Port number jumping when uploading

Development Tools IDE 1.x
1

Weirdly, on both my computer, and different boards, when I try to upload a sketch, say blink, via a port, say COM2, it jumps up by one, to COM3, seen both on the status bar in arduino AND on on Device Manager.
The message ' avrdude: ser_open(): can't open device "\.\COM3" ' then comes up, sometime with a casn't find file message and sometimes with an access permission message.

Then the port drops back down to COM2.

I've reinstalled Arduino and tried different versions.

I've tried changing the port number via Dev Manager.

On one computer I can get an upload if it is the very first thing I do on opening.

Help please?

2

I have seen that as well, try a different arduino and I believe the problem will vanish. I have not looked into what the problem is so I cannot fully answer your question but you are far from the only one.

3

This is normal behavior on some Arduino boards. But you have NOT told us what one you have.

1 Like
4

The problem has occurred on two Unos (called Elevens), a Leonardo and an ATMega. On a desktop machine and a laptop, two different brands running Win10.

It also happens using Visuino and S4A (during the attempt to upload the necessary firmware).

I'm not a newb, and have successfully used arduino for about 8 years, on projects ranging from telescope autofocussers to cnc foam cutters.

I've dragged out an old laptop and installed 1.8.18 on it and it seems to be working okay. Perhaps it is a driver problem brought on by a Win10 update?

Definitely not 'normal behaviour' in anything I've ever done in the past, on any boards, or other COM devices!

5

Well then, your LEONARDO (That does do this) is broken. And I doubt it's Windows 10 updates as I've got 15 Windows machines here all with multiple Arduinos connected up, all up to date and fully working! It must be some other software on your system, or possibly a driver!

6

Okay missdrew:

  1. ALL the boards I have do this- not just the Leonardo.
  2. The Leonardo just uploaded happily on the older 1.8.18,working fine. So did the Uno. Haven't bothered trying the others
  3. Happy you feel it isn't a Win10 update issue, but then, what? Hunting down some individual driver by going through the entire Dev Manager list? I hope not!

Thanks anyway.

7

All I can tell you is it works here!

8

It seems that ther are tools to assign fixed COM port numbers to specific devices.

An example that I havn't tested it yet, test at your own risk

9

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