[Risolto]Definire variabili locali una sola volta

[uwefed]

https://www.arduino.cc/reference/en/language/variables/variable-scope--qualifiers/scope/
https://www.arduino.cc/reference/en/language/variables/variable-scope--qualifiers/static/
https://www.arduino.cc/reference/en/language/variables/variable-scope--qualifiers/volatile/
https://www.arduino.cc/reference/en/language/variables/variable-scope--qualifiers/const/