How to Use A-Star 32U4 Mini: Examples, Pinouts, and Specs

The A-Star 32U4 Mini LV is a compact, Arduino-compatible microcontroller board powered by the ATmega32U4 AVR microcontroller. It is designed by Pololu and features integrated USB functionality, which eliminates the need for a separate USB-to-serial adapter. This board is particularly suitable for projects where space is at a premium and low power consumption is crucial. Common applications include wearable devices, small robots, and portable instrumentation.

• Microcontroller: ATmega32U4
• Operating Voltage: 2.7V to 5.5V
• Input Voltage (recommended): 2.7V to 11.8V
• Digital I/O Pins: 15 (of which 4 provide PWM output)
• Analog Input Pins: 4
• DC Current per I/O Pin: 40 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
• USB: Native USB (Micro-USB connector)

To use the A-Star 32U4 Mini LV in a circuit:

1. Connect the VCC pin to a power supply within the recommended voltage range.
2. Connect the GND pin to the common ground of your circuit.
3. Utilize the digital and analog pins as required for your application, ensuring you do not exceed the current ratings.
4. If USB connectivity is required, connect the board to a computer or USB host using a Micro-USB cable.

The A-Star 32U4 Mini LV can be programmed using the Arduino IDE:

1. Download and install the Arduino IDE from the official Arduino website.
2. Connect the A-Star 32U4 Mini LV to your computer using a Micro-USB cable.
3. Select "Arduino Leonardo" from the Tools > Board menu (the A-Star 32U4 Mini LV is compatible with the Leonardo bootloader).
4. Choose the correct serial port from Tools > Port.
5. Write your sketch and upload it to the board using the IDE.

• Always ensure that the power supply voltage does not exceed the maximum rating.
• When connecting peripherals that draw significant current, consider using an external power source to avoid overloading the board's voltage regulator.
• Use a current-limiting resistor when connecting LEDs to the digital I/O pins.

• Board not recognized by the computer: Ensure that the Micro-USB cable is properly connected and that the cable supports data transfer.
• Sketch not uploading: Check the selected board and port in the Arduino IDE. Ensure that the bootloader is functioning correctly.
• Unexpected behavior in circuits: Verify that all connections are secure and that power supply levels are within the specified range.

Q: Can I power the A-Star 32U4 Mini LV directly from a battery? A: Yes, you can power the board directly from a battery within the recommended voltage range.

Q: What is the difference between the A-Star 32U4 Mini LV and the Arduino Leonardo? A: The A-Star 32U4 Mini LV is similar to the Arduino Leonardo in terms of the microcontroller used but is much smaller in size and has a different pinout.

Q: How do I reset the board? A: You can reset the board by briefly connecting the RESET pin to GND.

For further assistance, consult the Pololu support forum or the extensive resources available on the Pololu website.

Below is a simple example of how to blink the onboard LED on the A-Star 32U4 Mini LV using the Arduino IDE:

// Pin 13 has an LED connected on most Arduino boards.
// give it a name:
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
}

This code will toggle the onboard LED on and off every second. Remember to select "Arduino Leonardo" as the board when uploading this sketch to the A-Star 32U4 Mini LV.