Keil often commits error handling

1. Hint unresolved EXTERNAL symbol symbol:? C

It is very likely that the corresponding code forgot to join the code group.

2, has been prompted me to repeat the definition of functions, search the Internet, it seems that only the variables of the repeated definition of the problem ah, how the function also has a duplicate definition of the problem ... Finally delete the uart.c and uart.h, and then compile the success ...

Finally look carefully, unexpectedly main.c in the header file contains uart.c

3,error C267: ' xx ': Requires Ansi-style prototype

Xx-is usually a function and lacks a function prototype.
Sometimes oneself clearly has the declaration, this time must notice, may be later slightly changed the incoming parameter or the return type, the notice revises again.

4. warning C276:constant in condition expression

See the wrong place to understand.

5,* * * WARNING l16:uncalled SEGMENT, ignored for OVERLAY PROCESS

Not called fragments, note the difference between the distinguished and the not called functions. WARNING l16:uncalled SEGMENT, ignored for OVERLAY PROCESS
This is usually a constant segment, for example, my Ledchar defines a non-invocation.