The ReTerminal Sticky Is An E-Paper Display Begging You To Hack It - Aftermath

e-paper has been having a bit of a moment recently. First, the Boox Palma shrank the form factor of eReaders down to something a bit more pocketable and less proprietary than the Kindle. Then, open source developers seized upon and installed custom firmware on the Xteink X4 and X3, cheap no-frills eReaders that snap to the back of your phone and are just enough for many people. The X4 was clearly a huge success, as Xteink is following this up with the X3 Pro and X4 Pro and Boox has announced their micro ereader competitor the Boox Picco. But bare bones e-paper is anyone’s game at this point, and so Seeed Studio has thrown their hat in the game with the reTerminal Sticky, an even cheaper and more capable small magnetic eInk display that leans in on the entire angle that made the X4 a viral sensation.

I have at least 9 of these in my house, they're in tons of DIY projects..

SeeedStudio is a company near and dear to my heart because I solder circuit boards for fun. They are a Chinese company mainly aimed in the same space as Adafruit and M5Stack: tiny circuit boards, displays, sensors and IoT devices tailored for tinkerers who like to get their hands dirty. Seeed made their name in the space with the Xiao (literally “small” in Chinese), a tiny square microcontroller that has found its way into many keyboards and devices, including a split keyboard I own called a TOTEM. Many of the official devices for Home Assistant are produced by Seeed, and their products tend to have a professional fit and finish while still being aggressively targeted in the same price range as no-name stuff you buy from AliExpress.

It’s worth noting that, like all companies in the smart home space, Seeed have doubled down on AI branding, with the Sticky’s box declaring it “The AI Sticky Note.” While that’s unfortunate but understandable given what the company makes, it’s also entirely optional given the open nature of the hardware. The Sticky gives you plenty of ways to ignore that specific element of the device.

The Sticky is the newest entry in the reTerminal line, a series of open smart home-enabled e-paper displays. It costs $50 at the time that I’m writing this, below the MSRP of the X3 on Amazon by about 19 dollars. Xteink also announced they were ending the current version the X4, most likely to refresh the device in the near future.

The Sticky is roughly the same size and shape as the X4 while being a more capable device that features a touch screen, a mic, and higher pixel density. By default a beeper is enabled, which is something you are instantly going to want to turn off because it is quite annoying. The screen is also glossy, which is a pity as I very much would have preferred the option for a matte one. The Sticky comes stock with Seeed’s software Seeedash, which itself is not unattractive and lets you use the device like a smart sticky note, a to-do list, smart home frame and a clock.

The default firmware is basically a calendar, a notes app, and an AI dictation thing. Not what I'm interested in, frankly.

The “AI” part of the device is that you can use it to do AI dictation using the internal mic or have the device show your Codex usage, and while I am not going to do either of those things I can imagine the kind of person who might. Unsurprisingly for a spartan device, transcription is not done on-device but in the cloud, which is where my interest in it ends. The Sticky also features a temperature and humidity sensor and a gyroscopic motion sensor, which is quite a lot for a device that costs 50 bucks.

If the device was just a fridge magnet clock and sticky note with AI features that I am clearly not the audience for, I would absolutely not buy it. But that functionality is purely perfunctory, and Seeed has done something quite smart here and fully leaned into the real reason why anybody actually buys these things: hacking them and installing stuff you actually care about.

This is not a company turning a blind eye to what users do; the website itself prominently boasts in advertising that the device can be used with ESPHome, OpenDisplay, TRMNL, and CrossPoint Reader (the community eReader software made for the Xteink X4). Basically anything you can think of can be flashed on it. Whereas Xteink had a minor dustup on Reddit earlier this year about if it would continue to allow users to flash CrossPoint on their devices (which has since been addressed by the company), Seeed has basically told its users “yeah, go nuts man, we’re not your dad.”

This is how computers should actually work. The reality of many IoT devices is that they are simply off-the-shelf parts refashioned into a novel form factor. The ESP32 series of chips in particular are in everything from light bulbs to smart sensors and even to open source music-making computers, with the main distinction being “do I actually have control of this hardware or is it a little cop I paid to narc on me?”

