How to Use Adafruit Bluefruit LE Micro: Examples, Pinouts, and Specs

The Adafruit Bluefruit LE Micro is a versatile Bluetooth Low Energy (BLE) breakout board that combines a BLE module with an ATmega32u4 microcontroller. This compact component is designed to add wireless communication capabilities to a wide range of projects, allowing them to interact with smartphones, tablets, and other BLE-compatible devices. It is particularly useful for wearable electronics, wireless sensor networks, and IoT applications.

• Microcontroller: ATmega32u4
• Bluetooth Module: Nordic nRF51822 (ARM Cortex-M0)
• Operating Voltage: 3.3V
• Input Voltage (recommended): 4-12V DC
• Input Voltage (limits): 3.3-16V DC
• I/O Pins: 20 (including 7 PWM outputs and 12 analog inputs)
• 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
• Supported Bluetooth Profiles: GAP, GATT, HID, etc.
• Frequency: 2.4 GHz ISM band
• Antenna: PCB Antenna / u.FL connector for external antenna

To use the Adafruit Bluefruit LE Micro in a circuit:

1. Connect the VIN pin to a 4-12V DC power source.
2. Connect the GND pin to the ground of your power supply.
3. Utilize the digital and analog pins (D2-D13 and A0-A5) as needed for your project.
4. If necessary, connect the RST pin to a pushbutton for manual resetting.
5. For BLE communication, pair the device with a BLE-compatible smartphone, tablet, or computer.

• Ensure that the input voltage does not exceed the recommended limits to prevent damage.
• Use the onboard 3.3V regulator output (3V3 pin) to power external 3.3V components.
• When programming, select "Adafruit Bluefruit Micro" from the Arduino IDE's board menu.
• To reduce power consumption, utilize the BLE module's sleep modes when not actively communicating.

#include <SPI.h>
#include <Adafruit_BLE_UART.h>

// Create the bluefruit object, using SPI interface
Adafruit_BLE_UART ble(SPI_CS, SPI_IRQ, SPI_RST);

void setup(void) {
  Serial.begin(9600);
  ble.begin();
}

void loop() {
  // Tell the nRF8001 to do whatever it should be working on.
  ble.poll();

  // Check for incoming data from the BLE module
  if ( ble.available() ) {
    while (ble.available()) {
      char c = ble.read();
      Serial.print(c);
    }
    // Add your code here to handle the incoming data
  }
}

Note: The above code is a basic setup for initializing the BLE module and reading incoming data. You will need to install the Adafruit BLE library for Arduino to use this code.

• Device not powering on: Check the input voltage and connections to VIN and GND.
• No BLE communication: Ensure the device is correctly paired and within range.
• Sketch not uploading: Verify the correct board is selected in the Arduino IDE and the bootloader is functioning.

• If the device is not recognized by your computer, try pressing the RST button twice quickly to enter bootloader mode.
• For range issues, consider using an external antenna if the onboard antenna does not suffice.
• Always disconnect the board from power before making or altering connections to prevent damage.

Q: Can I use the Adafruit Bluefruit LE Micro with a 5V system? A: Yes, but ensure that the logic levels are compatible. The board operates at 3.3V.

Q: How do I update the firmware on the BLE module? A: Firmware updates can be done via the DFU protocol. Adafruit provides detailed guides on their website.

Q: What is the maximum range of the BLE communication? A: The range can vary depending on environmental factors but typically is around 10 meters (33 feet) with the onboard antenna.

For further assistance, consult the Adafruit forums or the extensive guides available on the Adafruit Learning System.