devices (which to be fair, is how they’re advertised), there’s actually a full-featured Linux computer running behind that simple interface, just waiting to be put to work. Given how cheap you can get old Kindles on the second hand market, this has always struck us as something of a wasted opportunity.
This is why we love to see projects like Kindlefusion from [Diggedypomme]. It turns the Kindle into a picture frame to show off the latest in machine learning art thanks to Stable Diffusion. Just connect your browser to the web-based control interface running on the Kindle, give it a prompt, and away it goes. There are also functions to recall previously generated images, and if you’re connecting from a mobile device, support for creating images from voice prompts.
All you need is a Kindle that can be jailbroken, though technically the software has only been tested against older third and fourth-generation hardware. From there you install a few required packages as listed in the project documentation, including Python 3. Then you just move the Kindlefusion package over either via USB or SSH, and do a little final housekeeping before starting it up and letting it take over the Kindle’s normal UI.
Given the somewhat niche nature of Kindle hacking, we’re particularly glad to see that [Diggedypomme] went through the trouble of explaining the nuances of getting the e-reader ready to run your own code. While it’s not difficult to do, there are plenty of pitfalls if you’ve never done it before, so a concise guide is a nice thing to have. Unfortunately, it seems like Amazon has recently gone on the offensive, with firmware updates blocking the exploits the community was using for jailbreaking on all but the older models that are no longer officially supported.
While it’s a shame you can’t just pick up a new Kindle and start hacking (at least, for now), there are still millions of older devices floating around that could be put to good use. Hopefully, projects like this can help inspire others to pick one up and start experimenting with what’s possible.
Last last month, a post from the relatively obscure Good e-Reader claimed that Amazon would finally allow the Kindle to read EPUB files. The story was picked up by all the major tech sites, and for a time, there was much rejoicing. After all, it was a feature that owners have been asking for since the Kindle was first released in 2007. But rather than supporting the open eBook format, Amazon had always insisted in coming up with their own proprietary formats to use on their readers. Accordingly, many users have turned to third party programs which can reliably convert their personal libraries over to whatever Amazon format their particular Kindle is most compatible with.
Native support for EPUB would make using the Kindle a lot less of a hassle for many folks, but alas, it was not to be. It wasn’t long before the original post was updated to clarify that Amazon had simply added support for EPUB to their Send to Kindle service. Granted this is still an improvement, as it represents a relatively low-effort way to get the open format files on your personal device; but in sending the files through the service they would be converted to Amazon’s KF8/AZW3 format, the result of which may not always be what you expected. At the same time the Send to Kindledocumentation noted that support for AZW and MOBI files would be removed later on this year, as the older formats weren’t compatible with all the features of the latest Kindle models.
If you think this is a lot of unnecessary confusion just to get plain-text files to display on the world’s most popular ereader, you aren’t alone. Users shouldn’t have to wade through an alphabet soup of oddball file formats when there’s already an accepted industry standard in EPUB. But given that it’s the reality when using one of Amazon’s readers, this seems a good a time as any for a brief rundown of the different ebook formats, and a look at how we got into this mess in the first place.
Regular readers will likely remember the Inkplate, an open hardware electronic paper development board that combines an ESP32 with a recycled Kindle screen. With meticulous documentation and full-featured support libraries for both the Arduino IDE and MicroPython, the Inkplate makes it exceptionally easy for hackers and makers to write their own code for the high-quality epaper display.
For one thing, [Guy] has taken full advantage of the ESP32 microcontroller at the heart of the Inkplate and implemented a web server that lets you manage the reader’s library from your browser. This allows books in EPUB v2 and v3 formats to be uploaded and saved on the Inkplate’s SD card without any special software. There’s currently support for JPG, PNG, BMP, and GIF images, as well as embedded TTF and OTF fonts.
As of this writing EPub-InkPlate supports both the six and ten inch Inkplate variants, and uses the touch pads on the side of the screen for navigation. While it’s on the wishlist for the final 1.3 release, the project currently doesn’t support the Inkplate 6PLUS; which uses the backlit and touch compatible displays pulled from Kindle Paperwhites. With shipments the new 6PLUS model reportedly going out in November, hopefully it won’t be long before its enhanced features are supported.
With the rising popularity of ebooks, it’s more important than ever that we have open hardware and software readers that work on our terms. While they may never compete with the Kindle in terms of units sold, we’re eager to see projects like EPub-InkPlate and the Open Book from [Joey Castillo] mature to the point that they’re a valid option for mainstream users who don’t want to live under Amazon’s thumb.
While the price of electronic paper has dropped considerably over the last few years, it’s still relatively expensive when compared to more traditional display technology. Accordingly, we’ve seen a lot of interest in recovering the e-paper displays used in electronic shelf labels and consumer e-readers from the likes of Amazon, Barnes & Noble, and Kobo. Unfortunately, while these devices can usually be purchased cheaply on the second hand market, liberating their displays is often too complex a task for the average tinkerer.
Enter the Inkplate. With their open hardware ESP32 development board that plugs into the e-paper displays salvaged from old e-readers, the team at e-radionica is able to turn what was essentially electronic waste into a WiFi-enabled multipurpose display that can be easily programmed using either the Arduino IDE or MicroPython. The $99 Inkplate 6 clearly struck a chord with the maker community, rocketing to 926% of its funding goal on Crowd Supply back in 2020. A year later e-radionica released the larger and more refined Inkplate 10, which managed to break 1,000% of its goal.
