Arduino Pro Mini Pinouts

Arduino Pro Mini Pinouts

There are many boards claiming to be Arduino Pro Mini's or clones of the Arduino Pro Mini. Unfortunately, the pinouts are different for about every one. There are two pinouts for the Pro Mini that I am aware of. All are from Sparkfun. First is the original Arduino Pro Mini.

Sparkfun Arduino Pro Mini

This is the real deal. There are 8 analog inputs and 14 digital I/O. It comes in 5V/16MHz and 3.3V/8MHz versions. The additional analog inputs, pins A4 - A7 are on the inner pins, which are staggered 0.05" off from the main pins, and won't fit on a prototype board. In the picture, A4 is at the top of the four inner pins and A7 is at the bottom.

Sparkfun Protosnap - Pro Mini

There are only 6 analog inputs on the Protosnap Pro Mini. It is otherwise identical to the Arduino Pro Mini. A4 and A5 are present in the two inner pins, but A6 and A7 are missing.

These two images were lifted from Sparkfun and are CC BY-NC-SA 3.0. The Sparkfun Protosnap image was rotated to allow comparison between the pinouts.

The reason it is not very handy to have a Pro Mini pinout is because if the Pro Mini you have is not from Sparkfun, it is either a clone, a kind-of-like, or a counterfeit. In almost all cases, even the counterfeits, the pinouts are different. Many have the programming header pinout backwards, or put pins on the end of the board, which in the real Arduino Pro Mini has no pins. The boards are after all intended to be plugged into a breadboard. At least without the A4 - A7 pins in place.

Images from Sparkfun Electronics
Arduino Board Logo


Arduino-Board is the go-to source for information on many available Arduino and Arduino-like boards, tutorials and projects.

Help and Support


Stay updated

Sign up if you would like to receive our once monthly newsletter.