MacOS Catalina 10.15.7 USB Port Recognition Uno R3

Hi guys,

since some days I search the whole Web for a solution, and I stuck! On my two macs, running Catalina, the Uno R3 board has no USB communication with the computer. This board uses, as far as I know the ATmega USB components. It would be great if someone could help to fix the problem - I imagine that I am not the only one having this combination of OSX and Arduino board.

Many thanks and best regards, Vlad

I'm not a Mac user so probably can't really help. Question I have if it used to work in the past?

What does the equivalent of Windows Device Manager say (I guess something like dmsg and lsusb) when you connect the board?

Yes, it worked in the past. There is a tool like de Windows Dev Manager - since OSX Catalina it does not show the driver active, therefore the Uno is not recognised when connected to the Mac. It looks like a MacOS I wonder if other people had it too since OSX Catalina 10.15.7...

I just want to bump this since I’m having the exact same issue with the same version of Mac OS. I’ve opened an issue on github since now it is clear I’m not the only one experiencing this. I would like to know if there are any workarounds though. I’m happy to supply information to anyone willing to help.

What I know so far:
Serial communication does not work for both the Uno (OP) or the Mega (Me).
The Arduino does show up in the system report under USB.
The port does not show up when running “ls /dev/su*” in terminal.
It does not work using both a direct connecting with a USB B/C cable, nor does it work with a connecting to a USB A Hub, which itself is connected to the USB C port of the computer.
I have an AtMega16u2 chip to communicate between the usb and the microcontroller, so drivers shouldn’t be the issue (I don’t think, could be wrong about this)

I could connet to my arduino nano (ch340) with changing the usb adapter (USB-A to USB-C) from 3rd party to Apple one on 10.15.7. I don't know why?

I tried a total of five (5!) different USB third party cables... Arduino Uno requires a USB-B cable - I could not find such an original Apple cable though...

Maybe the idea would be to buy another Arduino board to work with, which works with Catalina? I am happy about any feedback about which board works fine with Catalina 10.15.7!

oh, my...I'm using macbook pro 2020, which has usb-c port only. so I use the adapter converting usbc to usba (, and use the cable converting usba to usb-mini too. My mac doesn't recognize my arduino nano with the 3rd party adapter (c to a) , but do with Apple original one.

About one or two weeks ago, it was ok with 3rd party one.

Thanks, ke_takahashi!

meanwhile I changed my computer and try desperately now to connect the Arduino Uno R3 to the USB-C of a MacBookPro with M1 processor and OS X Big Sur 11.1. It does not work with any 3rd party USB adapter, I should therefore try with the original Apple adapter...