Home - Blog

Arduino Pro Mini vs Nano – A Comprehensive Comparison

The Arduino board is one of the most popular microcontrollers due to its versatility. Often, many people opt for the Arduino Uno, but where fitting in a small size is necessary, this version is not feasible. Instead, Arduino Pro Mini vs Nano is a handy alternative. 

We’ll explore the features of these two at length.   

Pin Descriptions of Arduino pro mini vs. nano

A car robot toy made using an Arduino board

Fig 1: A car robot toy made using an Arduino board

Arduino Pro Mini Pinout

The microcontroller features 14 digital input/output pins whose functions are as follows: 

  1. Pin 0 and Pin 1 are UART pins/ serial pins for serial communication or receiving and transmitting TTL serial data, respectively. 
  2. Next, we have Pin 2 and 3 that function as external interrupts. Triggering these pins prompts an interrupt. 
  3. We have Pins 3, 5, 6, 9, 10, and 11. You use these pins with the analogWrite function to give an 8-bit PWM output. 
  4. Also, there is Pin 10 (Slave Select), Pin 11 (Master Output/ Slave Input), Pin 12 (Master Input/ Slave Output), and Pin 13 (Serial Clock). These are imperative in supporting SPI communication. 
  5. Further, we have Pin 13, which features a built-in LED. The LED goes on when the pin is high and off when the pin is low. 
  6. In addition, there’s Pin I2C which enables I2C communication. 
  7. Moreover, we have the Data Terminal Ready (DTR) pin for resetting the board and inputting the bootloader for the Arduino pro mini programming
  8. Lastly, there’s a RESET pin for setting the microcontroller. 

Arduino Nano Pinout

Pin TypePin Function
Power pins – Vin, 3.3V, 5V, GNDVin is the input voltage pin connecting to an external power source of 7V to 12V. Next, we have the 5V for supplying a regulated power supply voltage. Also, there’s the 3.3V pin that receives minimum voltage from the voltage regulator. Lastly, GND is the board’s, Ground Pin.
Reset Pin/ Reset Button.It is useful in resetting the microcontroller.
Pins A0 to A7 or Analog Voltage Pins.They maintain the board’s analog input voltage between 0V and 5V. 
Pins D0 to D13/ I/O Pins.These are the digital pins. 
Serial Communication Pins (RX and TX).They are useful in receiving and transmission of the board’s TTL serial data.
Pin 2 and Pin 3 (External Interrupts). These are essential in initiating an interrupt
Pins 3, 5, 6, 9, and 11 (PWM Pins).The pins support 8-bit PWM output.
Pins 10,11,12 and 13.They provide SPI communication support. 
Pin 13 (Inbuilt LED) It switches the LED ON and OFF depending on the board’s condition. 
AREFIt provides a reference voltage to the board
Pin A4 and A5.They support TWI communication. 

What are the Differences between Arduino Pro Mini vs Nano?

Both boards are useful in DIY projects

Fig 2: Both boards are useful in DIY projects

Features Arduino NanoArduino Mini
Processor ATMega328P microcontrollerATMega328P and ATMega168P microcontroller
Input/Operating voltageOperating Voltage- 7V to 9VInput Voltage- 5VSame as Arduino Nano
Speed of CPU16 MHz processor speed 16 MHz processor speed
Input/Output AnalogAnalog Input pins count – 6 No analog output Pins Analog Input count- 8 No analog output pins
Digital IO/PWMTotal Pins- 14PWM Pins- 6Total Pins- 14PWM Pins- 6
SRAM (KB)2 KB1 KB and 2 KB
Flash32 KB internal flash memory16 KB and 32 KB internal flash memory
USB SupportHas a USB support (Micro-USB Connector), and FTDI forms the USB connectionIt lacks an external USB connection

Which Arduino Board is Better?

Fig 3: An Arduino board sketch

Both boards run on Arduino software and thus can perform in equal measure. However, the Nano is better for applications requiring fitting in a solderless breadboard since it’s small and has other additional features.

Moreover, the NANO has superior RAM to the Micro version. But, for less advanced projects, you can settle for the pro mini. 


The above boards are useful for advanced users and simple DIY projects. We hope that we have explicitly covered the two modules. However, for further queries, communicate with us

Avatar photo
Emma Lu
Our professional engineering support saves our customers a lot of trouble and loss. >>>>>> After you place the order, our engineer will conduct technical reviews to make sure the parts can be mounted well/correctly on the boards. We will check if the component packages match well with the Gerber footprints, if the part numbers you provided match well with the descriptions, and if the polarity is clearly marked. >>>>> When your design is ready, please send your Gerber and BOM so we can quote and start!