Android and RS-485 how to make friends?

Question

Android

Hello, I have a tablet on Android 4.2.2, you need to use it to communicate with the controller via RS-485.
The connection is as follows:
1) Tablet with USB-HOST (OTG)
2) USB to RS-485 converter
Tried https://code.google.com/p/android-serialport-api/w... but not at all the right moment, everything flies.
Tell me what options are there quickly and without additional foreign fees to start all this and to work stably?
And also tell me if there is some kind of emulator to transfer data from the tablet to the PC (emulator) and vice versa.
Thanks in advance !

Answer 1

In QT5, it seems like qserialport is finished. There, the only problem is that qserialport has nowhere to write the lock file, and without it it does not want to work.
Try to work with the port from the NDK.
In general, using OTG and micro-usb in a basement-shop environment (and where else can you meet RS485?) is not good. The micro-usb connector is a frank crap in terms of reliability.
Want to use a tablet instead of an industrial PC? Use Bluetooth<-> serial or wifi<->serial.