public void inputKeyevent(int value) {
    executeCommandQuietly(adbCommand("shell", "input", "keyevent", "" + value));
    // need to wait a beat for the UI to respond
    sleep(500);
  }
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