Hello josemiguel.
Had a similar problem, but then with COM3. Sometimes it loads, most of the times not … very frustrating. It seems as if PlatformIO is having some kind of control over some (lower numbered) COM ports, which seem virtually free, but are in fact not really free. The user cannot identify these port reservations (I would appreciate if someone can confirm this). Hard to find solutions on the internet, though I managed to solve it as follows:
- In device Manager, under “Ports (COM & LPT)”, right click on the Silicon Labs one
- go to “Properties” - “Port Settings” - select “Advanced”
- In the “Advanced Settings for COMx”, select a COM port > 10, whioch is free (in my case I selected arbitrarily for COM17)
- Click “OK” to close “Advanced Settings” and 2nd time "OK to close “Properties”
- In “platformio.ini” add a line 'upload_port = COMx (where x was 17 in my case). To my belief this setting in ‘platformio.ini’ is not a requirement, though it does noet hurt
- Unplug the USB from the PC, re-plug it in and check that the Device Manager is indicating the correct COM port.
This worked for me without any problem up to now. I would be glad however to learn more on this topic and would be greatful to learn why COM3 is not giving the same positive response.