I needed a device that can store the date of a specific event, which I can check later. To be more precise, I needed a device that can store the last date I fed the flowers. The device must be portable and powered by a battery. And because a whole display only for one date is a bit of a waste, I decided to add more features like weather and calendar widgets.
The obvious choice for the display was E-Paper, and for the IC initially, I picked esp8266, but after comparing it with esp32, I had to switch it.
The esp32 has a feature that is very important for this project – esp_sleep_enable_ext1_wakeup. This allows IC to wake with almost any from the GPIO(here a good tutorial https://randomnerdtutorials.com/esp32-external-wake-up-deep-sleep/).