Arduino #9: Comment déclarer une constante ?

#define ConstNom ConstVal

const Type ConstNom=ConstVal;

const float pi=3.1415926535897932384626433832795;

const float c=3e8; 3x10^8;

const int Vm=220;

#define pi  3.1415926535897932384626433832795

#define c   3e8

#define Vm  220