Upon plugging in a USB CDC ACM virtual COM port device into a Linux machine, the OS will automatically enumerate the USB device successfully, and a new object should show up as:
/dev/ttyACMx
(where ttyACMx is usually ttyACM0, but could be some other number such as ttyACM1, if some other ACM device is already attached to the machine).
To determine the exact number value of “x”, a procedure like follows can be used:
1. Open a console.
2. Make sure the USB device has been plugged into the machine.
3. Type: lsusb
4. You should see a line like: Bus 005 Device 004: ID 04d8:000a Microchip Technology, Inc.
5. Type: modprobe cdc-acm vendor=0x04d8 product=0x000a
6. Type: dmesg
7. You should get the status, showing the ttyACMx value, ex: cdc_acm 5-1:1.0: ttyACM0: USB ACM device
Once you know the ttyACMx value, applications and terminal programs (such as GtkTerm) can interface with the USB serial port by configuring them to connect up to the /dev/ttyACMx object.
MLA - USB Library Help Version : 2.16
![]() |