Can anyone guess why UsbSerialDevice is null?

[kotran88]

Hello :) I made custom pcb wired with cp2102, usb -c and esp8266 to send data to phone.

pcb is wired like cp2102's D+ and D- is connected to usb-c 's D+ and D- and cp2102 ' rx tx is connected to mcu's tx,rx

I tested code below to node mcu which has cp2102 and work quite well(UsbSerialDevice is not null and later, open well)

            connection = manager.openDevice(device);
            Log.e("dialog","device is : "+device.toString());
           Log.e("dialog","connection is : "+connection);
          UsbSerialDevice serialPort = UsbSerialDevice.createUsbSerialDevice(device, connection);

But when I tested with my custom pcb, UsbSerialDevice is always null... with custom pcb, Log above says below. device and connection is not null at all.

UsbDevice[mName=/dev/bus/usb/001/002,mVendorId=4554,mProductId=529,mClass=0,mSubclass=0,mProtocol=0,mManufacturerName=Silicon Labs,mProductName=Verifone USB to Modem,mVersion=1.00,mSerialNumber=0001,mConfigurations=[ UsbConfiguration[mId=1,mName=null,mAttributes=128,mMaxPower=50,mInterfaces=[ UsbInterface[mId=0,mAlternateSetting=0,mName=Verifone USB to Modem,mClass=255,mSubclass=0,mProtocol=0,mEndpoints=[ UsbEndpoint[mAddress=129,mAttributes=2,mMaxPacketSize=64,mInterval=0] UsbEndpoint[mAddress=1,mAttributes=2,mMaxPacketSize=64,mInterval=0]]]]

and

connection is : android.hardware.usb.UsbDeviceConnection@d695098

but

UsbSerialDevice serialPort = UsbSerialDevice.createUsbSerialDevice(device, connection);

here comes error which serialPort is null...so I can't open it. can anyone guess why UsbSerialDevice is null even though device and connection is not null

My guess is that...node mcu's getDeviceId is : 1002 getProductId is : 60000,

but my custom pcb's getDeviceId is : 1002 getProductId is : 529... getProductId is different...? so createUsbSerialDevice return null..?

[felHR85]

What are your VID/PID? That methods only return null when the device is not supported

[felHR85]

If the problem still persists though. You could use

UsbSerialDevice serial = UsbSerialDevice.createUsbSerialDevice(UsbSerialDevice.CP210x, device, connection,0);

[kotran88]

Hello :) I'm using cp2102 bought from digikey... as I said Device id is same as node mcu but product id is diffeerent...and name is different... node mcu's usbdevice name is cp2102 usb to uart but my custom pcb 's usbdevice name is Verifone USB to Modem...it may be the reason library think my pcb is not supported...?

[felHR85]

@kotran88 Probably, Try to open it as I told you before :)