Most Recent Code Replace?

HI, I just did the first lesson and was able to get the LED blinking, thanks to dmjlambert. I then just practiced uploading the code for my next project. However, the LED will not blink now unless I upload it again. Does this mean that only the most recently uploaded code will work? Can you do something to the board to make it go to a previously uploaded code. I searched on google and the forum but couldn't find an answer. Thanks!

By uploading, you effectively replace the contents of the Arduino's code storage (flash). There is no going back unless you still have the original source to recompile and upload (or the compiled binary you can upload).

Thanks! :slight_smile: