The Arduino-compatible Pro Micro 16MHz/5V is a very little development board (36 x 18 mm). Its size makes it ideal for embedded projects.

It is easly programmable with the Arduino IDE software through an USB connection.


  • Microcontroller: ATmega32U4
  • Clock speed : 16MHz
  • Operating voltage: 5 V (input voltage limit: 6-9 V)
  • Flash Memory: 32 KB (which 4 KB used by bootloader)
  • SRAM: 2,5 KB
  • EEPROM: 1 KB
  • Up to n. 18 I/O Digital PINs
  • Up to n. 9 Analog PINs
  • n. 5 PWM PINs
  • n. 1 UART (serial)
  • n. 1 I2C
  • n. 1 SPI
  • Built-in micro USB connection

PIN function

RAW: regulated voltage input power supply.

VCC: unregulated voltage input power supply.

RST: restart the Pro Micro. This pin is pulled high by a 10K Ohm resistor on the board, so it must be connected to ground to initiate a reset. The Pro Micro will remain “off” until the reset line is pulled back to high.

GND: common ground voltage.

I/O PINs: the n. 18 I/O pins are multitalented. Every pin can be used as a digital input or output, and other pins can be used as an analog input or in PWM mode. These pins are managed in the Arduino IDE application via an integer value between 0 and 21.

PWM: if activated, this pins can be used in the Pulse Width Modulation mode.

UART (serial), I2C, SPI: if activated, this pins can be used in UART, I2C and SPI function mode.

On-board LEDs:
Power (Red LED)
RX, data IN (Yellow LED)
TX, data OUT (Green LED)