usb_cdc module AttributeError on Adafruit KB2040

[martinsram3k]

CircuitPython version and board name

Adafruit CircuitPython 9.2.4 on 2025-01-28; Adafruit KB2040 with rp2040

Code/REPL

import usb_cdc
import board


usb_serial = usb_cdc.serial

while True:
    if usb_serial.in_waiting > 0:
        data = usb_serial.readline().decode('utf-8').strip()
        print(f"Přijatá data: {data}")
        usb_serial.write(f"Odpověď: {data}\r\n".encode())

Behavior

Actual Behavior:

When attempting to use usb_cdc.serial or usb_cdc.serials, I receive the error AttributeError: 'module' object has no attribute 'serial' or 'module' object has no attribute 'serials'.

System Information:

• Board: Adafruit KB2040
• CircuitPython Version: 9.2.4
• Computer Operating System: [Windows 10]
• my board si flashing red

Description

Problem Description:

On my Adafruit KB2040 running CircuitPython 9.2.4, I am unable to initialize the serial port using the usb_cdc module. When attempting to use usb_cdc.serial or usb_cdc.serials, I receive the error AttributeError: 'module' object has no attribute 'serial' or 'module' object has no attribute 'serials'.

Steps I have taken:

Installed CircuitPython 9.2.4 on my Adafruit KB2040.
Verified the compatibility of the board and CircuitPython version.
Reinstalled CircuitPython multiple times.
Verified basic board functionality with a blinking LED test.
Performed a "factory reset" of the KB2040.
Checked the boot_out.txt file (attached below).
Tried different serial terminals and computers.
Verified that I have the USB-to-UART adapter connected correctly.
Tested bidirectional communication using PuTTY and code in code.py.
Expected Behavior:

I expect the usb_cdc module to function and allow me to communicate with the KB2040 via the serial port.

Additional information

No response

[Neradoc]

Have you perused the documentation for the usb_cdc module ?
https://docs.circuitpython.org/en/latest/shared-bindings/usb_cdc/index.html#module-usb_cdc

There is no such thing as usb_cdc.serial or usb_cdc.serials.
You are looking for usb_cdc.console or usb_cdc.data (the second one requires activating in boot.py).

Here, I have some sample code for communicating via USB serial:
https://github.com/NeraSamples/circuitpython_usb_serial

[dhalbert]

Closing because I think this has been addressed.