Loading source-backed pinouts…
Microcontroller
Arduino Micro
A breadboard-friendly ATmega32U4 board developed with Adafruit, bringing Leonardo-style native USB to a compact dual-row module.
Processor
Microchip ATmega32U4
Logic
5 V operating voltage
Power
Micro-USB, VIN, 5 V pin
Format
Breadboard module
Check before wiring
- I2C is on D2/D3; do not assume Nano-style A4/A5 I2C.
- Digital IO is 5 V; level-shift 3.3 V-only hardware.
- VIN range and current limits differ from many Micro-compatible clones.
- SPI appears on D14-D16 and ICSP; check shield or carrier wiring before reuse.
Interfaces
GPIOI2CSPIUARTADCPWMUSBJTAG
Source-backed connector
Interactive pin map
Pin map
Connector
Arduino Micro breadboard headers and ICSP
Signals grouped by function — schematic layout, not to physical scale
Dense header — open Full view for a roomier, fully-labelled diagram.
Simplified diagram, grouped by function — not to physical scale. Pin data is source-backed; verify against the linked documentation.
Hover, tap, or focus a pad to inspect a pin. Use arrow keys to move between pins.
- Official Arduino Micro full pinout maps the ATmega32U4 to breadboard headers plus ICSP.
- I2C is on D2/D3; SPI is available on D14-D16 and the ICSP header.
- Digital IO is 5 V logic; the 3.3 V output rail is limited to 50 mA.
- VIN is specified as a 6-9 V board input in Arduino's pinout PDF.
All 37 pins (table)
| # | Signal | Role | Net | Also / notes |
|---|---|---|---|---|
| Digital / communication | ||||
| 1 | UART | UART | PD2 / RXD1 | |
| 2 | UART | UART | PD3 / TXD1 | |
| 3 | I2C | I2C | PD1 | |
| 4 | I2C | I2C | PD0 / PWM | |
| 5 | ADC | PD4 | ||
| 6 | PWM | PC6 | ||
| 7 | ADC | PD7 / PWM | ||
| 8 | GPIO | PE6 | ||
| 9 | ADC | PB4 | ||
| 10 | ADC | PB5 / PWM | ||
| 11 | ADC | PB6 / PWM | ||
| 12 | PWM | PB7 | ||
| 13 | ADC | PD6 | ||
| 14 | PWM | PC7 | ||
| 15 | SPI | SPI | PB3 / MISO | |
| 16 | SPI | SPI | PB1 | |
| 17 | SPI | SPI | PB2 / MOSI | |
| 18 | SPI | SPI | PB0 | |
| Analog / power | ||||
| 18 | ADC | PF7 | ||
| 19 | ADC | PF6 | ||
| 20 | ADC | PF5 | ||
| 21 | ADC | PF4 | ||
| 22 | ADC | PF1 | ||
| 23 | ADC | PF0 | ||
| 24 | Power | AREF | ||
| 25 | Power | 3V3 | ||
| 26 | Power | 5V | ||
| 27 | System | |||
| 28 | Ground | GND | ||
| 29 | Power | VIN | ||
| 30 | Reserved | |||
| ICSP | ||||
| 1 | SPI | SPI | PB3 / MISO | |
| 2 | Power | 5V | ||
| 3 | SPI | SPI | PB1 | |
| 4 | SPI | SPI | PB2 / MOSI | |
| 5 | System | |||
| 6 | Ground | GND | ||
Why it matters
- Native USB supports serial, keyboard, and mouse applications.
- Official full pinout PDF documents D14-D17 SPI labels and ATmega32U4 ports.
- Compact module fits solderless breadboards more easily than a shield-format Leonardo.
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