Connecting APU board over USB-serial cable to macOS
Apple hardware doesn't come with serial ports any more, so one must get a USB adapter to connect to the APU board over cable. By default, macOS doesn't come with drivers for this adapter. To connect you need to download and install drivers.
OSX drivers for Silicon Labs CP2104
Serial-to-USB adapter is based on Silicon Labs CP2104 controller. You can find the drivers on Silicon Labs website, here:https://www.silabs.com/products/development-tools/software/usb-to-uart-bridge-vcp-drivers
Download the "Macintosh OSX (v5)" file and follow the installation instructions.
Once you have the drivers installed, connect the APU board and verify that the adapter is detected by the OS. You should see this device show up:
Connecting via screen
Once you see the device show up in /dev/ you can connect via screen like this:
# screen /dev/tty.SLAB_USBtoUART 115200
Note, you must be root to be able to connect.