How to Use Arduino MKR Zero: Examples, Pinouts, and Specs

The Arduino MKR Zero is a compact microcontroller board powered by the SAMD21 Cortex-M0+ 32-bit ARM processor. Designed for Internet of Things (IoT) applications, it combines powerful processing capabilities with low power consumption. The board features a built-in SD card slot for data logging, USB connectivity for easy programming and communication, and a small form factor ideal for portable and embedded projects.

• Data logging and storage using the SD card slot
• IoT devices and smart sensors
• Audio processing and playback
• Portable and battery-powered projects
• Educational and prototyping purposes

1. Powering the Board:

   • Use the VIN pin (5V to 6V) or connect via the Micro USB port.
   • Ensure the power source provides sufficient current for your application.

2. Programming the Board:

   • Connect the board to your computer using a Micro USB cable.
   • Open the Arduino IDE, select "Arduino MKR Zero" from the board menu, and upload your code.

3. Using the SD Card Slot:

   • Insert a formatted microSD card into the slot.
   • Use the SD library in the Arduino IDE to read/write data to the card.

4. Connecting Sensors and Actuators:

   • Use the digital and analog pins for interfacing with sensors, actuators, and other peripherals.
   • For I2C or SPI devices, connect to the appropriate communication pins.

• Voltage Levels: The MKR Zero operates at 3.3V. Ensure all connected components are compatible with 3.3V logic levels to avoid damage.
• Power Consumption: For battery-powered projects, use the low-power features of the SAMD21 processor to extend battery life.
• SD Card Compatibility: Use microSD cards formatted with FAT16 or FAT32 for best results.
• Libraries: Install the required libraries (e.g., SD, SPI) in the Arduino IDE for specific functionalities.

#include <SPI.h>
#include <SD.h>

const int chipSelect = 4; // SD card chip select pin

void setup() {
  Serial.begin(9600); // Initialize serial communication
  while (!Serial) {
    ; // Wait for the serial port to connect
  }

  Serial.println("Initializing SD card...");
  
  if (!SD.begin(chipSelect)) {
    Serial.println("Card failed, or not present");
    // Stop the program if the SD card is not detected
    while (1);
  }
  Serial.println("Card initialized successfully.");
  
  // Open the file for reading
  File dataFile = SD.open("example.txt");
  if (dataFile) {
    Serial.println("Reading from example.txt:");
    while (dataFile.available()) {
      Serial.write(dataFile.read()); // Print file contents to Serial Monitor
    }
    dataFile.close(); // Close the file
  } else {
    Serial.println("Error opening example.txt");
  }
}

void loop() {
  // Nothing to do here
}

1. The board is not detected by the Arduino IDE:

   • Ensure the correct board ("Arduino MKR Zero") and port are selected in the IDE.
   • Check the USB cable and connection. Use a data-capable USB cable, not a charge-only cable.

2. SD card is not recognized:

   • Verify the SD card is properly inserted and formatted as FAT16 or FAT32.
   • Check the wiring to the SD card slot and ensure the chipSelect pin is correctly defined in your code.

3. Power issues:

   • Ensure the power supply provides sufficient voltage (5V to 6V) and current.
   • Avoid connecting components that exceed the 3.3V logic level.

4. Code upload fails:

   • Press the reset button on the board and try uploading the code again.
   • Ensure no other program is using the COM port.

Q: Can I power the MKR Zero with a battery?
A: Yes, you can power the board using a Li-Po battery (3.7V) connected to the battery connector or via the VIN pin (5V to 6V).

Q: What is the maximum size of the SD card supported?
A: The MKR Zero supports microSD cards up to 32GB formatted with FAT16 or FAT32.

Q: Can I use the MKR Zero with Arduino shields?
A: The MKR Zero is not directly compatible with standard Arduino shields due to its smaller form factor. However, you can use jumper wires or adapters to connect shields.

Q: Does the MKR Zero support Wi-Fi or Bluetooth?
A: No, the MKR Zero does not have built-in Wi-Fi or Bluetooth. For wireless connectivity, consider using external modules or other MKR boards like the MKR WiFi 1010.