Arduino-Compatible Pro Mini ATmega328 Board, 5V 16MHz

The Arduino-compatible Pro Mini 328 is an ultra-compact microcontroller board running an ATmega328 at 5V and 16MHz. Designed for space-constrained projects and wearable electronics, it provides full core functionality in a miniature footprint. It is ideal for intermediate makers, hobbyists and students embedding low-cost processing into permanent builds.

Compact design for custom builds

Measuring just 18x33mm and weighing less than 2 grams, this board is purpose-built for installations where size and weight are critical. It features an SMD layout on a two-layer board to keep dimensions small and production costs low.

I/O pins and layout

The module provides 14 digital input and output pins (with 6 usable as PWM outputs) alongside analog inputs. Analogue pins A4, A5, A6 and A7 are positioned off the edge and clearly labelled on the underside, with unpopulated pin headers included for flexible soldering orientations.

Serial connection and programming

USB communication is handled off-board via a 6-pin FTDI interface to conserve space. It supports auto-reset when connected to an FTDI basic breakout board, and can also be powered and programmed using an FTDI cable.

Power and protection

An on-board 5V voltage regulator supports DC input ranging from 5V up to 12V with a maximum 150mA output. The board is equipped with reverse polarity protection, over-current protection, a reset button, and on-board power and status LEDs.