Arduino Pro Micro
A: Official version
Microcontroller: ATmega328P
Serial Interface Chip: ATMEGA16U2-MU

CARACTERISTICAS

Microcontroller ATmega328 *
Board Power Supply: 3.35 -12 V (3.3V model) or 5 - 12 V (5V model)

Circuit Operating Voltage: 3.3V or 5V (depending on model)
Digital I/O Pins 14
PWM Pins 6
UART 1
SPI 1
I2C 1
Analog Input Pins 6
External Interrupts 2
DC Current per I/O Pin 40 mA
Flash Memory 32KB of which 2 KB used by bootloader *
SRAM 2 KB *
EEPROM 1 KB *
Clock Speed 8 MHz (3.3V versions) or 16 MHz (5V versions)