錯誤解決分享.\objects\project_l.axf: Error:L6218E:Undefined symbol data (refe...

.\objects\project_l.axf: Error:L6218E:Undefined symbol data (referred from main.o)，
.\Objects\project_1.axf: Error: L6218E: Undefined symbol g_usart3_buf (referred from main.o).
.lObjects\project_1.axf: Error: L6218E: Undefined symbol g_usart3_event (xeferred from main.o)
.Not enough information to list image symbols.
Not enough information to list load addresses in the image map.Finished: 2 information

錯誤解決，先在函數文件中定義初始化變量，再到H文件中extern，再到主C文件包含.文件就可以了