How to Use Arduino Micro (Rev3): Examples, Pinouts, and Specs

The Arduino Micro (Rev3) is a compact microcontroller board based on the ATmega32U4. It is a member of the Arduino family and is notable for its small size, making it ideal for embedding into projects where space is at a premium. The board comes with built-in USB communication, eliminating the need for a secondary processor. This feature allows the Arduino Micro to appear as a mouse or keyboard, in addition to a virtual (CDC) serial / COM port. It is commonly used in prototyping, DIY electronics, educational projects, and interactive artworks.

• Wearable electronics
• Prototyping IoT devices
• USB peripheral development
• Educational projects and learning platforms
• Small-scale robotics
• Interactive art installations

• Microcontroller: ATmega32U4
• Operating Voltage: 5V
• Input Voltage (recommended): 7-12V
• Input Voltage (limits): 6-20V
• Digital I/O Pins: 20
• PWM Channels: 7
• Analog Input Channels: 12
• DC Current per I/O Pin: 20 mA
• DC Current for 3.3V Pin: 50 mA
• Flash Memory: 32 KB (ATmega32U4) of which 4 KB used by bootloader
• SRAM: 2.5 KB (ATmega32U4)
• EEPROM: 1 KB (ATmega32U4)
• Clock Speed: 16 MHz
• LED_BUILTIN: Pin 13

1. Powering the Board:

   • Connect the board to a computer via a Micro USB cable to power it directly.
   • Alternatively, supply power through the Vin pin with an external power source between 7-12V.

2. Programming the Board:

   • Install the Arduino IDE from the official Arduino website.
   • Connect the Arduino Micro to your computer using a Micro USB cable.
   • Select 'Arduino Micro' from the Tools > Board menu in the Arduino IDE.
   • Write your sketch (program) and upload it to the board using the IDE.

3. Connecting I/O Devices:

   • Use the digital and analog pins to connect sensors, actuators, and other components.
   • Ensure that the components you connect are rated for the operating voltage and current of the pins.

• Always disconnect the board from power sources before making or altering connections.
• Do not exceed the recommended voltage and current ratings to avoid damaging the board.
• Use a current limiting resistor when connecting LEDs to the output pins.
• Utilize the onboard LED connected to pin 13 for testing and debugging purposes.
• When using PWM pins, ensure that the connected devices are compatible with PWM signals.

• Board not recognized by the computer:

  • Check the USB cable and port.
  • Ensure the correct drivers are installed.
  • Try resetting the board by briefly pressing the reset button.

• Sketch not uploading:

  • Verify that the correct board and port are selected in the Arduino IDE.
  • Check for errors in the code that may prevent compilation.
  • Ensure the bootloader is functioning correctly.

• Unexpected behavior in circuits:

  • Double-check wiring and connections.
  • Ensure power supply stability and adequacy.
  • Review the code for logical errors or incorrect pin assignments.

• Use the Arduino IDE's Serial Monitor to debug and print out messages from the board.
• Isolate the problem by reducing the circuit to its simplest form and gradually adding components.
• Consult the Arduino forums and community for support and advice.

Here's a simple example of blinking the onboard LED:

// Pin 13 has an LED connected on most Arduino boards.
int led = 13;

// The setup routine runs once when you press reset:
void setup() {                
  // Initialize the digital pin as an output.
  pinMode(led, OUTPUT);     
}

// The loop routine runs over and over again forever:
void loop() {
  digitalWrite(led, HIGH);   // Turn the LED on (HIGH is the voltage level)
  delay(1000);               // Wait for a second
  digitalWrite(led, LOW);    // Turn the LED off by making the voltage LOW
  delay(1000);               // Wait for a second
}

Remember to wrap code comments as needed to limit line length to 80 characters. This helps maintain readability in various editors and documentation formats.