Couldn't find a Board on the selected port. Check that you have the correct...

Hi Arduino Community,

I am a novice level programmer working on the Blimpduino 2, which is an Arduino Zero board.

The first few times I uploaded code onto the board, there were no problems. However, since yesterday, every time I try to upload onto the board, the error message above comes (“Couldn’t find a Board on the selected port. Check that you have the correct port selected. If it is correct, try pressing the board’s reset button after initiating the upload”).

In other Arduino forum threads, I see that the most common problem is that the “Port” section in the “Tools” tab is grayed out. However, my problem is not the case. Here are the sequence of events that happen (in my understanding) when I press the upload button (with the board and port initially connected and recognized):
1.) Code is verified
2.) Code is compiled
3.) CPU Reset
4.) Upload onto board

My hypothesis is that when the CPU resets, the board is then disconnected momentarily, and the Arduino IDE doesn’t register the port, even though after the upload, it shows the computer is connected to the Arduino Zero and connected to the COM3 port.

One thing that struck me as odd is that I see multiple instances of COM3 ports selected. I attached an image of this which includes the error message at the bottom.


This is a known bug in the Arduino IDE:

It actually is two bugs:

  • Duplicate Tools > Ports menu entries
  • Spurious upload failure

They might seem related because they are triggered by the same action, but they are otherwise unrelated to each other.

The latter bug has already been fixed in the hourly build of the Arduino IDE:

The latter bug is fixed in the beta build of the Arduino IDE. However, this is only a cosmetic issue so I recommend that you use the more stable hourly build and just ignore the duplicate ports.