I am not able to program my second arduino because they both use the same com port. In other words this picture says it all:

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In order to upload my sketch I have to disconnect one arduino. How can I tell windows to use a different COM port?

It will be nice if I do not have to disconnect one arduino evey time I want to upload a sketch. I already restarted my computer and I get the same problem.

  • 4
    Can't you just choose another port in the port properties? It's been a while since I futzed in windows device manager...
    – Majenko
    Jan 26 '21 at 22:39
  • 1
    That's the answer thanks Majenko
    – Tono Nam
    Jan 26 '21 at 22:49
  • 15
    Never in my life have I seen that Windows allocates the same COM port number to two different devices.. weird Jan 26 '21 at 23:07
  • 1
    @MaximilianGerhardt The only explanation I can think of is that the two UARTs are completely identical and windows can't tell them apart at all. Counterfeit FTDI chips are known to clone hardware serial numbers. Windows also usually remembers the COM number a device had when it was last seen on a particular USB port, but it usually assigns a different COM number by default even for the same device if you plug it into two different USB ports. It could be that a cloned serial combined with a first-plug while the device['s clone] being already plugged in led to this COM port doppelganger...
    – J...
    Jan 28 '21 at 4:10
  • @J... the cloning thing makes a lot of sense. I just recalled only one of my Arduinos would change port numbers when connected to different ports, and I thought that was the dead one. It also happened to be original. Feb 2 '21 at 18:36

I did not knew I could change the port on windows. This is how I did it thanks to @Majenko's comment.

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