What is Arduino Pro Mini?

Nowadays electronic devices are becoming compact, flexible, and cheap that are capable of doing more functions as compared to their predecessors. A Microcontroller was introduced as a new innovation in the electronics industry. Designed with the purpose of making our tasks easier, with minimum effort, and giving maximum output. Here, we are going to discuss one of the popular microcontrollers Arduino Pro Mini what is this about, the main features, working, technical specifications, and everything you need to know.


The Arduino Pro Mini is a microcontroller board based on the ATmega328.  It contains 14 digital input/output pins (six of which are PWM outputs), six analogue inputs, an on-board resonator, a reset button, and mounting holes for pin headers. To give USB power and communication to the board, a six pin header can be linked to an FTDI cable. The USB connector and built-in programmer have been removed from the Arduino Pro Mini in order to minimize its size, thus after uploading code, you may just place it in your application(which is why it’s also known as application-type).

The Arduino Pro Mini is intended for semi-permanent installation in objects or exhibitions. The board is shipped without pre-installed headers, allowing for the use of a variety of connections or direct wire soldering. The Arduino Mini is compatible with the pin layout.

  • Depending on operating voltage, Arduino Pro Mini is of two types:
    1. Operating Voltage: 5.0V, Crystal Oscillator: 16MHz, Voltage Regulator: KB33.
    2. Operating Voltage: 3.3V, Crystal Oscillator: 8MHz, Voltage Regulator: KB50.
  • Arduino Pro Mini comes with 3 types of built-in memories:
    1. Flash Memory of 32KB out of which 0.5KB is used by the bootloader code.
    2. SRAM of 2KB.
    3. EEPROM of 1KB.

The RAW pin is a new pin on the Arduino Pro mini. The RAW PIN is the on-board regulator’s input. VCC will remain at a consistent value if you attach up to 12V to the RAW pin. Advanced users appreciate this Arduino board because of its flexibility and tiny size.


  • ATmega328 running at 16MHz with external resonator (0.5% tolerance)
  • 0.8mm Thin PCB
  • USB connection off board
  • Supports auto-reset
  • 5V regulator
  • Max 150mA output
  • Over-current protected
  • Weighs less than 2 grams
  • DC input: 5V up to 12V
  • Onboard Power and Status LEDs
  • Analog Pins: 8
  • Digital I/Os: 14
  • Dimensions: 0.7×1.3″ (18x33mm)

Pinout of Arduino Pro Mini

Arduino Pro Mini Power Pins

  • Vin: This is the Arduino board’s input voltage pin, which is used to provide power from an external source.
  • VCC: The Arduino board’s VCC pin is linked to +5V or +3.3V to provide power to the board.
  • GND: The Arduino board is grounded using this pin on the board.
  • Reset: The microcontroller is reset using this pin on the PCB. It’s for resetting the microcontroller.
  • RAW. This pin is used for supplying raw voltage to the board. You can power connect an external power supply ranging from 5V to 12 V.
  • Reset: The microcontroller is reset using this pin on the PCB. It’s for resetting the microcontroller.

Programming Header Pins

  • Programming Header: FTDI six-pin programmer is connected with these pins and is used to upload programming code on the Pro Mini board.

Arduino Pro Mini I/O Pins

  • Analog Pins: The analogue input ranges from 0 to 5V and is used on pins A0 to A7.
  • Digital Pins: The Arduino board uses pins 2 to 13 as a digital input or output.

Arduino Pro Mini Communication Pins

  • Arduino Pro Mini supports 3 Communication Protocols for the transmission of data with other peripherals i.e. sensors, registers etc. and are named as:
    • Serial Protocol.
    • I2C Protocol.
    • SPI(Serial Peripheral Interface) Protocol.
  • TXD & RXD Pins: These pins are used for serial communication. TXD represents the transmission of serial data while RXD is used for receiving the data. Code is also uploaded through Serial Protocol.
  • SPI Pins: Four pins 10(SS), 11(MOSI), 12(MISO), and 13(SCK) are used for communicating through SPI Protocol.
  • I2C Pins: Two Pins(A4 and A5) are used for developing I2C communication. A4 is known as serial data line (SDA) which holds the data and A5 shows serial clock line (SCL) which provides data synchronization clock


Other Pinouts

  • External Interrupt Pins: This pin on the Arduino board is used to generate an external interrupt, and pins 4 and 5 are utilised to do so.
  • PWM Pins: This pin on the board is used to change the width of the pulse to convert a digital signal to an analogue signal. A PWM pin is one with the numerals 3, 5, 6, 9, 10, and 12.


All the ARDUINO boards are popular because of ease of understanding and application. Furthermore, the ARDUINO is an open source platform from which all relevant data and original module schematics can be obtained. This platform allows users to personalise the system to meet their own needs. There are few cases where PRO MINI is chosen over other Arduino boards:

Case 1: When the system is installed permanently. The board just needs to be programmed once in permanent applications, and that’s all. In such instances, features such as USB programmers, I/O ports, and other supporting devices are rendered unusable. The PRO MINI was created with such systems in mind. This board just includes basic hardware, which is sufficient for such purposes.

Case2:  This is one of the ARDUINO’s tiniest boards. It can be employed in mobile apps because to its convenient size..

Case3: The cost of the board is significantly lower when using basic hardware.

Case4: The PRO MINI’s 32Kbytes of RAM allows it to run most application programmes.

How to Program Arduino Pro Mini:

  • To begin, download and install the Arduino IDE software, which is the official software for programming Arduino boards.
  • Connect the board to the computer using a USB to Serial converter (FTDI serial module) to transmit the programme to the board.
  • Create the programme in C using the IDE software.
  • The code can be burned without the use of a separate burner. You can simply burn the code and transfer it to the board using the IDE programme.
  • After you’ve burned and transferred the programme to the board, you’ll need to power it up so it’ll work with your project.
  • There are two ways to power the board other than utilizing the FTDI serial module. You may use the RAW to power the board by changing the voltage range from 5 to 12 volts. Depending on the board’s version, it will automatically regulate to 3.3V. If your project has a regulated voltage of 3.3V, however, you can connect it directly to the board’s Vcc pin. The board version is KB33, which operates at 3.3V, as opposed to KB50, which operates at 5V.
  • These two methods of powering up the board are handy when the board has been unplugged from the computer and the application has previously been burned using the FTDI module.

Advantages & Disadvantages of Arduino Pro Mini


  • This pro-mini is particularly designed so that you can permanently embed it in your project.                          
  • Due to its favorable form factor, its power consumption is very low.
  • It can be put into a portable device due to its smaller size.
  • It is very light in weight.
  • Slower speed allows better controllability.
  • Cost-effective.


  • It does not have any USB port and other connectors.
  • It does not have an inbuilt programmer.


  • Hobby projects.
  • Power supply systems.
  • IoT applications.
  • Display systems.
  • Instrumentation.

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