[Martin Fasani] has set out to build a beautiful low power E-Ink Calendar he can hang on his wall. But perhaps more importantly, the work he has done makes it easier for everyone in the future to have a e-ink display. Many battery-powered e-ink projects connect to some server, download a bitmap image, display the new image, and then go into a deep sleep power mode. [Martin’s] project is no different, but it uses a handy microservice that does the conversion and rendering for you.
The firmware for this ESP32/ESP32S2 based calendar is open sourced on GitHub, with a version based on the Arduino framework as well as the native ESP-IDF framework. One particularly fantastic part of the firmware is a C++ component called CalEPD that drives e-paper displays. CalEPD extends the Adafruit_GFX class and is broken out in a separate repo, making it easy to consume on other projects. Since this supports dozens of different e-paper displays, this simplifies the process of building a calendar with different screens. The firmware includes a Bluetooth setup flow from a smartphone or tablet. This means you can quickly configure how often it wakes up, what it queries, and other important features.
The hardware shown in the demo video has a 7.5″ Waveshare screen with 800 x 400 resolution nestled inside a 3D-printed shell. There is also a 5,000 mAh battery with an ESP32 TinyPICO powering the whole system. The TinyPICO was picked for its incredible deep sleep power consumption. All this fits into a frame just 11 mm thick, for which STL files are available. [Martin] continues to work on this calendar display and has recently added support for FocalTech touch panel controllers. We’re excited to see where he takes it next!
This isn’t the first e-ink display project we’ve seen but this is a great reference to build your own. If you need another good starting point, this weather display might give you that little bit of inspiration you need.
Wow, very nice..!
I wish I had such a big screen for my recent similar project : https://trandi.wordpress.com/2020/10/07/epaper-calendar/
Small isn’t a bad thing. Add a battery to your project and a magnet on the back and it would be the perfect fridge family calendar / shopping list.
Not sure if you’ve checked the project page, but it does have both a battery and a magnet…:)
I just had the same idea yesterday, so I contacted E-Ink to see what would be good to use. They said a Matrix display. I will have to look it up on their website. The goal here would be to show the family activities on a display that you could send messages to, from your cellphone. I am not an expert in programming, I just have ideas and ask people if it interests them. I would prefer double-sided tape to fix it to the fridge though. Would a small solar panel eliminate the need to change the battery ?
Great looking project. I build a similar personal calendar(https://www.davidhampgonsalves.com/life-dashboard/) using a hacked kindle and some cross-compiled rust. Second hand kindles are a great source of e-ink displays if you don’t mind using the processor it comes with and if you get a generation that has a working RTC.