ATmega32U4
pin name
Arduino
pin names
Zumo 32U4 functions
Notes/alternate functions
PB6
10, A10, 28 Left motor PWM
Analog input (ADC13)
Timer1 PWM output B (OC1B)
Timer4 PWM output B (OC4B)
Pin-change interrupt (PCINT6)
PB2
16, MOSI
Left motor direction
SPI Master Output/Slave Input (MOSI)
Pin-change interrupt (PCINT2)
PB5
9, A9, 27
Right motor PWM
Analog input (ADC12)
Timer1 PWM output A (OC1A)
Timer4 PWM output B (OC4B)
Pin-change interrupt (PCINT5)
PB1
15, SCK
Right motor direction
SPI Clock (SCK)
Pin-change interrupt (PCINT1)
PB4
8, A8, 26
Left encoder XORed input
Analog input (ADC11)
Pin-change interrupt (PCINT4)
PE2
-
Left encoder input
Hardware bootloader select (HWB)
PE6
7
Right encoder XORed input
Analog comparator negative input (AIN0)
External interrupt source (INT6)
PF0
A5, 23
Right encoder input
Analog input (ADC0)
PD0
3, SCL
I²C clock for inertial sensors
Timer0 PWM output B (OC0B)
External interrupt source (INT0)
PD1
2, SDA
I²C data for inertial sensors
External interrupt source (INT1)
RESET
-
Reset pushbutton
internally pulled high, active low
AREF
-
-
Analog reference
3.11. Adding electronics
This section gives tips for how the Zumo 32U4 can be expanded with additional electronics.
Freeing up I/O pins
If you want your additional electronics to send or receive information from the AVR, you will need to connect it
to one or more of the AVR’s I/O pins. Each I/O pin is already being used for some other purpose, as documented
in
Section 3.10
, so you might need to disable or disconnect one of the other features of the Zumo 32U4.
If are not using the proximity sensors and you do not care about turning off the infrared emitters for the line
sensors, you can cut the surface-mount jumper on the front sensor array labeled “LED”. This frees pin 11 (PB7)
for other uses. Pin 11 can be used for digital I/O and analog input. We do not recommend making this change if
you are using the proximity sensors, because then the line sensor infrared emitters would always be on, which
would interfere with the proximity sensors.
Pololu Zumo 32U4 Robot User’s Guide
© 2001–2015 Pololu Corporation
3. The Zumo 32U4 in detail
Page 28 of 76
