Arduino Pro Mini Atmega328P 3.3v/8MHz Blue (Compatible)

Features

• Microcontroller: ATmega328
• Operating Voltage: 3.3V
• Clock Speed: 8 MHz
• Flash Memory: 32 KB (0.5 KB used by bootloader)
• SRAM: 2 KB
• EEPROM: 1 KB
• Digital I/O Pins: 14 (of which 6 provide PWM output)
• Analog Input Pins: 8
• No USB interface – requires external FTDI/USB-to-Serial adapter for programming
• Low power consumption – great for battery-operated projects
• Compact size: 18mm x 33mm

Applications

• Wearable electronics
• IoT devices
• Battery-powered projects
• Sensor monitoring systems
• Embedded systems and compact robotics

Pin Description

• Digital I/O: D0 to D13 (PWM on D3, D5, D6, D9, D10, D11)
• Analog Inputs: A0 to A7
• Power Pins: VCC (3.3V), GND
• Reset: Active-low reset pin
• TX/RX: Serial communication pins (D0 for RX, D1 for TX)

Wiring and Programming

To program the Arduino Pro Mini, you need an FTDI USB-to-Serial adapter. Connect the following pins:

• FTDI VCC (3.3V) → VCC
• FTDI GND → GND
• FTDI TX → RXI (D0)
• FTDI RX → TXO (D1)
• FTDI DTR → GRN (auto-reset)

In the Arduino IDE:

• Select Board: “Arduino Pro or Pro Mini”
• Select Processor: “ATmega328P (3.3V, 8 MHz)”
• Select the correct COM port and upload code as usual.

Supported Protocols

• UART (Serial)
• I2C (Wire library, SDA on A4, SCL on A5)
• SPI (Pins 10-13)

Example Code

This basic sketch blinks the onboard LED (usually on pin 13):

void setup() {
  pinMode(13, OUTPUT);
}

void loop() {
  digitalWrite(13, HIGH);   // LED ON
  delay(1000);              // Wait 1 second
  digitalWrite(13, LOW);    // LED OFF
  delay(1000);              // Wait 1 second
}

Important Notes

• This board does not include a built-in USB interface. You need a 3.3V FTDI or USB-to-Serial adapter.
• Ensure the FTDI adapter matches the board's voltage (3.3V only).
• Use a regulated power supply if powering through VCC.