Paul Busby's Compact Magnetic ePaper Calendar Schedules Power-On to Save Battery
Using a real-time clock to wake up on a pre-set schedule, this ePaper calendar maximizes battery life.
Maker Paul Busby has put together a smart ePaper calendar, driven by a Raspberry Pi Zero 2 W single-board computer and a 3D-printed case — taking inspiration for its layout from Microsoft's Outlook client for Apple's iOS.
"I created this project as a way to learn Python and GitHub while building something useful," Busby explains. "The device is magnetically attached to my kitchen fridge. Updates as 6am every morning to show me today's planned events along with as many future events that can fit on the page. Battery percentage is shown in the top right so you know when to recharge and a timestamp of the last successful screen update is shown in the bottom left on the screen."
Busby took inspiration for the build from the MagInkCal project, released late last year — but redesigned it as a more compact display with lower-cost components. "That project uses a much bigger [ePaper] display," Busby explains, "and they are a lot more expensive than the display I have used here."
Inside the 3D-printed housing, which includes magnets to the rear so it can be easily mounted to a metal surface like a fridge or whiteboard, is a Raspberry Pi Zero 2 W single-board computer, a PiSugar2 uninterruptible power supply (UPS) and real-time clock (RTC) board, and a Waveshare 7.5" ePaper display board.
"Through PiSugar2's web interface, the onboard RTC can be set to wake and trigger the RPi to boot up daily at a time of your preference," Busby explains of the device's operation.
"Upon boot, a cronjob on the RPi is triggered to run a Python script that fetches calendar events from Microsoft Calendar for the next few days, and formats them into the desired layout before displaying it on the [ePaper] display. The RPi then shuts down to conserve battery. The calendar remains displayed on the [ePaper] screen, because, well, [ePaper]…"
The full build, including source code and 3D design files for the case, has been published to GitHub under an unspecified open source license.