private SpiDevice spiDevice;
private SpiDevice spiDevice2;

private static final String SPI_PORT = "SPI0.0";
private static final String SPI_PORT2 = "SPI0.1";

private Rc522 mRc522;

@Override
public void onCreate(Bundle savedInstanceState) {
  PeripheralManager pioService = PeripheralManager.getInstance();
  try {
      spiDevice = pioService.openSpiDevice(SPI_PORT);
      spiDevice2 = pioService.openSpiDevice(SPI_PORT2);

      mRc522 = new Rc522(spiDevice, spiDevice2, gpioReset);
 ...

private SpiDevice device;
private SpiDevice device2;

private Gpio resetPin;
private int busSpeed = 1000000;
private int busSpeed2 = 13650000;  //13.65khz

public Rc522(SpiDevice spiDevice, SpiDevice spiDevice2, Gpio resetPin) throws IOException {
    this.device = spiDevice;
    this.device2 = spiDevice2;

    initializePeripherals();
}

 /**
 *  Performs the initial configuration on hardware ports
 * @throws IOException if the hardware board had a problem with its hardware ports
 */
 private void initializePeripherals() throws IOException {
    device.setFrequency(busSpeed);
    device2.setFrequency(busSpeed2);
    resetPin.setDirection(Gpio.DIRECTION_OUT_INITIALLY_HIGH);
    initializeDevice();
}

/**
 * Performs the initial device setup and configure the pins used
 */
private void initializeDevice(){
    reset();
    writeRegister(REGISTER_TIMER_MODE, (byte) 0x8D);
    writeRegister(REGISTER_TIMER_PRESCALER_MODE, (byte) 0x3E);
    writeRegister(REGISTER_TIMER_RELOAD_LOW, (byte) 30);
    writeRegister(REGISTER_TIMER_RELOAD_HIGH, (byte) 0);
    writeRegister(REGISTER_TX_MODE, (byte) 0x40);
    writeRegister(REGISTER_MODE, (byte) 0x3D);
    setAntenna(true);
}

 /**
 * Writes to a RC522 register
 * @param address The address to write to
 * @param value The value that will be written
 */
private void writeRegister(byte address, byte value){
    //Log.d(TAG, "writeRegister -->" + address);
    //Log.d(TAG, "writeValue -->" + value);

    byte buffer[] = {(byte) (((address << 1) & 0x7E)), value};
    //Log.d(TAG, "writeBuffer -->" + buffer.toString());
    byte response[] = new byte[buffer.length];
    try {
        device.transfer(buffer, response, buffer.length);
        //device2.transfer(buffer, response, buffer.length);
    } catch (IOException e) {
        e.printStackTrace();
    }
}

/**
 * Reads the current value on the RC522's register
 * @param address The address to read from
 * @return the byte value currently stored in the register
 */
public byte readRegister(byte address){
    byte buffer[] = {(byte) (((address << 1) & 0x7E) | 0x80), 0};
    byte response[] = new byte[buffer.length];
    try {
        device.transfer(buffer, response, buffer.length);
        //device2.transfer(buffer, response, buffer.length);
        return response[1];
    } catch (IOException e) {
        e.printStackTrace();
        return 0;
    }
}