How to Format a USB Drive to FAT32 on Mac

diskutil list
sudo diskutil eraseDisk FAT32 SA MBRFormat /dev/disk2

SA // New disk name

or use https://www.sdcard.org/downloads/formatter/index.html

Setup Serial Port VM VirtualBox

for macOS, Unix

Enable in Virtual Box

Ports -> 

Host Device:
/dev/tty.wchusbserial1420

Important! In the guest system install drivers for the device that will be used with the port.