How to Use Arduino Pro Mini: Examples, Pinouts, and Specs

The Arduino Pro Mini is a compact microcontroller board designed for embedded applications and prototyping. Manufactured by Mine, this board is based on the ATmega328P microcontroller and is known for its small form factor and low power consumption. It is an excellent choice for projects where space and power efficiency are critical.

• Wearable electronics
• IoT (Internet of Things) devices
• Robotics and automation
• Battery-powered projects
• Prototyping and small-scale production

The Arduino Pro Mini is available in two voltage and frequency variants: 3.3V/8MHz and 5V/16MHz. Below are the key technical details:

The Arduino Pro Mini has a total of 24 pins, including power, analog, and digital pins. Below is the pinout description:

1. Powering the Board:
   • Use the RAW pin for unregulated input voltage (up to 12V).
   • Alternatively, supply regulated 3.3V or 5V to the VCC pin, depending on the board variant.
2. Programming the Board:
   • The Arduino Pro Mini does not have a built-in USB interface. Use an external USB-to-Serial adapter (e.g., FTDI adapter) to upload code.
   • Connect the adapter to the TX, RX, VCC, and GND pins. Ensure the voltage level of the adapter matches the board variant.
3. Connecting Components:
   • Use the digital and analog pins to connect sensors, actuators, and other peripherals.
   • For PWM control, use pins D3, D5, D6, D9, D10, or D11.

• Voltage Compatibility: Ensure that all connected components operate at the same voltage level as the board (3.3V or 5V).
• Power Supply: When using the RAW pin, ensure the input voltage does not exceed 12V to avoid damaging the onboard voltage regulator.
• Serial Communication: Use the TX and RX pins carefully, as they are shared with the USB-to-Serial adapter during programming.
• Reset Button: Press the reset button before uploading code if the board does not automatically reset.

Below is an example code to blink an LED connected to pin D13:

// Blink an LED connected to pin D13
// This example demonstrates basic digital output functionality.

void setup() {
  pinMode(13, OUTPUT); // Set pin D13 as an output
}

void loop() {
  digitalWrite(13, HIGH); // Turn the LED on
  delay(1000);            // Wait for 1 second
  digitalWrite(13, LOW);  // Turn the LED off
  delay(1000);            // Wait for 1 second
}

1. The board is not detected by the computer:

   • Ensure the USB-to-Serial adapter is properly connected to the board.
   • Verify that the correct COM port is selected in the Arduino IDE.
   • Check that the adapter's voltage level matches the board variant (3.3V or 5V).

2. Code upload fails:

   • Press the reset button on the board just before uploading the code.
   • Ensure the correct board and processor are selected in the Arduino IDE (Tools > Board > Arduino Pro Mini and Tools > Processor).

3. The board overheats:

   • Check the input voltage on the RAW pin. It should not exceed 12V.
   • Ensure that the connected components do not draw more current than the board can supply.

4. Analog readings are inaccurate:

   • Verify that the input voltage to the board is stable and within the specified range.
   • Use proper grounding for all connected components.

Q: Can I power the Arduino Pro Mini with a battery?
A: Yes, you can power the board using a battery. Connect the battery's positive terminal to the RAW pin (for unregulated voltage) or the VCC pin (for regulated voltage), and the negative terminal to GND.

Q: How do I choose between the 3.3V and 5V variants?
A: Choose the 3.3V variant for low-power applications or when interfacing with 3.3V components. Use the 5V variant for higher performance and compatibility with 5V components.

Q: Can I use the Arduino Pro Mini for wireless communication?
A: Yes, you can connect wireless modules like Bluetooth (e.g., HC-05) or Wi-Fi (e.g., ESP8266) to the board via the UART or digital pins.

Q: Does the Arduino Pro Mini support I2C and SPI?
A: Yes, the board supports both I2C (pins A4 and A5) and SPI (pins D10, D11, D12, and D13) communication protocols.

By following this documentation, you can effectively use the Arduino Pro Mini for a wide range of projects and applications.