When I connected my Arduino Nano 33 IoT to my 2017 iMac (Ventura OS), the USB port did not show in the Arduino IDE port list, even after double-clicking the Nano reset button to put it in the right mode. Installing the special CH34X device driver on the Mac for the USB port did not work either.


1 Answer 1


This is a common problem as judged by online questions. The most common solution seems to be to install the special CH34X device driver on the Mac for the USB port, but I'm suspecting many people actually have the same problem I did.

Have you heard of a “charge only” USB cable? I was skeptical, but I discovered that four of my six USB-to-microUSB cables were charge-only! If you want to communicate data, for example connecting your computer to an Arduino microprocessor to program it, the charge-only cable will not work.

How to tell the difference? There are four wires in the data-capable cable. The outside two on the connector are for charging and the inside two are for data. If yours is missing the inside connectors, then it’s charge-only. But if it has them, it still might be charge-only. Use a meter to do a continuity check to test if those middle connectors are connected. You’ll need to use a little fine wire to get inside the little micro-USB connector to make contact, and you’ll probably need somebody to help you by holding one end in contact.

As soon as I switched to a data-capable cable, the Nano USB port showed up in the IDE list! (After double-clicking the Nano reset button).

After I got it working, I uninstalled the special driver I had installed, and it continued to work.

Thanks ptillisch on Arduino Team!

  • This is a common issue with several Q+As already in the system. arduino.stackexchange.com/a/19856/37523
    – VE7JRO
    Mar 15 at 18:45
  • Yes, I looked at the others and they were either locked for further addition, or not quite appropriate.
    – Ted Toal
    Mar 18 at 17:55

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