Hello, I have seen several threads on similar topics, but none of their fixes have resolved this for me. I recently purchased an arduino due, and am trying to set up a DHT11 temperature station for it. It was in a semi-working state last night, but when i tried to update the sketch this morning, the tools>port option was greyed out. If i try to upload a sketch, it will say no device found on com6 (after IDE reinstall its now always com 1). Nothing was updated in the meantime that could have caused this. I have tried reinstalling the IDE, board manager, updating the drivers, and tried a few things in device manager since I couldn't see the com 6 port in there. The PC can still address my arduino uno just fine, and when i did a fresh install of the IDE on a PC which never had it before, the issue was not present.
For starters, plug the Micro USB port into the PROGRAMMING PORT (ATMEGA16U2) on the Due.
Plug the other end of the wire to the computer. There should be a few LEDs that light up (namely "L" and "ON").
If no light turns on (but you verify that the USB port is good), your board is fried.
If lights turn on, go open Arduino, and select Arduino Due (not duemilanov) under Tools -> Boards.
If you cannot find Arduino Due (programming port), you need to install the library.
Note, by default the library for Due is NOT installed (because Due is ARM32).
Go to board manager and install the library.
Then select Arduino Due (programming port). And select the COM port.
Also, remember: Unlike most other boards, the Arduino Due runs on 3.3V. Applying voltage higher than 3.3V on any IO pin can damage the board.