We've designed a board that uses the same chipset (16U2>SAM3X) as the Due board. The problem we have is that we can't programme the SAM via the 16U2 USB port. However, if we wire (TX, RX, ERASE, RESET, Ground) the 16U2 on the Due board to the SAM on our board, all is well.
It would appear that the problem is with the firmware in the 16U2s we are buying (from Mouser - the date codes show they are recent devices). I've spent some time searching for answers to this issue and have tried (with FLIP) programming later versions of firmware into the 16U2, but the latest file I could find dated from 2013. Has anyone had a similar experience or does anyone know where the current firmware can be found? Or am I missing (not for the first time) something blindingly obvious? Thanks in advance for any replies.