base info: https://protosupplies.com/product/gy-21-htu21d-humidity-temperature-sensor-module/ and https://surtrtech.com/2020/03/16/sht-21-htu-21-measure-temperature-and-himidity-with-arduino-oled-lcd/
my article: https://nicuflorica.blogspot.com/2023/02/termometruhigrometru-cu-senzor-gy-21-pe.html