Try turning on debugging mode and use adb to connect to the device. You can manually redirect files to your phone (for example, to an SD card), which you can take turns to periodically check in your application. You can also write files in reverse order (from your application), and your PC application checks this file again over ADB. This way you can set up simple protocols for communication.
I also need this right now, but a little more complicated as I try to access the phone from a programmable integrated device with a USB host USB inside. Which probably means reverse engineering ADB ...
In any case, this is a rather hacky solution, but it should work on all phones while debugging is on, which makes it possible.
source share