Document M3Y-W USB-CDC setup

README.md

@@ -71,15 +71,24 @@ options:
   --test-baudrates                                      Runs through a list of common baud rates to see what your device supports (Or finds out what BAUD it is currently using)
 
 
-## GM65 & GM805 Barcode Scanner Specific Options
+## USB Serial Setup
 
-### Enabling USB Virtual Serial Port
+### GM65 & GM805: Enabling USB Virtual Serial Port
 You can either connect the barcode scanner via a serial port or use the built-in virtual serial port function.
 
 To use this function, you need to scan the following QR code. (You may need to manually trigger scanning the first time to do this, but once enabled, this setting is persistant until reset)
 
 ![](utility_qr_codes/gm65/enable_virtual_usb.png)
 
+### M3Y-W: Enabling USB-CDC
+The M3Y-W defaults to USB HID keyboard mode, so it will not appear as a serial port for this tool until USB-CDC mode is enabled.
+
+Scan the following QR code from the M3Y-W user guide to switch the scanner to USB-CDC mode. After that, reconnect the scanner and run the tool against the serial device that appears on your system.
+
+![](utility_qr_codes/m3y/enable_usb_cdc.png)
+
+## GM65 & GM805 Barcode Scanner Specific Options
+
 ### Factory Reset the Scanner
 To reset all of the settings back to their defaults, scan this code.