Pololu 3pi Robot - Manual (Page 46)

Pin Assignment Table Sorted by Pin
ATmegaxx8
Pin
3pi Function Notes/Alternate Functions
PD0 free digital I/O USART input pin (RXD)
PD1 free digital I/O
connected to red user LED (high turns LED on)
USART output pin (TXD)
PD2 LCD control line RS external interrupt 0 (INT0)
PD3 M2 control line Timer2 PWM output B (OC2B)
PD4 LCD control line E
USART external clock input/output (XCK)
Timer0 external counter (T0)
PD5 M1 control line Timer0 PWM output B (OC0B)
PD6 M1 control line Timer0 PWM output A (OC0A)
PD7 LCD data line DB7 connected to green user LED (high turns LED on)
PB0 LCD control line R/W
Timer1 input capture (ICP1)
divided system clock output (CLK0)
PB1 LCD data line DB4
user pushbutton (pressing pulls pin low)
Timer1 PWM output A (OC1A)
PB2 buzzer Timer1 PWM output B (OC1B)
PB3 M2 control line
Timer2 PWM output A (OC2A)
ISP programming line
PB4 LCD data line DB5
user pushbutton (pressing pulls pin low)
Caution: also an ISP programming line
PB5 LCD data line DB6
user pushbutton (pressing pulls pin low)
Caution: also an ISP programming line
PC0
QTR-RC reflectance
sensor (drive high for 10 us, then wait for line input to go low) sensor labeled PC0
(leftmost sensor)
PC1
QTR-RC reflectance
sensor
(drive high for 10 us, then wait for line input to go low) sensor labeled PC1
PC2
QTR-RC reflectance
sensor (drive high for 10 us, then wait for line input to go low) sensor labeled PC2 (center
sensor)
PC3
QTR-RC reflectance
sensor
(drive high for 10 us, then wait for line input to go low) sensor labeled PC3
PC4
QTR-RC reflectance
sensor (drive high for 10 us, then wait for line input to go low) sensor labeled PC4
(rightmost sensor)
PC5
analog input and digital
I/O jumpered to sensors’ IR LEDs (driving low turns off emitters)
ADC input channel 5 (ADC5)
ADC6 dedicated analog input jumpered to 2/3rds of battery voltage ADC input channel 6 (ADC6)
ADC7 dedicated analog input jumpered to user trimmer potentiometer ADC input channel 7 (ADC7)
reset reset pushbutton internally pulled high; active low digital I/O disabled by default
Pololu 3pi Robot User's Guide © 2001–2014 Pololu Corporation
9. Pin Assignment Tables Page 46 of 63