E-ink displays are becoming almost common in DIY electronics circles, and now we have very capable, low-power microcontrollers, some of which feature some sort of wireless connectivity. Combine these two, and you have the potential for a basic information screen — a low-power device that always displays some sort of relevant information, whether it’s the date or the weather.
For their Hackaday Prize entry, [Wenting] and [Dong] are building an e-ink calendar. It’s a calendar, it displays bitmaps, it can display the time, and with a little more hacking it can display the weather, current traffic, or train schedule. If this were the 90s, we would have called this an information appliance, and it would have blown everyone’s minds.
The current design of this e-ink calendar uses an 800 x 600 pixel display working in 16-level grayscale mode. The processor is an STM32F4, and in a cost-reducing revision, an external SRAM was thrown out and the frame buffer was moved to the internal RAM. The e-ink display is actually pretty quick, allowing for greater than 10 FPS in 1-bit mode.
As with any e-ink project, driving the display is a minor nightmare, but [Wenting] is able to push a few frames per second to the display. That’s good enough for a device that shouldn’t actually change all that much — this is a calendar, after all.