public String getExternalStoragePath() {
    return runAdbCommand("shell echo $EXTERNAL_STORAGE");
  }
Use adb to send a keyevent to the device.

Full list of keys available here:
http://developer.android.com/reference/android/view/KeyEvent.html

@param value - Key to be sent to 'adb shell input keyevent'
selendroid-standalone/src/main/java/io/selendroid/standalone/android/impl/AbstractDevice.java