How to open multiple RC522 reader device on android things?

Question

I use Raspberry pi 3 model B on Android Things.

for RC522 communication, I use https://github.com/Galarzaa90/android-things-rc522

this source success work, only 1 RC522 reader device

but I want 2 RC522 devices.

if RC522 reader device only 1 connect.

GPIO set

SDA - GPIO 8 (SPI0 CS0) SCK - GPIO 11 (SPI0 SCLK) MOSI - GPIO 10 (SPI0 MOSI) MISO - GPIO 9 (SPI0 MISO) GND - GND RST - GPIO25 3.3V - 3.3V PWR

is work RC522 device.

and I would like to use 2 RC522 reader devices like the pictures.

this pictures set

SDA (blue) - SPI0 CS1(GPIO 7) , SPO0 CS0 (GPIO 8) 'SCK (green) - SPI0 SCLK MOSI (yellow) - SPI0 MOSI MISO (orange) - SPI0 MISO GND (red) - GND RST (Brown) - GPIO 25 3.3V (black) - 3.3V PWR

but Only the RC522 device to the left of the picture works.

first when I build with https://github.com/Galarzaa90/android-things-rc522 this source.

all RC522 devices not work.

with a little modification, I was able to operate only one RC522 device on the left.

MainActivity.class

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);
 ...

Rc522.class

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;
    }
}

I feel like I might be able to modify writeRegister() and readRegister() just a little bit.

perhaps,you have opened multiple devices in android things, if you have ever used an RC522 reader device.

please advice for me

thanks..

Answer 1

The functions should be something like this.

private void writeRegister(byte address, byte value,byte sensor_Number){
    //Log.d(TAG, "writeRegister -->" + address);
    //Log.d(TAG, "writeValue -->" + value);

    //Logic to pull the line high for the sensor other than the sensor_Number
    //Logic to pull the line low for the sensor_Number.

    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();
    }
}

public byte readRegister(byte address,byte sensor_Number){
    //Logic to pull the line high for the sensor other than the sensor_Number
    //Logic to pull the line low for the sensor_Number.

    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;
    }
}

Do write those commented logic yourself because I am useless when it comes to cpp.

edit : I don't know what the intialize device does but if it is configuring the RC522 Module, you need to do that for both the modules.