This one is not so much of a "challenge" as it is an engaging activity that excites the kids. I had more parents comment about their kids coming home talking about this challenge than many of the others. About mid year, my students start to work on different coding challenges. One of the first activities we do is a coding without computers challenge. We have a few weeks where Friday challenges are all about secret messages using encryption like PigPen Cipher and allowing kids to create their own.
One of the Friday Challenges is about the use of Morse and Binary Codes. The activity that follows the discussion is to create a necklace or bracelet using either Morse or Binary code (binary code max of 3 letters....usually initials). During our discussions we chat about the uses of each of these codes systems and the importance of each. At some point, every year, at least one student brings up how Morse Code isn't that important anymore. So I show them this video. THEN we talk about what we just saw. This video is of Admiral Jeremiah Denton. He was a POW during the Vietnam War. He is being interviewed and is asked how he is doing and explains the conditions he is living in. While his words say he is fine, getting medical treatment, getting regular meals, he is blinking in Morse Code the word TORTURE. Very powerful.