I'm trying to connect to a development board using a serial-USB adapter, and can't find the serial port on my Mac.

I tried ls /dev/tty.* and ls /dev/cu.*, and nothing relevant shows up on my Mac. I tried on a friends Mac and it does show up!

This must be because I had installed VCP / FTDI drivers in the past on my Mac (can't remember which, but there were a few), which must be interfering. I tried deleting the serial drivers .kext files in /System/Library/Extensions/ and restarting, but that didn't work. I also tried reinstalling these drivers and restarting, but that didn't work. I've tried 3 other driver sources and that also didn't work.

Also, the device doesn't show up in setting > Network. Running Mac OS Mojave on both PCs.

Help would be much appreciated!


You can open System Report and check under USB to see if your USB device was found and initialized.

In terms of device files, you'll want to search for tty* and cu* - do not include the dot.

An easy way to spot the correct device is to run first:

find /dev > list1

then plug in the serial-USB adapter, and run:

find /dev > list2

and then finally:

diff list1 list

then the name of the new device for the serial-USB adapter should be shown.

  • I can see the device listed under USB devices in System Report with product ID, vendor ID and serial number. But I still don't see anything when I run just tty* or cu* or diff the lists. – Graham Sep 7 '19 at 16:23
  • You’ll need to tell us the actual IDs before we can help you more. Sounds like you haven’t got the appropriate driver installed. – jksoegaard Sep 7 '19 at 17:26

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