Delphi and C++ Builder serial communication library for USB connected devices for Android.

uses UsbSerial library
supports CP210x, CP2130, CDC, FTDI, PL2303 and CH34x devices
no special root access privileges needed
available for Delphi/C++ Builder XE6 - 10.3
source code included in registered version
royalty free distribution in applications

API
type
  TDataBits = (db5, db6, db7, db8);
  TStopBits = (sb1, sb15, sb2);
  TParity = (paNone, paOdd, paEven, paMark, paSpace);
  TFlowControl = (fcOff, fcRtsCts, fcDsrDtr, fcXonXoff);

  TOnBreakInterrupt = procedure of object;
  TOnCtsChanged = procedure(State: Boolean) of object;
  TOnDeviceAttached = procedure(Device: JUsbDevice) of object;
  TOnDeviceDetached = procedure(Device: JUsbDevice) of object;
  TOnDsrChanged = procedure(State: Boolean) of object;
  TOnFramingError = procedure of object;
  TOnOverrunError = procedure of object;
  TOnParityError = procedure of object;
  TOnReceivedData = procedure(Data: TJavaArray<Byte>) of object;

  EUsbSerialError = class(Exception);

  TUsbSerial = class
    constructor Create;

    function IsSupported(UsbDevice: JUsbDevice): Boolean;
    function HasPermission(UsbDevice: JUsbDevice): Boolean;
    procedure RequestPermission(UsbDevice: JUsbDevice);

    procedure Connect(UsbDevice: JUsbDevice);
    procedure Disconnect;

    procedure Open(Synchronous: Boolean = False);
    procedure Close;

    function Read(Buffer: TJavaArray<Byte>; Timeout: Integer = 0): Integer;
    function Read(Buffer: TArray<Byte>; Timeout: Integer = 0): Integer;
    function Read(var Data: Byte; Timeout: Integer = 0): Integer;

    function Write(Buffer: TJavaArray<Byte>; Timeout: Integer = 0): Integer;
    function Write(Buffer: TArray<Byte>; Timeout: Integer = 0): Integer;
    function Write(Data: Byte; Timeout: Integer = 0): Integer;

    procedure ClearDtr;
    procedure SetDtr;

    procedure ClearRts;
    procedure SetRts;

    property BaudRate: Integer read write;
    property Connected: Boolean read;
    property DataBits: TDataBits read write;
    property FlowControl: TFlowControl read write;
    property Opened: Boolean read;
    property Parity: TParity read write;
    property StopBits: TStopBits read write;
    property Synchronous: Boolean read;
    property UsbDevice: JUsbDevice read;
    property UsbDeviceConnection: JUsbDeviceConnection read;
    property UsbDevices: TArray<JUsbDevice> read;
    property UsbManager: JUsbManager read;
    property UsbSerialInterface: JUsbSerialInterface read;

    property OnBreakInterrupt: TOnBreakInterrupt read write;
    property OnCtsChanged: TOnCtsChanged read write;
    property OnDeviceAttached: TOnDeviceAttached read write;
    property OnDeviceDetached: TOnDeviceDetached read write;
    property OnDsrChanged: TOnDsrChanged read write;
    property OnFramingError: TOnFramingError read write;
    property OnOverrunError: TOnOverrunError read write;
    property OnParityError: TOnParityError read write;
    property OnReceivedData: TOnReceivedData read write;
  end;

function ToByteArray(JavaArray: TJavaArray<Byte>): TArray<Byte>;

Only for V.I.P