For 2021, the team is back with the Inkplate 6PLUS. This updated version of the original Inkplate incorporates the design additions from the Inkplate 10, such as the Real-Time-Clock, expanded GPIO, and USB-C port, and uses a display recycled from newer readers such as the Kindle Paperwhite. These e-paper panels are not only sharper and faster than their predecessors, but also feature touch support and LED front lighting; capabilities which e-radionica has taken full advantage of in the latest version of their software library.
Even with the recent price reductions on stand-alone panels, picking up a used Kindle is still arguably the most cost effective way to get your hands on a large electronic paper display. Especially when you consider the Kindle includes a battery, case, and electronics to drive the display. Bending the Kindle software to your whims introduces its own unique challenges of course, but with a little tweaking, an old e-reader can live again as whatever you wish it to be.
Case in point, the OkMonitor project by [Brendan Sleight]. Using a somewhat dizzying combination of software and hardware, he’s figured out a way to turn an older Kindle Paperwhite into a plug-and-play HDMI monitor. Is it a great monitor? Far from it. As the name implies, the best you can hope to get from this solution is an OK monitor. But at least it’s something.
There’s quite a bit going on behind the scenes in OkMonitor, which [Brendan] describes through a slideshow on the project page. But the high-level idea is that a Raspberry Pi 4 with a simple USB HDMI capture device takes the video input and converts it on the fly to a scaled down Kindle-friendly format. The converted video is streamed over WiFi to the jailbroken Kindle with netcat, where it’s displayed by a native video player. In the video after the break you can see that the end result looks pretty impressive, even if there is a considerable delay involved.
Despite the demonstration [Brendan] has put together for OkMonitor, we can’t say we’d watch many films over this setup. But the fact that you can plug any HDMI device into the “base station” and have the video sent out to one or more Kindles is undeniably impressive. It’s definitely worth a close look, even if you just take some of the concepts of this project to get your own Kindle repurposing idea off the ground.
On the whole, hackers aren’t overly fond of other people telling them what they can and cannot do with the hardware or software they’ve purchased. Unfortunately, it’s becoming more and more difficult to avoid DRM and other Draconian rules and limitations as time goes on. Digital “eBooks” and the devices that are used to view them are often the subject of such scrutiny, which is why [Joey Castillo] has made it his mission to develop a open hardware eReader that truly belongs to the user.
[Joey] has been working on what he calls the “The Open Book Project” for a few months now, and he’s just recently announced that the first reader has been successfully assembled and powered up. As is usually the case, a few hardware issues were identified with this initial prototype. But it sounds like the device was largely functional, and only a few relatively minor tweaks to the board layout and components should be necessary before the hardware is ready for the masses.
If you’re feeling a bit of déjà vu seeing this, don’t worry. The Open Book Project has taken a somewhat circuitous path to get to this first prototype, and [Joey] had previously developed and built the “eBook Feather Wing”. While they look very similar, that earlier incarnation required an Adafruit Feather to operate and was used to help refine the firmware and design concepts that would go into the final hardware.
The Open Book is powered by a ATSAMD51N19A processor with a GD25Q16 2MB flash chip to hold the CircuitPython code, and a microSD slot to store the actual book files. It also features support for audio output via a standard 3.5 mm headset jack, an RGB status LED, and expansion ports that tap into the I2C interface for adding whatever other hardware you can dream up.
One of the most interesting aspects of this Creative Commons licensed reader is the extensive self documentation [Joey] has included on the silkscreen. Every major component on the back of the PCB has a small description of its purpose and in some cases even a breakdown of the pin assignments. The idea being that it not only makes the device easier to assemble and debug, but that it can also explain to the curious user what everything on the board does and why it’s necessary. It’s a concept that makes perfect sense given the goals of the Open Book Project, and something that we frankly would love to see more of.
[Marc Juul] presented his work on a FOSS operating system for older-model Kindles at HOPE XII as a way to avoid Orwellian monitoring of the user’s reading habits, so it’s interesting to see somebody take this idea to the next level with completely libre reader hardware. Unfortunately none of this addresses the limited availability of DRM-free eBooks, but one step at a time.
You don’t have to be an avid bookworm to find use for an e-book reader. Take your local wedding band for example: with a big repertoire of songs to cover, you don’t really want to drag huge folders full of chords and lyrics around, tediously browsing through them to find the correct one for every new song. Even the biggest tree corpse enthusiast cannot deny the comfort of an e-book reader here. And since turning the page boils down to simply changing the content on a display, you don’t necessarily need to use your hands for that either. With that in mind, [mosivers] built a WiFi foot switch for his musician brother’s Kindle to flip backwards and forwards through the pages.
After jailbreaking the Kindle and installing busybox, [mosivers] set up a web server to serve two CGI scripts that write the previously recorded input events for forward and backward flipping respectively to /dev/input/event0, essentially simulating a touch screen press that way. The foot switch, as counterpart, houses a battery-powered ESP8266, acting as access point for the Kindle to connect to, and requesting those page flipping CGI scripts whenever one of its two buttons is pressed.