Arduino/libraries/DS3232RTC/DS3232RTC.cpp: In static member function 'static byte DS3232RTC::read(tmElements_t&)':
Arduino/libraries/DS3232RTC/DS3232RTC.cpp:112:51: error: '_BV' was not declared in this scope
tm.Second = bcd2dec(i2cRead() & ~_BV(DS1307_CH));
^