I have one custom made device for measuring current. This device can be connected to PC and communication is done over USB. It is based on FTDI chip. I have application written in Java and that application is using rxtxSerial.dll library and gnu.io.rxtx_2.1.7.4.jar. Now I want to port this application on my android device and I'm litte bit confused what to do that? All I have is android tablet (os version 4.1.1), OTG cable and this measuring device.
Should my device be rooted? Is there any kind of library that I can simply add to my Java Android application and read data over USB? Where to start?
I have tried to port existing application for PC using same library, but rxtxSerial.dll is missing and I can't transfer it to my android device.
I can really recommend the USB-Serial-For-Android library, it supports multiple popular usb-to-serial chips (also FTDI) and there is no rooting required. Check out the GitHub project here.
There is a project dedicated to serial communication on Android. android-serialport-api. I think, it is a good resource to start with.
FTDI also provides Android related resources.
来源：https://stackoverflow.com/questions/21800932/communicating-with-serial-usb-device-over-android