On Windows, you can read a serial port as if it was a file name:
Very simple really. Can the same be done on Android? If not, how does one read from a serial port connected to a USB drive via an RS232 to USB adapter? I googled till I was blue in the face, maybe I am googling for the wrong thing.
You can probably access the underlying Linux device, which is typically something like "/dev/ttyS0", although USB serial devices sometimes have their own naming conventions. I'm having another moment of senility, but I think it's "/dev/ttyUSB0", for example.
An IDE is no substitute for an Intelligent Developer.