A key distinction between Seeed and many smart home companies is they actually make hardware instead of outsourcing it, slapping a monthly service on it, and selling it at Best Buy to clueless moms. Almost every smart home camera is a cop when you get it, and Amazon’s entire hardware line is an exercise in selling the least open hardware possible at either a severe loss or questionable profit and often for nebulously-defined goals as is the case with Alexa. Much of that stuff ends up as ewaste or gets increasingly shittier and full of ads unless you manage to find a specific model that you can jailbreak like the Echo Show or that one Fire Cube you can install CoreELEC on to. Kindle hacking has become increasingly popular for a good reason, as it allows you to turn an old forgotten device in a closet into an object with purpose and intent. Makers have gotten increasingly good at using e Ink in a DIY context, as is evidenced with the Steam Machine’s Inkterface and companies like TRMNL leaning into user sovereignty over their devices. The reTerminal Sticky is simply what happens when a company that actually makes stuff reads the tea leaves and gives people what they want.

The only quibble I have with the reTerminal Sticky as an eReader specifically is that the screen is glossy. I do not love glossy screens if I can avoid them, doubly so if I am supposed to touch them with my fingers and read text on them. There’s something nice about that slightly rough texture that matte eReaders tend to have, and scratches are easier to hide. It did not take long before I managed to ding it up slightly, and Seeed Studio needs to put out a screen protector or folio case if they want to take the eReader market seriously. In practice, however, it is less distracting than a smartphone screen and something that could be easily addressed with either an alternate model or a matte screen protector, although the upshot is that text does look handsome on a glossy screen.

With the exception of that one specific element, the device is a layup. Text looks slightly clearer than the X4, although still what you’d expect for 50 bucks. Unlike the non-pro Xteink devices it has a touch screen natively, and the exact same ecosystem for CrossPoint Reader is already in beta and easy to flash. It has a USB-C port, which should not be novel but the X3, X3 Pro, and X4 Pro all dropped the port in favor of a POGO pin connector for some reason which, despite not being proprietary, basically nobody wants. Like the base X3/X4 and unlike the new X3/X4 Pro models the Sticky does not have a backlight, but I would pay the extra money for that in a heartbeat if they offered it.

Because the device is ostensibly meant to be a sticky note, the N52 magnets are not in the center but in the corners. Unlike the X4 they are sturdy as hell, and when you put this thing on your fridge it won’t fall off from swinging back and forth. Seeed is clearly aware that people will want to mount this on their phone and have included an adhesive mounting ring as well, and like the internal magnets they are not screwing around. It’s a substantial ring with a slight lip and the adhesive is strong, although I’ve not put it through a torture test. Leaning into the phone ring being adhesive and optional also solves one of the bigger issues with the X4, which is that the device would not sit flush with your phone and would run into the camera bump. Not only does the added depth make it easier to position the device, it also positions the eReader higher than the camera bump, so rotating it 180 degrees on my iPhone 15 Pro was possible without hitting the camera bump. Though the depth of the ring made the device a little bigger in my hand, it’s absolutely not going anywhere unless you want it to.

Since I wrote up the Xteink X4, the community made CrossPoint Reader firmware has become increasingly easy to flash. Just insert a FAT32 formatted microSD card, open their website, connect your device via USB-C, hit flash, and reset the device. The microSD card is pretty deeply inset, so you may need a toothpick or something similar to insert it. The flashing process stands in stark contrast to hacking a Kindle, which is an elaborate yet rewarding process that has its own wiki and uses various exploits named “AdBreak”, “Nosebleed” and “WinterBreak”. Like the Xteink and Palma, ePubs can be thrown directly onto the SD card or via WiFi, and CrossPoint Reader can now preemptively optimize the text for the limitations of the ESP32.

Though the Sticky lacks the second row of buttons of the X4, the touch screen more than makes up for this. While I was initially worried that the sensitivity of the screen would lead to unintentional page turns, the touch behavior can be disabled and in CrossPoint Reader feels organic and predictable. CrossPoint can also use the internal gyroscope of the device for page turning, with tilting the device backwards or forwards advancing the page depending on the setting. This is off by default and not something I have gotten the hang of again, but pretty neat to have in a cheap little gadget.

As previously mentioned, a detail that differentiates the reTerminal Sticky from the Xteink is that Seeed Studio does not care if you install third party firmware on it and would, in fact, love it if you did that. Not only did Seeed reach out to several open source e-paper projects prior to the release of the device, they have web-based flashers for each of them on their own website. CrossPoint Reader, CrossInk, TRMNL, ESPHome and OpenDisplay are prominently shown on the Sticky’s homepage. It’s quite easy to flash the device and get the firmware up in running in a matter of minutes with little or no technical background, although I did run into one issue that set me back a few days before Seeed clarified one wrinkle in the process: For the majority of the non-eReader firmwares, you should not have a microSD card in the device when you flash it. The technical reason for this is that the eInk display and the microSD card share the same SPI bus, but Seeed told me that they are working on resolving this.

