.. zephyr:code-sample:: usb-cdc-acm-composite
:name: USB CDC-ACM composite
:relevant-api: usbd_api
Implement a composite USB device exposing two serial ports using USB CDC-ACM driver.
Overview
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This sample app demonstrates use of a USB Communication Device Class (CDC)
Abstract Control Model (ACM) driver provided by the Zephyr project in
Composite configuration.
Two serial ports are created when the device is plugged to the PC.
Received data from one serial port is sent to another serial port
provided by this driver.
Running
*******
Plug the board into a host device, for example, a PC running Linux.
The board will be detected as shown by the Linux dmesg command:
.. code-block:: console
usb 1-1.5.4: new full-speed USB device number 28 using ehci-pci
usb 1-1.5.4: New USB device found, idVendor=2fe3, idProduct=0002, bcdDevice= 2.03
usb 1-1.5.4: New USB device strings: Mfr=1, Product=2, SerialNumber=3
usb 1-1.5.4: Product: Zephyr CDC ACM Composite sample
usb 1-1.5.4: Manufacturer: ZEPHYR
usb 1-1.5.4: SerialNumber: 86FE679A598AC47A
cdc_acm 1-1.5.4:1.0: ttyACM1: USB ACM device
cdc_acm 1-1.5.4:1.2: ttyACM2: USB ACM device
The app prints on serial output, used for the console:
.. code-block:: console
Wait for DTR
Open a serial port emulator, for example, minicom,
and attach it to both detected CDC ACM devices:
.. code-block:: console
minicom --device /dev/ttyACM1
minicom --device /dev/ttyACM2
The app should respond on serial output with:
.. code-block:: console
DTR set, start test
Baudrate detected: 115200
Baudrate detected: 115200
And on ttyACM devices provided by the Zephyr USB device stack:
.. code-block:: console
Send characters to another UART device
The characters entered in one serial port will be sent to another
serial port.
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