Boards
Compare Uno R3, classic Nano V3, Mega 2560, Leonardo, Micro, and Pro Mini references: pinouts, memory, upload settings, and simulation support.
ATMEGA328P
Arduino Uno R3
A familiar starting point for code and supported simulation.
32,256 B application flash
2,048 B SRAM · 6 analog inputs
ATMEGA328P
Arduino Nano V3
The classic compact AVR board, with old and new bootloader profiles.
30,720 B application flash
2,048 B SRAM · 8 analog inputs
ATMEGA2560
Arduino Mega 2560
More I/O, memory, and UARTs. Compile/upload target; no Mega simulation.
253,952 B application flash
8,192 B SRAM · 16 analog inputs
ATMEGA32U4
Arduino Leonardo
Serial is native USB; Serial1 is TTL UART on D0/RX and D1/TX. I2C uses D2/SDA and D3/SCL. SPI uses the ICSP header (Micro also exposes named SPI pins). Upload resets/re-enumerates USB; hardware validation is pending.
28,672 B application flash
2,560 B SRAM · 12 analog inputs
ATMEGA32U4
Arduino Micro
Serial is native USB; Serial1 is TTL UART on D0/RX and D1/TX. I2C uses D2/SDA and D3/SCL. SPI uses the ICSP header (Micro also exposes named SPI pins). Upload resets/re-enumerates USB; hardware validation is pending.
28,672 B application flash
2,560 B SRAM · 12 analog inputs
ATMEGA328P
Arduino Pro Mini
Requires a compatible USB-to-serial adapter with matching logic voltage and DTR reset (or manual Reset). A6/A7 are analog-only. Hardware upload validation is pending.
30,720 B application flash
2,048 B SRAM · 8 analog inputs