User`s guide

6. AVR Pin Assignment Table Sorted by Function

Function ATmega324/1284 Pin

free analog input and digital I/O (x8) PA0 – PA7

free digital I/O (x8) PB3, PC0, PC1, PD0 – PD4, PD5**

free digital output PB4*

free PWM outputs (x2) PB3, PB4

red user LED PD1

green user LED PC4

UART0 PD0, PD1

UART1 PD2, PD3

user pushbuttons (bottom to top, x3) PC2, PC3, PC5

motor 1 (direction, speed) PC7, PD7

motor 2 (direction, speed) PC6, PD6

buzzer PD4

LCD control (RS, R/W, E) PB0, PB1, PB2

LCD data (4-bit: DB4 – DB7) PC2 – PC5

SPI auxiliary processor control lines (x3) PB5, PB6, PB7

ICSP programming lines (x3) PB5, PB6, PB7

ADC reference pin AREF

reset pushbutton RESET

*: 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.

**: PD5 is a free digital I/O unless you want to use the built-in servo pulse hardware.

6. AVR Pin Assignment Table Sorted by Function Page 27 of 41