funny that i was thinking of starting this discussion
i searched hundred of pages many many times but could never be successful of finding the 4th code for ardunio. All others OK but not for ardunio. Either that 4th key is kept for the close end of the competition or it is just a typing error ( less possibility ). Maybe it is kept in an unexpected place ( such as a document ). I am wondering why the 4th code for ardunio is so much important that it can not be found.
I also found 2 only for arduino but that was way back December. I didn't know that there's even a 3rd clue.
I also found 3 clue for arduino, i searched almost all pages many times the 4th clue not found.
In December I found 3 pic codes, 2 fluke codes and only 3 arduino's ...
I viewed almost all, it seems that there isn't yet... ready.