When radio silence was required during WW2, the RAF used signal lights.
I made an Arduino morse message flasher. Holds about 100 messages of up to 140 characters each, and selects them at random.
https://www.youtube.com/shorts/vIycoHjHJU4.
I made an Arduino morse message flasher. Holds about 100 messages of up to 140 characters each, and selects them at random.
https://www.youtube.com/shorts/vIycoHjHJU4.