The reTerminal Sticky is the ideal target for software like TRMNL, a piece of software meant to be an everything hub for networked e-paper displays. The company sells their own devices, but the software can be installed on hacked Kindles, or many open e-paper displays. You can host your own service locally for free, or (currently) pay 50 bucks once to register your own device (or BYOD, as TRMNL calls it.) TRMNL works on a plugin system to synchronize services like your Google Calendar, a weather service, apps like ToDoist and TickTick, or whatever you want to code for it. From there, you can set up a plug-in playlist for your device to cycle through at regular intervals. Some of these are as corny as you’d expect from an open e-paper display service, like a plugin that displays different facts about Ferengi from Star Trek, while others are more practical. One of the cards I had in my playlist linked TRMNL to my Letterboxd account to see a quick breakdown of recent movies my friend saw. It’s actually quite pleasant and a bit futuristic to go to your fridge for a snack, see an updating magnet and remark “Oh, Will gave The Samurai And The Prisoner five stars, I gotta remember to buy tickets.” If a company tried to pull that shit with my fridge I’d put it in a faraday cage, but it’s entirely different when you choose to do that.

Open Display is simple and works over Bluetooth. You can use it to update a simple image, or connect it to Home Assistant.

OpenDisplay is way easier to set up while also being far more simple and local. You can control anything you want on the device via bluetooth and can use it to send doodles or text to the device. OpenDisplay is also an open platform and can be used with any compatible sender like Home Assistant. It’s a much simpler interface and program than TRMNL, but if you are looking to treat the Sticky like a sticky note or something more direct and basic, that simplicity is a strength. The devs were also quite nice when I bugged them for support help on Discord, so I’d like to thank them publicly for that.

There’s plenty of other apps in the “Playground,” the part of the site that Seeed devotes to development. While rotating through the various off-the-shelf firmwares, I installed a bunch of different apps to it. There’s one called Sticky Lotus that turns the touch screen into a two/four way life counter for Magic The Gathering. Another firmware is a recreation of 2048 that utilizes the touch screen. I’m sure the Sticky will be a destination for many vibe coded one-off projects that are promptly abandoned, but in all honesty there are far worse things you could put on GitHub, and it doesn’t really reflect poorly on the device itself. Frankly, I’m just happy that people are excited for the possibility of a tiny, cheap computer.

Since my review of the Xteink X4, I have seen a lot of traditional reviews attempting to reconcile this new category of devices – e-paper displays connected to cheap microcontrollers and running community firmware – within the framework of existing eReaders. Many bring up the lack of a storefront, while others knock them for being a tiny bit hacky and requiring a bit of knowhow to get up and running. And while this could be construed as fair feedback for a broad, traditional consumer base that would purchase a Kindle (I would love a version of these devices that worked with Libby, for example), it fundamentally misunderstands that the audience for these devices is people who are fucking sick of Kindles. Devices like the Xteink X4 family and the reTerminal Sticky are for people who have a loose folder of ePubs on a Dropbox or hard drive. It is for people who want to fill a 32gb microSD card up with erotica downloaded from AoE3. These are not devices that attempt to be everything; they are meant to be inexpensive and dedicated.

Though these devices are similar in function to traditional eReaders, they have more in common spiritually with the ever-proliferating category of retro handhelds, devices no reviewer would dream of treating the same way they do a traditional console or handheld. Saying “you’re going to have to find epubs” is a bit like saying “you may have to find ROMs” when talking about the Retroid Pocket; functionally a tiny bit silly and condescending to the reader. You would be shocked at the average person’s capacity to follow a wiki, a sticky on subreddit, or a fairly complex YouTube tutorial to completion if they are excited for a new, affordable and accessible device.

What Seeed Studio have done here has doubled down on the bet on the competency of its audience. They have seen that there is a niche but growing market for these small, cheap devices that Xteink kicked off, intentionally or not, and decided to run with it while selling it at a cutthroat price point. They have made a device that they would use, an e-paper display that leans into the DIY and open nature of the hardware they sell and the community that embraced the X4. And though I experienced a few hiccoughs at launch and I really wish that they sold a version in a matte screen (and maybe one in black), if the current price holds, it will sell like hotcakes. The reTerminal Sticky is not simply a cheap eReader; it is a dirt cheap magnetic swiss army knife eInk display with an ever-growing repertoire of flashable firmware. But most importantly, it is a device that reaffirms the truth that the ideal use case for a computer is whatever the user can imagine.