Modifications

=== Free I/O pins ===

=== Free I/O pins ===

If you want your additional devices to send or receive information from the AVR, you will need to connect them to one or more of the AVR’s I/O pins. The pin assignment table in Section [[lists all of these pins]] and how they are used. Many of the I/O pins are already being used for some other purpose on the board, but there are 8 free I/O pins: 0, 1, 5, 12, A0, A2, A3, and A4. Any of the free I/O lines can be used as basic digital inputs or outputs; each pin also has some special capabilities.

If you want your additional devices to send or receive information from the AVR, you will need to connect them to one or more of the AVR’s I/O pins. The pin assignment table in Section [[Pololu-Romi-32U4-Carte-Broches|lists all of these pins]] and how they are used. Many of the I/O pins are already being used for some other purpose on the board, but there are 8 free I/O pins: 0, 1, 5, 12, A0, A2, A3, and A4. Any of the free I/O lines can be used as basic digital inputs or outputs; each pin also has some special capabilities.

Pin 0 (PD2) and pin 1 (PD3) are the RX and TX lines of the AVR’s TTL serial port.

Pin 0 (PD2) and pin 1 (PD3) are the RX and TX lines of the AVR’s TTL serial port.