Thanks a7, appreciate your continued interest and encouragement.
After the help here I'm pleased to say that I got the 'LED emulation' version working yesterday. I then made the changes described in para 3 of my post #11, and was delighted to get that version working on the bench last night. I ran it successfully overnight, although the only videos recorded in some 14 hours were of me. No fox, the project's target!
Here's an image of my Polaroid CUBE (old, original version) :
I'll post my code later today, as I'd like to get suggestions on improvements, format, etc.
As you'll see, I changed from using if() for my main 'trigger determining' logic when the penny dropped that I should be detecting an edge. The motion sensor input goes low for about 18s (it's user settable and that's the minimum) and I want to start recording my video of whatever activated it asap after that. Once the CUBE is doing that for about 30s (together with displaying the red LED as an indicator during testing), I don't care what happens to the KA section. So I'm currently still using delay()s for the video part without unwanted practical consequences. My tests (with much shorter duration) confirmed that the KA photos did not interfere with the videos.
I'm new to 'FSM' but it seems that my latest version actually uses it!
