Arduino Leonardo specs & datasheets
The Uno-shaped Arduino with native USB: its ATmega32U4 can appear to a computer as a keyboard, mouse or game controller.
- Chip / SoC
- Microchip ATmega32U4
- CPU
- 8-bit AVR
- Clock
- 16 MHz
- RAM
- 2.5 KB SRAM
- Flash
- 32 KB (4 KB used by the bootloader)
- I/O voltage
- 5 V
- Released
- 2012
- Status
- In production
Draft entry: these specs were compiled from the linked sources and are waiting for a second check. Spotted a mistake? Use the form at the end of the page.
Specifications
- Chip / SoC
- Microchip ATmega32U4[1]
- CPU
- 8-bit AVR[2]
- Clock
- 16 MHz[1]
- RAM
- 2.5 KB SRAM[2]
- Flash
- 32 KB (4 KB used by the bootloader)[3]
- GPIO
- 20 digital I/O (7 PWM, 12 analog-capable)[1]
- I/O voltage
- 5 V[1]
- USB
- Micro-USB, native on the ATmega32U4[1]
- Upload limits
- 28 KB flash, 2.5 KB RAM[4]
Upload limits are what a sketch or firmware may use after the bootloader, as the build tools enforce them, not the chip’s full memory.
Can I still use it?
- Arduino framework
- Supported[1]Official Arduino core.
As published by each project, checked weekly. A platform not listed has no published information here, which is not the same as no support.
Datasheets and documents
Gotchas
- The serial port re-enumerates. Because USB is handled by the sketch's own chip, the COM port disappears on reset and during upload; `while (!Serial)` waits for the monitor to connect.[1]
- I2C moved to D2/D3. SDA and SCL are on D2 and D3 (and the R3 header pins), not A4/A5 as on the Uno.[1]
- 5 V logic. I/O is 5 V. Sensors and modules that run at 3.3 V (most modern ones) need level shifting on their inputs.[1]
History and use today
History
Released in 2012, the Leonardo dropped the separate USB-serial chip, which made Arduino-based keyboards, macro pads and game controllers trivial.[3]
Still useful for
The Uno-format choice for HID projects; the Micro and SparkFun Pro Micro offer the same chip in breadboard sizes.
Sources
Spotted a mistake?
Every report is read by a person and checked against a source before anything changes. Please link one if you have it.