based on https://github.com/schreibfaul1/ESP8266-LED-Matrix-Clock and https://www.instructables.com/id/ESP8266-LED-Matrix-Clock/
first article: https://nicuflorica.blogspot.com/2019/02/ceas-matriceal-animat-cu-esp8266-si-rtc.html
second article: https://nicuflorica.blogspot.com/2019/02/ceas-matriceal-animat-si-termometru-cu.html