SparkFun Forums

[fetchen]

I use the SAMD21 mini in many projects. I have a SAMD21 board where I have lost the primary COM port that is used for data I/O on a Windows 10 PC. After losing the primary port, I can still program the device by double clicking the reset button to manually open the secondary programming port. But after uploading a program, the secondary port closes and the primary port does not re-open. The program runs, there is just no way to access it via a USB port. Cycling power or closing all Arduino windows or rebooting the PC does not bring the port back. Loading the basic Blink script does not bring the port back. When the board is plugged into the Windows PC, the Device manager shows that a COM port opens, but it is a duplicate port number for a COM port that is already open over a Bluetooth link (port 4) and not the usual port number assigned to that particular board (port 11) on that PC, and the Arduino IDE does not recognize the SAMD21 device. The same PC recognizes other SAMD21 boards correctly.

I tried a second PC, and it does recognize the primary SAMD21 COM port for the board that the first PC fails to recognize.

Any ideas how to fix the problem?

[fetchen]

Going into the Windows Device manager and manually assignig the old port number under <Port Settings<>Advanced><COM Port Number> that used to be assigned to the SAMD21 board seems to fix the problem.