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!

1 Answer 1


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, 2019 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, 2019 at 17:26

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