keil5调试usmart HAL实验时，出现多条找不到.h文件的错误。
..\..\Middlewares\USMART\usmart_port.c(45): error: #5: cannot open source input file "./USMART/usmart.h": No such file or directory
#include "./USMART/usmart.h"
..\..\Middlewares\USMART\usmart_port.c: 0 warnings, 1 error
compiling usmart_config.c...
..\..\Middlewares\USMART\usmart_config.c(1): error: #5: cannot open source input file "./USMART/usmart.h": No such file or directory
#include "./USMART/usmart.h"
..\..\Middlewares\USMART\usmart_config.c: 0 warnings, 1 error
compiling usmart_str.c...
..\..\Middlewares\USMART\usmart_str.c(50): error: #5: cannot open source input file "./USMART/usmart.h": No such file or directory
#include "./USMART/usmart.h"
..\..\Middlewares\USMART\usmart_str.c: 0 warnings, 1 error
compiling stm32f1xx_hal_tim_ex.c...
"..\..\Output\atk_f103.axf" - 5 Error(s), 0 Warning(s).
解决办法如下：
