STM32芯片不用的GPIO管脚能否不处理？

悬空就行

看内部有没有Pd或Pu，一般都有。没有的，配置成out

Unused I/Os and features All  the  microcontrollers  are  designed  for  a  variety of  applications and  often  a  particular application does  not  use  100%  of  the MCU resources. To  increase the EMC  performance, unused  clocks, counters  or  I/Os,  should  not be left  free,  e.g.  I/Os  should be set  to “0” or “1” (pull-up  or pull-down to the unused  I/O pins.) and unused  features  should be  “frozen”  or disabled.