Running Multiple USB CDC ACM ports simultaneously

RE: Running Multiple USB CDC ACM ports simultaneously

narangmayank — Tue, 04 Feb 2025 10:16:44 GMT

I'm not sure about other USB class but CDM ACM require 2 IN endpoints per instance. So max we can have is 3 only. I'm closing this ticket since I got the answer, Thanks!

RE: Running Multiple USB CDC ACM ports simultaneously

Kenneth — Thu, 30 Jan 2025 14:03:32 GMT

The hardware only have a limited number of endpoints available, but I would expect it could support more than 3, is there any other USB class than CDC?

Kenneth

RE: Running Multiple USB CDC ACM ports simultaneously

narangmayank — Thu, 30 Jan 2025 12:50:16 GMT

I changed back the console to uart, got this error output which says failed to enable usb, I think thats why I'm not able to see any COM port.

*** Booting nRF Connect SDK v2.8.0-a2386bfc8401 ***
*** Using Zephyr OS v3.7.99-0bc3393fb112 ***
[00:00:00.363,525] <inf> cdc_acm_echo: Starting App...
[00:00:00.363,586] <err> usb_nrfx: invalid endpoint index/address
[00:00:00.363,586] <err> usb_nrfx: invalid endpoint index/address
[00:00:00.363,586] <err> usb_nrfx: invalid endpoint index/address
[00:00:00.363,616] <err> usb_nrfx: invalid endpoint index/address
[00:00:00.363,616] <err> usb_nrfx: invalid endpoint index/address
[00:00:00.363,616] <err> usb_nrfx: invalid endpoint index/address
[00:00:00.363,647] <err> usb_nrfx: invalid endpoint index/address
[00:00:00.363,647] <err> usb_descriptor: Failed to validate endpoints
[00:00:00.363,647] <err> usb_descriptor: Failed to fixup USB descriptor
[00:00:00.363,647] <err> usb_device: Failed to configure USB device stack
[00:00:00.363,677] <err> cdc_acm_echo: Failed to enable USB

RE: Running Multiple USB CDC ACM ports simultaneously

narangmayank — Thu, 30 Jan 2025 12:28:50 GMT

Hi Kenneth

This doesn't help. Are you aware of any such limitations of emulating multiple COM ports?

I'm using following usb conf,

CONFIG_STDOUT_CONSOLE=y

CONFIG_USB_DEVICE_STACK=y

CONFIG_USB_DEVICE_PRODUCT="Zephyr CDC ACM sample"

CONFIG_USB_DEVICE_PID=0x0001

# CONFIG_USB_DRIVER_LOG_LEVEL_ERR=y

# CONFIG_USB_DEVICE_LOG_LEVEL_ERR=y

CONFIG_SERIAL=y

CONFIG_CONSOLE=y

CONFIG_USB_CDC_ACM=y

CONFIG_UART_INTERRUPT_DRIVEN=y

CONFIG_UART_LINE_CTRL=y

CONFIG_USB_DEVICE_INITIALIZE_AT_BOOT=y

Regards,

Mayank

RE: Running Multiple USB CDC ACM ports simultaneously

Kenneth — Thu, 30 Jan 2025 11:54:10 GMT

Hello,

I havent tried it, but if you enable:

CONFIG_LOG=y

CONFIG_LOG_MODE_IMMEDIATE=y

CONFIG_RESET_ON_FATAL_ERROR=n

There is no error or fault?

Kenneth