This Arduino library, is a display like driver based on the Adafruit_GFX library to drive the Charlieplex display on the Arduino UNO R4 WiFi boards. This is an alternative to the library ...
The DCF77 receiver is connected to digital pin 15. The sketch attaches an interrupt to measure the length of the pulses. A 0.1 sec pulse is binary 0, a 0.2 sec pulse is binary 1. One pulse per second, ...