XDA senior member Kemonine96 is showcasing what he calls the Universal Arduino Serial Adapter. Essentially, the device is an Arduino board designed to connect to a serial interface on a target device.
As the folks at XDA Devs note, the project is still very much a work in progress. Nevertheless, the image below shows an LCD screen, joystick and two buttons comprising the physical interface.
As expected, there are at least several ways for Android devices to link up with the serial adapter. Indeed, Kemonine included a micro USB connector so users can easily monitor the serial terminal on an Android device.
In addition, there is also an RJ-45 connector (Ethernet jack) to patch in expansion boards and connect a regular serial cable. Once connected and properly configured, the rig acts as a virtual bridge between the PC terminal and target Android device. Meaning, it displays incoming data, while relaying typed commands to the device.
Fortunately, the Universal Arduino Serial Adapter is 5V, 3.3V and 1.8V tolerant and is therefore compatible with a wide range of devices.
Interested? You can visit the official project thread here for additional details.