Seeed Studio has released the reTerminal Sticky, a 3.97-inch touch-enabled ePaper device that sticks to a wall or a refrigerator with magnets. It is a small slab built around an ESP32-S3, and pressing a button and speaking turns your words into a note on the screen. Beyond the stock family message board, the whole firmware can be swapped out to turn it into an e-reader or a smart home display, which puts it in an unusual position among small ePaper gadgets.
Filling the gap between paper and a phone
A paper note on the fridge is impossible to miss, but rewriting it every time is tedious. A shared list on a phone is easy to update, yet it gets buried under notifications and nobody looks at it. The reTerminal Sticky aims at the space in between: an always-on E Ink panel that shows only the information the whole household is meant to see.
The unit measures 106 x 65.5 x 7.3 mm and weighs 70 grams. A magnet is built into the back, so it attaches directly to a refrigerator or a steel door. For non-metal surfaces, an accessory magnetic ring handles the mounting. At just 7.3 mm thick, it sits on a wall with roughly the presence of a pinned card.
The display is a 3.97-inch monochrome ePaper panel at 800 x 480 with 4 levels of grayscale. Pixel density lands around 235 ppi, which keeps text from breaking up compared with many E Ink devices in this size class. It supports capacitive touch, so the on-device app in view can be changed with a finger.
What separates the reTerminal Sticky from a generic ePaper display is that it has an input path. The device carries a single PDM microphone and an AI Voice button, and speaking after pressing the button writes the content to the screen as a text note, a to-do, or a reminder. The feature relies on AI processing through the vector instructions in the ESP32-S3R8, which is what Seeed Studio is referring to when it calls the device AI-powered.
The sensor set is reasonably complete. A temperature and humidity sensor and a 3-axis accelerometer are on board, usable for showing room temperature or flipping between portrait and landscape based on orientation. A buzzer, page up and down buttons, and an internal reset button round out the hardware.
The main specifications are as follows.
| Item | Details |
|---|---|
| SoC | Espressif ESP32-S3R8 (dual-core Tensilica LX7, up to 240 MHz) |
| Memory | 8 MB PSRAM |
| Storage | 32 MB flash, microSD card slot |
| Wireless | 2.4 GHz WiFi 4, Bluetooth 5.0 LE |
| Display | 3.97-inch monochrome ePaper, 800 x 480, 4 grayscale levels, capacitive touch |
| Audio | 1 PDM microphone |
| Sensors | Temperature and humidity sensor, 3-axis accelerometer |
| Power | USB Type-C (5V/1A), 750 mAh battery |
| Standby time | 7 days on average |
| Dimensions | 106 x 65.5 x 7.3 mm |
| Weight | 70 grams |
Standby time is quoted at 7 days on average. For static images and other uses where the screen is rarely redrawn, Seeed Studio says a power saving mode extends that considerably, though the company is still measuring exactly how far.
The stock firmware lacks Japanese, but the whole thing can be replaced
Out of the box, the firmware pairs with Seeedash, a companion app coming to Android and iOS. Sending notes is its main job, and it can also push photos or surface the status of an AI agent you are running. Language support, however, currently covers only English and Simplified Chinese, with Seeed Studio saying more are in progress. For anyone who wants to use it in Japanese, that is the immediate hurdle.
In exchange, the device is designed around the assumption that its software will be replaced. Seeed Studio points to 4 open-source firmware projects.
Flash Crosspoint and it runs as an e-reader. TRMNL is a project that renders dashboards of assorted information, turning the panel into a single board carrying a clock, weather, and calendar. For a smart home slant, ESPHome or OpenDisplay lets it serve as a display and control endpoint for Home Assistant. There is also a dedicated firmware for Seeed Studio's own SenseCraft HMI, which builds ePaper screens without writing code.
An ESP32-S3 paired with 8 MB of PSRAM, 32 MB of flash, and a microSD slot is generous for a board of this kind. Getting buttons, touch, a microphone, and sensors already fitted inside an enclosure removes the work of designing a case. For buyers who value that more than the polish of the stock app, this is the appeal.
Priced at 49.90 USD, shipping expected in mid-September
The price is 49.90 USD (about 7,900 yen). The first 500 units carried an early-bird price of 39.90 USD (about 6,300 yen), but that window has already closed. Shipping is set to begin in mid-September, and Seeed Studio plans to stock the device on its AliExpress store as well.
Exchange rate: 1 USD = 159 JPY (as of July 31, 2026)
Even among 3.97-inch E Ink devices, this points somewhere different from readers built purely for books or from DIY family calendars. The reTerminal Sticky is a cheap foundation for a panel that shows information wherever you put it, and the idea that you simply swap in different firmware when the default use case does not fit is what the price reflects.
Summary
The reTerminal Sticky combines a 3.97-inch monochrome ePaper panel with an ESP32-S3, a microphone, a temperature and humidity sensor, and a magnet, for 49.90 USD. Alongside stock firmware that writes notes from your voice, buyers can pick from 4 open-source firmware options covering e-reading, dashboards, and Home Assistant integration. The stock app is limited to English and Simplified Chinese for now, but a stick-anywhere E Ink screen for under 10,000 yen is an appealing proposition. Shipping is expected from mid-September.
