OK - new and frustrating data point! I loaded Arduino IDE onto my laptop. Same problem. Then I disconnected my laptop from mains power - now it works perfectly!!! WTF?!?! What does this mean?
BTW - I'm in USA - 110V mains power.
OK - new and frustrating data point! I loaded Arduino IDE onto my laptop. Same problem. Then I disconnected my laptop from mains power - now it works perfectly!!! WTF?!?! What does this mean?
BTW - I'm in USA - 110V mains power.