Upload timeout – avrdude: stk500v2_getsync(): timeout communicating with programmer
This error will occur if the TX1 or RX1 pins are being driven by something else, blocking the programming comms. If you are using UART0 for something which is driving the RX pin then disconnect it to allow programming to occur.
‘Wire’ was not declared in this scope
If you are using libraries like Wire in your own .c files or library then you need to include Wire.h both in your library (where you’re using the things it defines) and in your main sketch (which tells the IDE to include its folder in the search path for includes during compilation and to link in its .c / .cpp files).
request for member in something not a structure or union
Is your file names .c instead of .cpp and you are including a c++ library or some other c++ thing in it?