USB to Ethernet adapter

[gadget-man]

As an alternative to WiFi, I'd like to be able to connect my ESP32S3 to the network using a usb-ethernet dongle. It uses a Realtek 8152 chipset which I understand is CDC-NCM compatible. Here is the configuration descriptor:

2025-02-17 15:23:43 bLength 9
2025-02-17 15:23:43 bDescriptorType 2
2025-02-17 15:23:43 wTotalLength 80
2025-02-17 15:23:43 bNumInterfaces 2
2025-02-17 15:23:43 bConfigurationValue 2
2025-02-17 15:23:43 iConfiguration 0
2025-02-17 15:23:43 bmAttributes 0xa0
2025-02-17 15:23:43 bMaxPower 100mA
2025-02-17 15:23:43     *** Interface descriptor ***
2025-02-17 15:23:43     bLength 9
2025-02-17 15:23:43     bDescriptorType 4
2025-02-17 15:23:43     bInterfaceNumber 0
2025-02-17 15:23:43     bAlternateSetting 0
2025-02-17 15:23:43     bNumEndpoints 1
2025-02-17 15:23:43     bInterfaceClass 0x2
2025-02-17 15:23:43     bInterfaceSubClass 0x6
2025-02-17 15:23:43     bInterfaceProtocol 0x0
2025-02-17 15:23:43     iInterface 5
2025-02-17 15:23:43             *** Endpoint descriptor ***
2025-02-17 15:23:43             bLength 7
2025-02-17 15:23:43             bDescriptorType 5
2025-02-17 15:23:43             bEndpointAddress 0x83   EP 3 IN
2025-02-17 15:23:43             bmAttributes 0x3        INT
2025-02-17 15:23:43             wMaxPacketSize 16
2025-02-17 15:23:43             bInterval 8
2025-02-17 15:23:43     *** Interface descriptor ***
2025-02-17 15:23:43     bLength 9
2025-02-17 15:23:43     bDescriptorType 4
2025-02-17 15:23:43     bInterfaceNumber 1
2025-02-17 15:23:43     bAlternateSetting 0
2025-02-17 15:23:43     bNumEndpoints 0
2025-02-17 15:23:43     bInterfaceClass 0xa
2025-02-17 15:23:43     bInterfaceSubClass 0x0
2025-02-17 15:23:43     bInterfaceProtocol 0x0
2025-02-17 15:23:43     iInterface 0
2025-02-17 15:23:43     *** Interface descriptor ***
2025-02-17 15:23:43     bLength 9
2025-02-17 15:23:43     bDescriptorType 4
2025-02-17 15:23:43     bInterfaceNumber 1
2025-02-17 15:23:43     bAlternateSetting 1
2025-02-17 15:23:43     bNumEndpoints 2
2025-02-17 15:23:43     bInterfaceClass 0xa
2025-02-17 15:23:43     bInterfaceSubClass 0x0
2025-02-17 15:23:43     bInterfaceProtocol 0x0
2025-02-17 15:23:43     iInterface 4
2025-02-17 15:23:43             *** Endpoint descriptor ***
2025-02-17 15:23:43             bLength 7
2025-02-17 15:23:43             bDescriptorType 5
2025-02-17 15:23:43             bEndpointAddress 0x81   EP 1 IN
2025-02-17 15:23:43             bmAttributes 0x2        BULK
2025-02-17 15:23:43             wMaxPacketSize 64
2025-02-17 15:23:43             bInterval 0
2025-02-17 15:23:43             *** Endpoint descriptor ***
2025-02-17 15:23:43             bLength 7
2025-02-17 15:23:43             bDescriptorType 5
2025-02-17 15:23:43             bEndpointAddress 0x2    EP 2 OUT
2025-02-17 15:23:43             bmAttributes 0x2        BULK
2025-02-17 15:23:43             wMaxPacketSize 64
2025-02-17 15:23:43             bInterval 0
2025-02-17 15:23:43 I (838) CLASS: Getting Manufacturer string descriptor
2025-02-17 15:23:43 Realtek
2025-02-17 15:23:43 I (848) CLASS: Getting Product string descriptor
2025-02-17 15:23:43 USB 10/100 LAN
2025-02-17 15:23:43 I (848) CLASS: Getting Serial Number string descriptor
2025-02-17 15:23:43 00E04C3603D6```

I'm able to setup my ESP32S3 as a USB Host and obtain the above information, but I realise that I need to create a host device class, and then route LWIP via the USB Host so that my device can obtain an IP address from the DHCP server and route traffic over usb-ethernet.

Any advice on how to achieve this?

[hathach]

You need to implement host driver for the dongle

[gadget-man]

OK that's what I suspected, but I'm not quite sure where to start. Are there any examples of host drivers for other types of device that I could use as a reference point?

[hathach]

There is existing host driver for msc,hid,cdc for reference