Can't find the inner printer

[lightning331]

I am using the Sunmi V2.
(https://www.amazon.com/Thermal-Bluethooth-Compatible-Loyverse-CashStock/dp/B07XKQQKTG/ref=sr_1_3?dchild=1&gclid=Cj0KCQiAqdP9BRDVARIsAGSZ8AkhVNPT1GdhicFNdsuOZAS6yGZOGQCNgTipf0qBaz2_t6GsL6MdYYAaAv_WEALw_wcB&hvadid=386279051701&hvdev=c&hvlocphy=9007754&hvnetw=g&hvqmt=b&hvrand=4302453039542365253&hvtargid=kwd-425465870078&hydadcr=22333_9728250&keywords=sunmi+pos&qid=1605709884&sr=8-3&tag=googhydr-20)

When I install the project and click the button - "PRINT BY BLUETOOTH!" on the device, the app doesn't recognize the inner printer.
It says "No printer".

If I test the printer with the default app installed on the device, it works well.

Any resolution?

[DantSu]

May be it's not bluetooth connection.

[lightning331]

But I see it in the connected Bluetooth list exactly.

[lightning331]

If I test this library - https://github.com/shangmisunmi/SunmiPrinterDemo, it works fine.
I am not sure what's wrong with me.

[DantSu]

use BluetoothConnections : https://github.com/DantSu/ESCPOS-ThermalPrinter-Android/blob/master/escposprinter/src/main/java/com/dantsu/escposprinter/connection/bluetooth/BluetoothConnections.java

        BluetoothConnection[] bluetoothDevicesList = (new BluetoothConnections()).getList();

        if (bluetoothDevicesList == null) {
            return null;
        }

        int i = 0;
        BluetoothConnection[] printersTmp = new BluetoothConnection[bluetoothDevicesList.length];
        for (BluetoothConnection bluetoothConnection : bluetoothDevicesList) {
            BluetoothDevice device = bluetoothConnection.getDevice();

            int majDeviceCl = device.getBluetoothClass().getMajorDeviceClass(),
                    deviceCl = device.getBluetoothClass().getDeviceClass();

            // Find the correct one HERE
        }

[DantSu]

It seems that this printer haven't a classic DeviceClass or MajorDeviceClass.

[DantSu]

One more thing, Are you sure that this printer is compatible with ESC/POS commands (EPSON Standard Commands) ?

[lightning331]

When I debug the app, I get 0 value with both majDeviceCl and deviceCl.
How can I check this supports EPSON Standard Commands?

[DantSu]

Try this :

        BluetoothConnection[] bluetoothDevicesList = (new BluetoothConnections()).getList();

        if (bluetoothDevicesList == null) {
            return null;
        }

        int i = 0;
        BluetoothConnection[] printersTmp = new BluetoothConnection[bluetoothDevicesList.length];
        for (BluetoothConnection bluetoothConnection : bluetoothDevicesList) {
            BluetoothDevice device = bluetoothConnection.getDevice();
            Log.i("BLUETOOTH DEVICE", device.getName());
        }

Do you find your printer ?

[lightning331]

It shows as "InnnerPrinter".

[DantSu]

    /**
     * Get a list of bluetooth printers.
     *
     * @return an array of EscPosPrinterCommands
     */
    @SuppressLint("MissingPermission")
    public BluetoothConnection[] getList() {
        BluetoothConnection[] bluetoothDevicesList = super.getList();

        if (bluetoothDevicesList == null) {
            return null;
        }

        int i = 0;
        BluetoothConnection[] printersTmp = new BluetoothConnection[bluetoothDevicesList.length];
        for (BluetoothConnection bluetoothConnection : bluetoothDevicesList) {
            BluetoothDevice device = bluetoothConnection.getDevice();
            if (device.getName().equals("InnerPrinter")) {
                printersTmp[i++] = new BluetoothConnection(device);
            }
        }
        BluetoothConnection[] bluetoothPrinters = new BluetoothConnection[i];
        System.arraycopy(printersTmp, 0, bluetoothPrinters, 0, i);
        return bluetoothPrinters;
    }

[lightning331]

Ha, if I remove the condition for majDeviceCl and deviceCl, the print works well. :)

[DantSu]

keep this condition :

           if (device.getName().equals("InnerPrinter")) {
                printersTmp[i++] = new BluetoothConnection(device);
            }

[lightning331]

OK, so I will change the condition as follows.

from if (majDeviceCl == BluetoothClass.Device.Major.IMAGING && (deviceCl == 1664 || deviceCl == BluetoothClass.Device.Major.IMAGING))
=>
to if ((majDeviceCl == BluetoothClass.Device.Major.IMAGING && (deviceCl == 1664 || deviceCl == BluetoothClass.Device.Major.IMAGING)) || (device.getName().equals("InnerPrinter")))

Is it correct?

[DantSu]

public class MyBluetoothPrintersConnections extends BluetoothConnections {

    /**
     * Easy way to get the first bluetooth printer paired / connected.
     *
     * @return a EscPosPrinterCommands instance
     */
    public static BluetoothConnection selectFirstPaired() {
        BluetoothPrintersConnections printers = new MyBluetoothPrintersConnections();
        BluetoothConnection[] bluetoothPrinters = printers.getList();

        if (bluetoothPrinters != null && bluetoothPrinters.length > 0) {
            for (BluetoothConnection printer : bluetoothPrinters) {
                try {
                    return printer.connect();
                } catch (EscPosConnectionException e) {
                    e.printStackTrace();
                }
            }
        }
        return null;
    }


    /**
     * Get a list of bluetooth printers.
     *
     * @return an array of EscPosPrinterCommands
     */
    @SuppressLint("MissingPermission")
    public BluetoothConnection[] getList() {
        BluetoothConnection[] bluetoothDevicesList = super.getList();

        if (bluetoothDevicesList == null) {
            return null;
        }

        int i = 0;
        BluetoothConnection[] printersTmp = new BluetoothConnection[bluetoothDevicesList.length];
        for (BluetoothConnection bluetoothConnection : bluetoothDevicesList) {
            BluetoothDevice device = bluetoothConnection.getDevice();

            int majDeviceCl = device.getBluetoothClass().getMajorDeviceClass(),
                    deviceCl = device.getBluetoothClass().getDeviceClass();

            if (device.getName().equals("InnerPrinter")) {
                printersTmp[i++] = new BluetoothConnection(device);
            }
        }
        BluetoothConnection[] bluetoothPrinters = new BluetoothConnection[i];
        System.arraycopy(printersTmp, 0, bluetoothPrinters, 0, i);
        return bluetoothPrinters;
    }

}

[lightning331]

ok, but when there exists multiple printers, I think it is not a good way.
I have to select one of the connected printers in my app before starting the printing.