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Yes—you can turn a tiny e-reader into a glanceable calendar display, but this particular build is more than a Home Assistant dashboard. It uses an Xteink X4 Classic running modified Crosspoint firmware: Home Assistant supplies calendar data and hosts a generated BMP image, while the reader wakes periodically to download that image and use it as its sleep screen.
How the calendar display works
The build, described by How-To Geek author Adam Davidson, connects three pieces: calendar data in Home Assistant, a Python script that draws an image, and an Xteink X4 Classic modified to fetch that image while asleep. Davidson’s goal was to make the e-reader’s small E-Ink screen “display something useful during my working day.” Read the original project description at How-To Geek.
- Home Assistant provides the calendar information. In the author’s setup, Home Assistant’s calendar features connect to services such as Google Calendar and Outlook through integrations. That does not establish support for every calendar provider; check whether your specific calendar can be made available in your Home Assistant installation.
- A Python script turns calendar data into a screen image. The script runs in Home Assistant, retrieves calendar information, and renders a BMP at the dimensions required by the X4 Classic. The image is regenerated every 15 minutes.
- The modified reader fetches the BMP. The author’s Crosspoint firmware build can transfer books and images through a local browser page, but that standard File Transfer feature is a user-initiated transfer mode, not continuous synchronization. The author modified the firmware so the reader can wake, connect to Wi-Fi, download the Home Assistant-hosted BMP, replace its sleep-screen image, and return to sleep. A menu control enables or disables this calendar-screen behavior.
How fresh is the event on screen?
The image-generation and device-fetch schedules are different. Home Assistant regenerates the BMP every 15 minutes, but the modified e-reader downloads it once an hour. A new calendar event or change can therefore take up to about an hour to reach the display, depending on when it occurs relative to the reader’s next fetch; the 15-minute image refresh does not make the e-reader update every 15 minutes.
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What device the project uses
The build repurposes the Xteink X4 Classic, a pocket e-reader rather than a dedicated desk calendar. Xteink’s product page lists a 4.3-inch, 219-PPI display, 114 × 69 × 4.9 mm dimensions, a weight of 68 g, a 920 mAh battery, 2.4 GHz Wi-Fi, and BMP image support. Those are manufacturer-listed specifications, not measurements from Davidson’s project. The device has no front light or touchscreen. See Xteink’s X4 product page.
#1 Best Overall
- Provide online user manual (examples for Raspberry Pi/Jetson Nano/Arduino/STM32), please check the manual carefully before using!
- This is an E-Ink display module, 4.2inch, 400x300 resolution, with embedded controller, communicating via SPI interface. Due to the advantages like ultra low power consumption, wide viewing angle, clear display without electricity, it is an ideal choice for applications such as shelf label, industrial instrument, and so on.
- No backlight, keeps displaying last content for a long time even when power down
- Ultra low power consumption, basically power is only required for refreshing
- SPI interface, for connecting with controller boards like Raspberry Pi/Arduino/Nucleo, etc. Onboard voltage translator, compatible with 3.3V/5V MCUs
Xteink’s page showed the product as sold out when accessed in 2026, so availability may change. Check the manufacturer’s current listing before planning a build around this model.
What you need to recreate the approach
- An Xteink X4 Classic or another device whose image format, display dimensions, Wi-Fi access, and sleep behavior can support a similar workflow. The described project specifically uses the X4 Classic.
- Home Assistant with the calendar information you want to display available through an integration.
- A Python script that retrieves the relevant calendar data and generates a BMP in the device’s required dimensions.
- A way for the e-reader to access the hosted image. In this project, that required modifying Crosspoint firmware to fetch the file while the device was sleeping.
The published article explains the architecture, but does not provide the Python script or firmware patch, and it does not identify a Crosspoint version. It therefore gives a useful design to adapt, not a complete copy-and-paste build guide. The firmware modification is the key distinction: using the built-in File Transfer page alone does not create an automatic hourly refresh.
