Voltage Spikes on Digital Pin

Wow. I’ve really stepped on a hornets nest here. I am so sorry you have had such bad experiences with people not following strict protocol. I don’t think I’ll now progress to stage 2 of my errant troubleshooting in view of the flare-up arising from stage 1. At least you inadvertently answered my stage 1 question which sought to establish if I had a problem or not, and for that I thank you.