Choosing the right Arduino board is key to the success of any project. Two popular choices, especially for compact designs, are the Arduino Pro Micro and the Arduino Nano. Both boards are small, powerful, and versatile, but they have distinct features that make them suitable for different types of projects. In this guide, we’ll compare the Arduino Pro Micro vs Arduino Nano to help you decide which is better for your next project.
What is Arduino Pro Micro?
The Arduino Pro Micro is a compact microcontroller board based on the ATmega32U4. What sets it apart is its built-in USB functionality, meaning it can act as a USB device like a mouse or keyboard without additional components. This feature makes it perfect for projects that require direct interaction with a computer or other USB-enabled devices.
Key Features of Arduino Pro Micro:
- Microcontroller: ATmega32U4
- Operating Voltage: 5V (or 3.3V version available)
- Digital I/O Pins: 12 (5 of which are PWM-enabled)
- Analog Input Pins: 9
- Flash Memory: 32 KB (4 KB used by the bootloader)
- SRAM: 2.5 KB
- EEPROM: 1 KB
- Clock Speed: 16 MHz (5V version) or 8 MHz (3.3V version)
Common Use Cases:
- Projects requiring USB functionality (e.g., DIY keyboards, game controllers)
- Compact designs where space is limited
- HID (Human Interface Device) projects like custom mice or keyboards
What is Arduino Nano?
The Arduino Nano is a miniature version of the Arduino Uno, based on the ATmega328P microcontroller. It’s highly popular for projects that need a compact, breadboard-friendly board with all the features of the Arduino Uno. The Nano is ideal for beginners and prototypers who need a small yet powerful board.
Key Features of Arduino Nano:
- Microcontroller: ATmega328P
- Operating Voltage: 5V
- Digital I/O Pins: 14 (6 of which are PWM-enabled)
- Analog Input Pins: 8
- Flash Memory: 32 KB
- SRAM: 2 KB
- EEPROM: 1 KB
- Clock Speed: 16 MHz
Common Use Cases:
- Breadboard prototyping
- Projects with basic sensor inputs and outputs
- Robotics, home automation, and simple electronic projects
Pinout Comparison: Arduino Pro Micro vs Arduino Nano
1. Digital I/O Pins
- Arduino Pro Micro: Offers 12 digital I/O pins, with 5 PWM pins. While this is slightly fewer than the Nano, it’s still versatile enough for most compact projects.
- Arduino Nano: Comes with 14 digital I/O pins, 6 of which are PWM-enabled, making it a bit more flexible for projects that involve multiple components like LEDs or motors.
2. Analog Input Pins
- Arduino Pro Micro: Has 9 analog input pins, providing a bit more flexibility for projects that require multiple sensors.
- Arduino Nano: Offers 8 analog input pins, which is typically sufficient for most beginner or intermediate projects.
Memory and Performance
Both the Arduino Pro Micro and the Arduino Nano have similar memory capacities, but they differ slightly in how they handle USB communication and HID projects.
- Arduino Pro Micro Memory:
- Flash Memory: 32 KB
- SRAM: 2.5 KB
- EEPROM: 1 KB
- The Pro Micro uses part of its flash memory for USB functions, which might slightly reduce the available space for your code.
- Arduino Nano Memory:
- Flash Memory: 32 KB
- SRAM: 2 KB
- EEPROM: 1 KB
Size and Form Factor
- Arduino Pro Micro:
- The Pro Micro is slightly smaller than the Nano, making it perfect for extremely compact designs or wearable technology. Its size is around 33 mm x 18 mm, making it ultra-portable.
- Arduino Nano:
- The Nano is 18 mm x 45 mm, which is still compact enough for most breadboard setups. It offers a small form factor without sacrificing functionality.
USB Functionality: Pro Micro’s Key Advantage
One of the main features that sets the Arduino Pro Micro apart from the Nano is its built-in USB functionality. Thanks to the ATmega32U4 microcontroller, the Pro Micro can act as a USB device, allowing you to create projects like custom keyboards, game controllers, and other HID projects. The Arduino Nano, based on the ATmega328P, doesn’t have this built-in USB functionality, so it’s less suited for projects that require direct interaction with a computer via USB.
Power Supply
Both the Pro Micro and Nano can be powered through a USB cable or an external power supply.
- Arduino Pro Micro: Available in both 5V and 3.3V versions, giving you more flexibility depending on your project’s power requirements.
- Arduino Nano: Typically operates at 5V, but also provides a 3.3V output for external components.
Which Board is Right for You?
- Choose the Arduino Pro Micro if:
- You need USB functionality (for HID devices like keyboards, game controllers).
- You’re working on a compact or wearable project.
- Your project requires slightly more analog input pins.
- You need a 3.3V version for low-power devices.
- Choose the Arduino Nano if:
- You need a breadboard-friendly board that’s easy to prototype with.
- You’re building projects that don’t require USB communication (e.g., robotics, basic electronics).
- You need a slightly larger number of digital I/O pins.
- You want a 5V board for simple sensor projects, LED control, or motors.
Conclusion: Arduino Pro Micro vs Arduino Nano
Both the Arduino Pro Micro and the Arduino Nano are excellent choices, but they serve different purposes. If you’re building a project that requires USB communication, such as a custom keyboard or a mouse, the Arduino Pro Micro is your best bet. On the other hand, if you’re looking for a board that’s easy to prototype with and has a slightly larger number of digital I/O pins, the Arduino Nano is ideal. Ultimately, the best choice depends on the specific needs of your project.
FAQ
- Can I use the same code on both the Arduino Pro Micro and Nano?
Yes, since both boards use the Arduino IDE, most code will work on both boards. However, the Pro Micro has built-in USB functionality, so if your code relies on HID features, it will only work on the Pro Micro. - Which board is better for compact projects?
The Arduino Pro Micro is slightly smaller and often a better choice for compact or wearable projects. - Do both boards support serial communication?
Yes, both the Arduino Pro Micro and Nano support serial communication. However, the Pro Micro also supports USB communication due to its built-in USB capabilities. - Is the Arduino Pro Micro more expensive than the Nano?
Typically, the Pro Micro is slightly more expensive due to its USB functionality and versatility. However, the price difference is usually small. - Can I use the Arduino Nano for USB HID projects?
No, the Arduino Nano does not have built-in USB capabilities like the Pro Micro. If you need to create a USB HID project (such as a custom keyboard or mouse), you’ll need to use the Pro Micro.