Rank #2
- Provide online user manual (examples for Raspberry Pi/Jetson Nano/Arduino/STM32), please check the manual carefully before using!
- This is an E-Ink display module, 1.54inch, 200x200 resolution, with embedded controller, communicating via SPI interface, supports partial refresh.
- Due to the advantages like ultra low power consumption, wide viewing angle, clear display without electricity, it is an ideal choice for applications such as shelf label, industrial instrument, and so on.
- No backlight, keeps displaying last content for a long time even when power down. Ultra low power consumption, basically power is only required for refreshing
- SPI interface, for connecting with controller boards like Raspberry Pi/Arduino/Nucleo, etc. Onboard voltage translator, compatible with 3.3V/5V MCUs
Battery and practical trade-offs
Davidson expects each scheduled fetch to have minimal battery impact because the reader wakes only long enough to connect and download the image. The project does not report a measured battery-life result, so there is no supported runtime estimate for the modified setup.
The Tool Desk
Outbyte Driver Updater FREEScan for outdated or missing drivers - takes under a minuteDriver Scan →Outbyte PC Repair FREERepair Windows errors before they cause bigger problemsFix Now →The approach favors a small, low-profile display and a glanceable next event over rapid updates or a turnkey calendar interface. It also depends on a working Home Assistant calendar integration and custom firmware behavior. The source describes one build, not a comparison against dedicated e-ink calendar products or other e-readers.
Quick Recap
Best Value
- Provide online user manual (examples for Raspberry Pi/Jetson Nano/Arduino/STM32), please check the manual carefully before using!
- This is an E-Ink raw display, 7.5inch, 800×480 resolution, with embedded controller, communicating via SPI interface.
- Due to the advantages like ultra low power consumption, wide viewing angle, clear display without electricity, it is an ideal choice for applications such as shelf label, industrial instrument, and so on.
- No backlight, keeps displaying last content for a long time even when power down
- Ultra low power consumption, basically power is only required for refreshing
Rank #4
- This is 2.13inch E-Ink display HAT V4 with Raspberry Pi 40PIN GPIO extension header, compatible with Raspberry Pi series boards (includes Raspberry Pi 5/4B/3B+/3B/2B/Zero W/WH/Zero 2 W,etc. ) and compatible with Jetson Nano.
- 250x122 resolution, Black and White Two Display colors, with embedded controller, communicating via SPI interface, supports partial refresh.
- No backlight, keeps displaying last content for a long time even when power down. Ultra low power consumption, basically power is only required for refreshing.
- SPI interface, for connecting with controller boards likeArduino/STM32, etc. Onboard voltage translator, compatible with 3.3V / 5V MCUs.
- Comes with Comes with Online Development Resources and Manual (driver board circuit diagram, examples for Raspberry Pi/Jetson Nano/Arduino/STM32). PLEASE READ THE ONLINE INFORMATION CAREFULLY BEFORE USING IT.
Rank #3
- Enjoy a paper-like viewing experience with the 2.13-inch e-paper display. The screen can retain the last displayed image even after power is removed, making it ideal for applications requiring long-term information display without continuous power supply.
- Designed for low-power projects, this e-ink module only consumes energy during screen updates and remains in standby mode most of the time. Perfect for battery-powered devices, smart labels, IoT projects, and long-running applications.
- Featuring a 250x122 pixel black-and-white display, this e-paper HAT delivers clear text and image rendering. Partial refresh support helps reduce update time and power consumption for smoother display operation.
- Equipped with a standard Raspberry Pi 40-pin GPIO header and SPI communication interface, this display module works with Raspberry Pi series boards, Arduino, ESP32 and other compatible development platforms. Built-in voltage conversion supports both 3.3V and 5V MCUs.
- Comes with connection accessories and supports online resources including driver board diagrams and example programs for Raspberry Pi, Arduino, and ESP32, helping developers quickly start their projects.
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