Winsoft ComPort for Android USB Serial 2.5 Full Source
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