User`s guide

PD0 digital I/O USART0 input pin (RXD0)

PD1 digital I/O

red user LED

(low turns LED on; connection

can be cut and replaced with jumper)

USART0 output pin (TXD0)

PD2 digital I/O

USART1 input pin (RXD1)

External interrupt 0 (INT0)

PD3 digital I/O

USART1 output pin (TXD1)

External interrupt 1 (INT1)

PD4 buzzer Timer1 PWM output B (OC1B)

PD5 digital I/O

servo pulse output (SPWM)

Timer1 PWM output A (OC1A)

PD6 M2 speed control line Timer2 PWM output B (OC2B)

PD7 M1 speed control line Timer2 PWM output A (OC2A)

AREF ADC reference pin

AVCC supply voltage for Port A and ADC not accessible to the user

RESET Reset input reset button (pressing resets MCU)

XTAL1 20 MHz resonator input not accessible to the user

XTAL2 20 MHz resonator input not accessible to the user

*: Using PB4/SS as an input will interfere with communication to the auxiliary processor, so we recommend using

it as a digital output. See Section 6.j of the Pololu USB AVR C/C++ User’s Guide for more information.

7. AVR Pin Assignment Table Sorted by Pin Page 30 of 41