I just got an Arduino micro clone and want to know the pin mapping from ATMEGA32U4 to Arduino pins. Ultimately I want to make my own board using the ATMEGA32U4. Here is a pin correspondence I made:
I read from Doc7766 that there are 26 GPIO lines on this chip. I only counted 24 pins have been assigned various Arduino pin names. (Oops, forgot to increment D24 to D28 but no worries they are duplicates)
I also listed the two pins that are not mapped into Arduino pins, PD5 and PE2. I know PE2 has special function to enable bootloader at reset. So I'm not going to mess with this pin. But what about PD5 that is used to simply turn on/off a TX led, which is CTX_bar pin. I wonder if there is any easy way to give this pin an Arduino pin name and not use the extended USART mode. Maybe not worth the trouble just for one pin.
What about SS/RXLED? Am I able to use this pin to do chip select for an SD card or is it not able to do it due to some arduino set up? I really want to use this pin. I'm short on pins for the project. Thanks.