The board can be found on com3 on Windows 7, but it cannot be found on Mac Monterey, it only shows a "/dev/cu-serial0" on Tools -> Port.
In system info USB section, a "USB Serial" is shown and hidden when plug and unplug the USB cable.
I tried to install driver CH34xDriver, but it also failed.
How to fix it? Thanks.
I'm not a Mac user.
Did you try to upload over /dev/cu-serial0?
Which arduino? Is it really a UNO (official one?)
Which Mac (USB C port? M1/M2 apple processor?)
If the /dev device does not work and If you have an external USB hub, try going through the hub and make sure the usb cable is of good quality
@J-M-L
uhhhh, I think it's a clone Arduino UNO. Could a clone board cause this problem? Arduino is open source, so I thought Arduino should work on both boards. 
Mac has a Intel processor. I think the cable is good because it works on Windows system.
No. Arduino cannot work with this port.
Which serial component is in your clone?
@J-M-L is asking about the chip at the right bottom in the below snip. It's definitely a clone based on that chip (and the printing on the board).
So my board doesn't work with Arduino on Mac? then I need to buy an official one.
As far as I know, it should work but maybe not out of the box. As said, I'm not a Mac user; you will have to wait till @J-M-L comes along again for more advice.
There were driver discussion for M1 based macs and CH340 chips
See there
I had tried to install CH34x before asked for help here, no luck it failed to work.
According to the tutorial, the Vendor ID was correct in system info, but when type command "ls /dev/tty*" in terminal , it did not give the correct port “tty.wchusbserialx” in list.
Can I skip this annoying steps to make it work directly on Mac if I use an official board?
Did you make sure you allowed identified developers in security preferences? Seems this guy made it work mac os - Is there an Apple Silicon (M1) driver for CH34x devices? - Arduino Stack Exchange
A regular UNO uses an FTDI chip and the driver should be built in for that
A regular Uno uses a 16U2 
A regular Nano uses the FTDI232.
You are of course right (should be built in as well and not require an additional driver/kernel extension )
The drivers had been allowed to install in security preferences, still not work. FTDI doesn't work either.
I think I need to try an official board.
Thanks for the replies.
I am working with an official Arduino Nano and a Nano 33 IoT.
I started out with the IoT board and learned quickly that you need a quality cable that supports both power and data, not just data. Specifically it seamed that it needed to be OTG (On The Go) compatible. The other thing that was needed is a CH34 driver. With an install of the ch34xser_macos) driver that is noted earlier, and the OTG cable, the Nano 33 IoT works with my MacBook Pro with the M1 Apple Silicon.
Now I am trying to get the regular Nano to work. The first cable that I bought claimed to be OTG, but I had no luck getting it to work (could not even get power to the Nano). Then I bought a second cable that gets power to the Nano, but the upload reports that the port cannot be found (the port shows in System Information). Now that I have power but no data I am trying to figure out if it is a cable or driver issue with the different Nano. Note that the cable used for Nano and Nano 33 IoT are different (totally agree with EU push for only one cable type) or this would not be such a mystery.
Does anyone know if the driver needed is different between the Nano and the Nano 33 IoT?
Yes they are different
The traditional Nano uses a Mini-B USB cable which data lines connect to the on board FTDI USB-to-TTL Serial chip which is connected to the processor (and pins 0 and 1).
The Nano 33 IOT connects with a micro USB cable and uses Native USB capabilities présent in the SAMD21 Cortex®-M0+ Processor. The UART function is separate.
You could try to find and external, powered USB C to USB2 hub to connect to your Mac and connect the arduino from the hub. (That will protect also your Mac ports against possible mistakes and short circuits you could create when tinkering)
I don’t think the OTG thingy is needed. An OTG or On The Go adapter (sometimes called an OTG cable , or OTG connector) allows you to connect a full sized USB thumb drive or USB A cable to your android phone or tablet through the Micro USB or USB-C charging port.
I have connected directly à uno to a M1 Mac using an USB C to USB B cable and all worked fine with no driver needed.
Thanks @J-M-L ,
My son, who is much more literate in these things, let me know that the OTG cable is likely the wrong cable as it could be a single direction type of cable. So that is out of the spec.
Good to know about the powered USB hub, and the idea of protecting my laptop ports. Going to take care of that right away.
What I find interesting in my case is that the virtual port shows up when I plug the Nano in (actually there are two ports) but unlike with the Nano 33 IoT the ports do not list the Nano. You can see from the image below the Nano 33 IoT connected, and the last two ports show up for the Nano.
I am in the process of trying the FTDI drivers to see if that changes anything. Perhaps the powered hub would be more successful.
I don't think you need ch34xser_macos
which version of macOS are you running on your M1?
