How to Use Adafruit Feather M0 Bluefruit LE: Examples, Pinouts, and Specs

The Adafruit Feather M0 Bluefruit LE is a compact, powerful microcontroller equipped with Bluetooth Low Energy (LE) for wireless communication. It is designed around the ATSAMD21G18 ARM Cortex M0+ processor, which operates at 48MHz. This board is ideal for a variety of projects, including IoT devices, wearable technology, and smart home applications. Its compatibility with the Arduino IDE allows for a familiar programming environment, making it accessible for both beginners and experienced developers.

• Microcontroller: ATSAMD21G18, 32-bit ARM Cortex M0+
• Clock Speed: 48 MHz
• Operating Voltage: 3.3V
• Input Voltage: 3.7-6V via battery and USB
• Digital I/O Pins: 20
• PWM Channels: 10
• Analog Input Channels: 6 (12-bit ADC)
• Analog Output Channels: 1 (10-bit DAC)
• Flash Memory: 256 KB
• SRAM: 32 KB
• EEPROM: None (can emulate up to 16 KB with the onboard flash)
• Bluetooth: Bluetooth Low Energy (LE) 4.0 module

1. Powering the Board: Connect a 3.7V LiPo battery to the JST connector for portable applications or power the board via the USB connection.
2. Programming: Use a micro USB cable to connect the board to your computer. Select "Adafruit Feather M0" from the Boards menu in the Arduino IDE.
3. Connecting Bluetooth: Pair the Feather M0 Bluefruit LE with other Bluetooth LE devices for wireless data transfer.
4. Digital & Analog I/O: Utilize the digital and analog pins for interfacing with sensors, actuators, and other components.

• Always disconnect the battery or USB power before making or altering connections.
• Use a current limiting resistor with LEDs and other sensitive components.
• Avoid exposing the board to static electricity or physical stress.
• Ensure the correct orientation and alignment of the board when connecting shields or components.

• Board not recognized by computer: Check the USB cable and port, try a different cable or port, or press the reset button twice quickly to enter bootloader mode.
• Bluetooth not connecting: Ensure the device is in range, the battery is charged, and the board is not paired with another device.
• Sketch not uploading: Verify the correct board and port are selected in the Arduino IDE, and the bootloader is not corrupted.

• If the board is not responding, perform a hard reset by briefly connecting the RST pin to GND.
• For Bluetooth issues, check the antenna area for obstructions and ensure the module's firmware is up to date.
• Use the serial monitor to debug and monitor data sent to and from the board.

Q: Can I use the Feather M0 Bluefruit LE with Arduino shields? A: Yes, it is compatible with FeatherWing shields designed for the Feather form factor.

Q: How do I update the Bluetooth module's firmware? A: Follow Adafruit's guide on updating the Bluefruit module using the Bluefruit LE Connect app.

Q: What is the maximum Bluetooth range? A: The typical range is up to 10 meters (33 feet), but it can vary based on environmental factors.

#include <Adafruit_BLE.h>
#include <Adafruit_BluefruitLE_SPI.h>

// Define the pins for the SPI connection
#define BLUEFRUIT_SPI_CS               8
#define BLUEFRUIT_SPI_IRQ              7
#define BLUEFRUIT_SPI_RST              4    // Optional but recommended, set to -1 if unused

// Create the bluefruit object
Adafruit_BluefruitLE_SPI ble(BLUEFRUIT_SPI_CS, BLUEFRUIT_SPI_IRQ, BLUEFRUIT_SPI_RST);

void setup() {
  Serial.begin(115200);
  Serial.println(F("Adafruit Bluefruit Feather M0 Example"));
  Serial.println(F("Initializing..."));

  // Initialise the module
  ble.begin();

  // Perform a factory reset to make sure everything is in a known state
  ble.factoryReset();

  // Set the device name
  ble.sendCommandCheckOK(F("AT+GAPDEVNAME=Feather M0"));
}

void loop() {
  // Placeholder for code to run repeatedly
}

Note: This example assumes you are using the Adafruit BluefruitLE SPI library. Ensure you have installed the necessary libraries through the Arduino Library Manager before compiling.