How to Use SparkFun SAMD21 Dev Breakout: Examples, Pinouts, and Specs

The SparkFun SAMD21 Dev Breakout is a versatile development board that harnesses the power of the Microchip ATSAMD21G18, an ARM Cortex-M0+ microcontroller. This board is an excellent choice for makers and hobbyists looking to step up from platforms like the Arduino Uno, as it provides a significant boost in performance and memory while maintaining a familiar programming environment through the Arduino IDE. Common applications include IoT devices, wearables, and complex control systems.

• Microcontroller: ATSAMD21G18, 32-bit ARM Cortex-M0+
• Operating Voltage: 3.3V
• Input Voltage: 5V (via USB) or 7-15V (via VIN)
• Digital I/O Pins: 20
• Analog Input Pins: 6
• PWM Output: 10
• UARTs: 1
• SPI Interfaces: 1
• I2C Interfaces: 1
• Flash Memory: 256KB
• SRAM: 32KB
• Clock Speed: 48MHz

1. Install the Arduino IDE from the official Arduino website.
2. Open the Arduino IDE, go to File > Preferences, and add the following URL to the "Additional Boards Manager URLs" field:

   https://adafruit.github.io/arduino-board-index/package_adafruit_index.json
   

3. Go to Tools > Board > Boards Manager, search for "SAMD", and install the "Arduino SAMD Boards" package.
4. Select the SparkFun SAMD21 Dev Breakout from Tools > Board.

• Ensure that the board is powered correctly through the USB or VIN pin.
• Connect digital and analog pins as required for your application, respecting the voltage and current limitations.
• Use the RESET pin to reset the microcontroller if necessary.

• Connect the board to your computer using a micro USB cable.
• Select the correct port from Tools > Port.
• Write your sketch and upload it to the board using the Upload button.

• Always disconnect the board from power sources before making or altering connections.
• Use a current limiting resistor with LEDs and other sensitive components.
• Avoid exposing the board to static discharge, moisture, or extreme temperatures.

• Board not recognized: Ensure that the correct drivers are installed and the USB cable is functioning.
• Sketch not uploading: Check the selected board and port in the Arduino IDE. Press the reset button twice quickly to enter bootloader mode if necessary.
• Unexpected behavior: Verify that the power supply is adequate and the pins are configured correctly in the sketch.

• Can I power the board with a battery? Yes, you can power the board with a battery connected to the VIN pin, within the 7-15V range.

• What is the maximum current per I/O pin? The maximum DC current per I/O pin is 7 mA.

• How do I use the onboard LED? The onboard LED is connected to pin 13. You can control it using digital write functions in your sketch.

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 adjust the pin number and settings according to the SparkFun SAMD21 Dev Breakout specifications when adapting code for this board.