Arduino Compatible Pro Mini ATMEGA328P Board – Support Documentation
The Arduino Pro Mini is a compact, low-power microcontroller board based on the ATmega328P. Designed for embedded applications where space and power efficiency are paramount, it offers the full functionality of larger Arduino boards in a smaller footprint.
Key Features
- Microcontroller: ATmega328P
- Operating Voltage: 3.3V or 5V
- Clock Speed: 8 MHz (3.3V) or 16 MHz (5V)
- Digital I/O Pins: 14 (6 PWM outputs)
- Analog Input Pins: 6
- Flash Memory: 32 KB (of which 2 KB used by bootloader)
- SRAM: 2 KB
- EEPROM: 1 KB
- Dimensions: 33.3mm x 18.0mm
Pin Descriptions
| Pin | Function | Description |
|---|---|---|
| D0 (RX) | Digital I/O | Serial Receive (UART) |
| D1 (TX) | Digital I/O | Serial Transmit (UART) |
| D2 – D13 | Digital I/O | General Purpose Digital I/O Pins |
| D3, D5, D6, D9, D10, D11 | PWM | PWM Output (AnalogWrite) |
| A0 – A5 | Analog Input | Analog Inputs (10-bit ADC) |
| RAW | Power Input | Unregulated Voltage Input (3.35V to 12V) |
| VCC | Power Output | Regulated 3.3V or 5V Output |
| GND | Power | Ground |
| RST | Reset | Reset Pin (Active Low) |
Powering the Board
- RAW Pin: Connect an unregulated power source (3.35V to 12V). The onboard voltage regulator will convert it to the operating voltage.
- VCC Pin: Connect a regulated 3.3V or 5V power source directly, depending on the board version.
Programming the Board
The Arduino Pro Mini does not have an onboard USB-to-Serial converter. To program it, you’ll need an external USB-to-Serial adapter (e.g., FTDI Basic Breakout).
- Connect the FTDI adapter to the Pro Mini:
- FTDI TXO → Pro Mini RXI
- FTDI RXI → Pro Mini TXO
- FTDI VCC → Pro Mini VCC
- FTDI GND → Pro Mini GND
- FTDI DTR → Pro Mini DTR
- Open the Arduino IDE.
- Select the correct board:
- Board: “Arduino Pro or Pro Mini”
- Processor: “ATmega328P (3.3V, 8 MHz)” or “ATmega328P (5V, 16 MHz)” depending on your board version.
- Select the correct COM port.
- Upload your sketch.
Troubleshooting
- Problem: Sketch won’t upload.
- Solution: Ensure the FTDI adapter is correctly connected. Verify that the DTR pin is connected for automatic reset during upload.
- Problem: Board not powering on.
- Solution: Check power connections. If using the RAW pin, ensure the voltage is within the acceptable range (3.35V to 12V).
- Problem: Unstable behavior or resets.
- Solution: Verify that the power supply can provide sufficient current. Check for loose connections or shorts.
Frequently Asked Questions
- Can I use the Arduino Pro Mini for battery-powered projects?
- Yes, its low power consumption makes it ideal for battery-powered applications. Consider using the 3.3V version for lower power usage.
- Is the Arduino Pro Mini compatible with Arduino Uno sketches?
- Yes, as both use the ATmega328P microcontroller, most sketches are compatible. Ensure the correct board and processor are selected in the Arduino IDE.
- How do I reset the board manually?
- Press the onboard reset button or momentarily connect the RST pin to GND.
Additional Notes
- The Arduino Pro Mini is ideal for projects where space is limited.
- It does not include USB connectivity; an external adapter is required for programming.
- Ensure correct voltage levels when interfacing with other devices to prevent damage.