It’s not that unusual to have ADC offsets. Sometimes vendor code hides it (PSoC), sometimes it’s in full view of everyone (ESP32). Sometimes you just have to do something tricky like running ...

(Hint: there’s no Arduino-provided code involved; hardware registers and the __asm keyword show up.) If you learned embedded programming in an earlier era, this will probably seem glaringly obvious.

Arduino's language is based on C++, which is one of the most popular programming languages used by developers today. C++ is geared towards larger apps and is responsible for some of the code ...