ESP32 Forum

For anyone else looking to do similar, I now have a version of cdc-ecm-host working for RTL8152 devices:

https://github.com/gadget-man/cdc-acm-host

It works for a basic ping, still need to test for other network events and it needs some tidying up, so PRs welcome!

Hi, thanks for sharing.
I have RTL8153 device, but sadly it is using 0xFF driver, so it is not recognized.
I also tried with USB-NCM device on esp32-p4, but it also is not working, even if its recognized.

I believe that both RTL8152 and RTL8153 have both primary (0xFF) and Secondary configurations (CDC-ECM), so it should be working. I've just tested with a Belkin usb-c to ethernet dongle here which uses the RTL8153 chipset and was able to get an IP address over DHCP and then ping the device.

Could you test our example script and let me know what console output you get, so that we can look into whether it's a device-specific problem?

Sadly the one i have, from waveshare, is using 0xFF interface too:

That looks as though it's the details for bConfigurationValue 1. On Realtek 8152 the cdc-ecm interface is on bConfigurationValue 2. Have you enabled `CONFIG_USB_HOST_ENABLE_ENUM_FILTER_CALLBACK` and captured the callback to set the second configuration?

Can you post the full device and config descriptors for your device, just to check that you have `bConfigurationValue 2`

Also, have you tried the sample code from my repo to test it?

I'm trying to have the ESP32S3 pose as USB-C-Ethernet adapter for the use with iOS. With the USB-NCM example I get an Ethernet device on iOS and so far it looks good. What's the difference between USB-CDC-NCM and USB-CDC-ACM though and why would it be beneficial to use one over the other?

In the end, on the ESP32S3 side, I'd like an esp-netif to be initialized, so that I can run a DHCP-SERVER and some additional TCP services. Can I do that with NCM and ACM alike?

CDC-NCM is network port over USB
CDC-ACM is a serial port over USB, like regular UART

If you want, here is simple example with my usb-netif component. This example is for P4, but it will also work on S3
https://github.com/esp32-open-source/usb-netif-example

You actually dont have to use my component anymore, because espressif simplified and provided very good API and example, which i posted earlier.
My component is just a C++ wrapper, which can initialize usb-netif with just one of code with default settings.
From my experience simpler than espressif usb-netif is only blink example. Everything is configured with just a few lines of code, less than a 10 probably.

Coming back to that after some months. I'm having problems with USB-NCM when talking to Apple devices. Switching to ECM/RNDIS seems to help with initial detection (it gets a DHCP address), but it doesn't properly survive iOS device suspend/resume.

UPDATE: Actually some tweaking to the USB-NCM makes DHCP negotiation at plug/replug work, but it also suffers from not surviving iOS device suspend/resume.

Note that it works just fine for Linux, but as much as I'm inclined to drop it as an "Apple-specific problem", I need to get this working.