Add USB Serial to your Raspberry Pi Zero W
From Lofaro Lab Wiki
This tutorial is based on: https://learn.adafruit.com/turning-your-raspberry-pi-zero-into-a-usb-gadget/serial-gadget
Prerequisites
You must have the following:
- Raspberry Pi Zero W
- Raspbian Jessie (or Jessie Lite) installed after the May 2016 release
- USB Cable
Steps
Step 1. Edit config.txt & cmdline.txt
Insert the SD card into your computer. Use a text editor to open up the config.txt file that is in the SD card post-burn.
Go to the bottom and add the following to the last line:
dtoverlay=dwc2as
Save the config.txt file as plain text and then open up cmdline.txt After rootwait (the last word on the first line) add a space and then:
modules-load=dwc2,g_serial
At the time of writing, this is the full cmdline.txt contents (in case you need to start over). Note it is one very long line
dwc_otg.lpm_enable=0 console=serial0,115200 console=tty1 root=/dev/mmcblk0p2 rootfstype=ext4 elevator=deadline fsck.repair=yes rootwait modules-load=dwc2,g_serial quiet init=/usr/lib/raspi-config/init_resize.sh