Collection of four sketches for creating an e-paper (e-ink) clock or calendar with an Arduino (Uno or Nano) and a Waveshares 2.9” e-paper screen.
All the sketches assume the Arduino is wired as follows:
| DS3231 | Header Wire Colour | Arduino |
|---|---|---|
| SCL | A5 | |
| SDA | A4 | |
| VCC | 5V | |
| GND | GND | |
| SQW | D2, for interrupt alarm, set with wakeUpPin() | |
| Screen | ||
| BUSY | Purple | D7 |
| DC | Green | D8 |
| RST | White | D9 |
| CS | Orange | D10 |
| DIN | Blue | D11 |
| CLK | Yellow | D13 |
| VCC | Grey | 3.3V |
| GND | Brown | GND |
| Arduino GND | D4 (Optional, connect to add 1 hour for daylight savings) |
Requires:
Test the GxEPD2 library for displaying graphics on the e-paper screen. Specifically showing how to use two different fonts on the same display.
See article Arduino E-paper Screen for more details.
Requires:
Use a DS3231 Real Time Clock module’s alarm function, and the low-power library to put the Arduino to sleep, and then wake it again.
See article Arduino & Real-Time Clock for more details.
Requires:
Displays the time, and date, on the e-paper screen, updating every minute. Puts the Arduino to sleep in between.
Use the SetSerial example sketch from the DS3232RTC Library (File -> Examples -> DS3232RTC -> SetSerial).
If you need to adjust between winter and summer time (plus 1 hour) set the time to winter time, then connect GND to pin D4, this will add 1 hour to the displayed time.
Shows the day of the week in large letters across the top, and the date below in a smaller font. Updates daily at midnight, sleeps the Arduino in between.