Jesse Lee’s open-source Linux program called Open and Shut, which is available on GitHuballows you to enter messages in Morse code by opening and closing the laptop lid. It was demonstrated on a Lenovo Thinkpad laptop. Of course, not every laptop can withstand prolonged input in this way.
It’s hard to imagine practical cases where such an input might be needed, although further development could make the program more versatile. This method probably can’t be called covert input either, except in some cases — the movements of the laptop lid are very noticeable, and it’s not a small thing. Also, it’s unlikely that many people would want to face the risk of breaking off a laptop screen.
Previously, a modification was reported for transmissionand receiving Morse code messages on the Raspberry Pi and the Pi Zero W mod, which transforms Telegram messages in Morse code and flashing lights. Nowadays, Morse code is still quite valuable for applications where other electronic methods are unavailable or may fail, including communication on an airplane/boat and in rescue cases.
However, the open source program can be used for keyboard input or other methods. It is currently an experiment with no practical purpose.
Source: Tom`s Hardware