Arduino Board:

Arduino Uno R3

Arduino Leonardo

Microcontroller:

ATmega328P

ATmega32U4

Clock:

16 MHz resonator

16 MHz crystal

User I/O lines:

20

23

PWM outputs:

6

7

Analog inputs:

6

12

Ground access points:

4

4

User LEDs:

3

3

User pushbuttons:

—

—

Reset button:

Power switch:

Buzzer option:

microSD option:

LCD option:

Arduino-compatible
bootloader:

USB connector:

B

Micro-B

USB/regulator
power selection:

partial

partial

High-performance
reverse-voltage
protection:

Recommended
input voltage:

7 V to 12 V

7 V to 12 V

Regulator type (5 V):

linear

linear

Available
5 V
output
current:

at 3 V in

—

—

at 5 V in

—

—

at 7 V in

1.0 A

1.0 A

at 9 V in

0.5 A

0.5 A

at 11 V in

0.35 A

0.35 A

at 24 V in

—

—

via USB
connector

0.5 A⁽¹⁾

0.5 A⁽¹⁾

Weight:

28 g

20 g