Arduino MINI 05

The Arduino Mini 05 is a very compact version of the Arduino Nano without an on-board USB to Serial connection

The small version of the Arduino Nano with a breadboard-friendly form factor.


The Arduino Mini is a small microcontroller board originally based on the ATmega168, but now supplied with the 328. (datasheet), intended for use on breadboards and when space is at a premium. It has 14 digital input/output pins (of which 6 can be used as PWM outputs), 8 analog inputs, and a 16 MHz crystal oscillator. It can be programmed with the USB Serial adapter or other USB or RS232 to TTL serial adapter.

The new Mini (revision 05) has a new package for the ATmega328, which enables all components to be on the top of the board. It also has an onboard reset button. The new version has the same pin configuration as revision 04.

Warning: Don't power the Arduino mini with more than 9 volts, or plug the power in backwards: you'll probably kill it.

Arduino Microcontroller





Operating Voltage

5 V

Flash memory

32 KB (of which 2 KB used by bootloader)


2 KB

Clock Speed

16 MHz

Analog I/O Pins

8 (of which 4 are broken out onto pins)


1 KB

DC Current per I/O Pins

40 mA (I/O Pins)


Input Voltage

7-9 V

Digital I/O Pins


PWM Output


Power Consumption

16 mA

PCB Size

18 x 30 mm


2 Kg without headers/ 3 Kg with headers

Product Code

A000087 (with headers) - A000088 (without headers)

Input and Output
Each of the 14 digital pins on the Mini can be used as an input or output. They operate at 5 volts. Each pin can provide or receive a maximum of 40 mA and has an internal pull-up resistor (disconnected by default) of 20-50 kOhms. Pins 3, 5, 6, 9, 10, and 11 can provide PWM output; for details see the analogWrite() function. If anything besides the Mini USB (or other) adapter is connected to pins 0 and 1, it will interfere with the USB communication, preventing new code from being uploaded or other communication with the computer.

The Mini has 8 analog inputs, each of which provide 10 bits of resolution (i.e. 1024 different values). Inputs 0 to 3 are broken out onto pins; input 4 to 7 require soldering into the provided holes. By default the analog inputs measure from ground to 5 volts, though is it possible to change the upper end of their range using the AREF pin and some low-level code.
The Arduino Mini can be programmed with the Arduino software (download).  

To program the Arduino Mini, you will need a USB Serial adapter or other USB or RS232 to TTL serial adapter. 

The ATmega328 on the Arduino Mini comes preburned with a bootloader that allows you to upload new code to it without the use of an in-system-programmer. The bootloader communicates using the original STK500 protocol (reference, C header files).

You can also bypass the bootloader and program the ATmega328 with ICSP (In-Circuit Serial Programming).
Pin Out
Note: the pinout changed from version 03 to version 04 of the Mini, please be sure you use the right diagram.

Arduino Mini 05   Arduino Mini 05
Pin out of the Arduino Mini 03. (older versions are compatible, but missing the IO7 header at the top)

  Pin out of the Arduino Mini 04 and 05. (Note that the ground pin on the left has moved down one pin.)

Schematic & Reference Design

Conformity Declaration


Getting Started

Start with Arduino  or if you want to start playing right away with your board  Start with Arduino MINI 05


If you couldn’t find what you were looking for, please see our Forum Section

You need to download the software and follow this step by step guide.
To program this board need to have Arduino USB 2 Serial Micro
If you have a board that can't load the sketch then try to burn the bootloader.