You'd need to do some precision soldering with magnet wire to connect to those pins.
If you do that, you can use MegaCore's "AVR pinout" to use all the pins on the ATmega2560 with standard Arduino I/O functions:
You'd need to do some precision soldering with magnet wire to connect to those pins.
If you do that, you can use MegaCore's "AVR pinout" to use all the pins on the ATmega2560 with standard Arduino I/O functions: