on app, I wrote with Serial.write("rrr".getBytes()), but arduino doesn't received.

[kotran88]

android code is as below I checked Serialport is opened, then I write string data to arduino

     ` serialPort = UsbSerialDevice.createUsbSerialDevice(UsbSerialDevice.CP210x, device, connection,0);
                if (serialPort != null) {
                    Toast.makeText(getApplicationContext(),"opened!!!",Toast.LENGTH_SHORT).show();
                    Log.e("dialog","serialport : "+serialPort.toString());

                    serialPort.setBaudRate(9600);
                    serialPort.setDataBits(UsbSerialInterface.DATA_BITS_8);
                    serialPort.setStopBits(UsbSerialInterface.STOP_BITS_1);
                    serialPort.setParity(UsbSerialInterface.PARITY_NONE);
                    serialPort.setFlowControl(UsbSerialInterface.FLOW_CONTROL_OFF);

                    serialPort.write("rrr".getBytes());

                    serialPort.read(mCallback); //

                } else {
                    Log.e("dialog", "PORT IS NULL");
                }`

on arduino, loop(){ }

I added blink to recognize arduino is received string data well. but not blinking at all... what did I do wrong.

[kotran88]

my git address to refer is...

https://github.com/kotran88/SerialPrinting

[feder240516]

could you solve this? having same problem here

[helaquiz]

You need to write in other function see the example https://github.com/felHR85/UsbSerial/tree/master/example

And in Arduino you need to begin the serial port