[mc32]

I think you'll be fine.

Friend of mine had a kind home-made led flashlight (small PCB and gangly wires). Friend was pulled aside for questioning and demonstrated its 'torch' capability and then let go thru. The delay was about 20 minutes though. It is silly, but if they've not studied any (even basic breadboarding) electronics, then anything out of the ordinary like that will look 'weird' and arouse caution.