
PE6 (INT6/AIN0)
1
UVcc
2
D-
3
D+
4
U
G
n
d
5
UCap
6
VBus
7
PB0 (SS/PCINT0)
8
PB1 (PCINT1/SCK)
9
PB2 (PDI/MOSI/PCINT2)
10
PB3 (PDO/MISO/PCINT3)
11
PB7 (OC0A/OC1C/PCINT7/RTS)
12
RESET
13
VCC
14
G
N
D
1
5
XTAL2
16
XTAL1
17
PD0 (INT0/SCL/OC0B)
18
PD1 (INT1/SDA)
19
PD2 (INT2/RXD1)
20
PD3 (INT3/TXD1)
21
PD5 (XCK1/CTS)
22
G
N
D
2
3
AVCC
24
PD4 (ICP1/ADC8)
25
PD6 (T1/OC4D/ADC9
26
PD7 (T0/OC4D/ADC10)
27
PB4 (PCINT4/ADC11)
28
PB5 (OC1A/OC4B/PCINT5/ADC12)
29
PB6 (OC1B/OC4B/PCINT6/ADC13)
30
PC6 (OC3A/OC4A)
31
PC7 (ICP3/CLK0/OC4A)
32
PE2 (HWB)
33
VCC
34
G
N
D
3
5
PF7 (ADC7/TDI)
36
PF6 (ADC6/TDO)
37
PF5 (ADC5/TMS)
38
PF4 (ADC4/TCK)
39
PF1 (ADC1)
40
PF0 (ADC0)
41
AREF
42
G
N
D
4
3
AVCC
44
P
A
D
4
5
ATmega32U4
1 uF
C3
VCC
L1
10 uH
0.1 uF
C5
AVCC
VCC
AVCC
VBUS
22
R2
22
R1
nRESET
MISO
MOSI
SCK
TXLED
D8
D9
D10
D11
D3
D2
D0
D1
D4
D12
D6
D7
D5
D13
A0
A1
AREF
D-
D+
D+R
D-R
HWB
A2
A3
A4
A5
RXLED
Y1
16 MHz
10 pF
C1
10 pF
C2
XTAL1
XTAL2
AVR3V3
VBUS
1
D-
2
D+
3
ID
4
GND
5
N
C
6
N
C
7
N
C
8
N
C
9
N
C
1
0
N
C
11
USB Micro-B
VCC
0.1 uF
C31
0.1 uF
C25
0.1 uF
C32
SW1
A-Star 32U4 Prime LV
©
2019 Pololu Corporation
www.pololu.com
Schematic diagram
Primary microcontroller connections
Page 1 of 6
R
0.1 uF
C4