[Error] 'buff' undeclared (first use in this function)
[Error] 'devUART4' undeclared (first use in this function)
明明都有被调用可他还是显示未在该函数中首次使用
[Error] 'buff' undeclared (first use in this function)
[Error] 'devUART4' undeclared (first use in this function)