I’m new to arduino and i have searched for an answer to this for a few hours now.
Basically my Uno board was working great and I have ben ploughing through the sparkfun examples, but yesterday things started to go funny. Long story but I but I stripped back the breadboard to the basic “Blink” configuration and now I see the issue. Basically when I digitalwrite HIGH to a pin with just an LED on it, it turns it OFF, and when I send LOW it turns it on, opposite effect to what you would expect. THE LED on the board behaves fine on PIN 13, but if I attach an LED to PIN 13 like in example 1, it behaves in the opposite. This is now true on on my output pins.
Any help would be greatfully received as its driven me crazy!