… or DS3231 part II 🙂 (see also part III and IV – the story goes on with interrupts)
The next step after testing if it works at all was to display ful time, and especially seconds. So 4 digits offered by TM1637 based module (let’s call it part I) was not enough. I used 8 digits 7 segment display based on MAX7219.
For the code, apart from DS3231 library mentioned in previous post, I used also Eberhard Fahle LedControl library.