Pinouts in area U1 are assigned to the X-Z8350 core. Pinouts in area U2 are assigned to the ATmega32u4 core. Each of the 20 digital pins (A0 - A5, D0 - D13) in area U2 can be used as an input or output, each operating at 5 volts. Each pin can output or receive 40 mA and each has an internal pull-up resistor (disconnected by default) of 20-50k ohm. Caution: Exceeding 40mA on any I/O pin may cause..
