-1

It's about the stm32 question ,now I want to compile the program about receiving and sending data through gpio in keils .when I build it ,there are always having some warning about

#223-D: function "usart1_send_byte" declared implicitly or #223-D: function "usart1_send_byte" declared implicitly

I don't know how to define it,please help me .

piyushj
  • 1,546
  • 5
  • 21
  • 29
Ling Liu
  • 1
  • 1
  • You're probably missing a header include, but since STM32 is a hardware product line, not a programming language, who knows? – Notlikethat Jul 21 '16 at 09:33

2 Answers2

0

It is in a header file, probably something similar to stm32f1xx.h, depending on your board. ST has just released an online course through Udemy, very good for beginning the microcontroller journey if you plan to continue with ST chips. Sign up through my.st.com , the forum there is also quite useful.

Etienne Stehelin
  • 1
  • 2
0

If your code compiles/links and works correctly, you have the actual implementation of usart1_send_byte somewhere. Your compiler warns, but linker can still link because it is existing somewhere. Do a file search for usart1_send_byte and find the header file which the function is defined. Then include that header file to the source file that this warning appears.

SamR
  • 384
  • 3
  • 12