ESP32-S3 USB OTG - USB Hub support?

[chase.liu]

I have a display board, there is a usb hub on the board. There is a cdc device behind the hub, and maybe more devices behind the hub in the future. I need the esp32s3(as the cdc host) to talk to the cdc device behind the hub. Is there any way to do this? Any info about the API, example, or doc will help a lot, thanks.

The communication I want works like this:
ESP32 -> usb HUB -> cdc device

[ESP_Dazz]

Hub support is still on our todo list. See the USB Host Library documentation for more details.

[nickbits]

FYI you also can't roll your own hub support because the current SDK does not let you open an endpoint for address 0, which is needed for device enumeration. I got things working up until that point and then was stuck.

[davidb]

ESP_Dazz, how far is it on the todo list?

Is there a way to implement something without having official support? Via TinyUSB or other ways

[stefro]

Also interested in the topic. Hub support could extend a lot the functionality of a single chip.
In my case I was looking to see if I can connect multiple usb webcams. If possible in another way, please let know.

Thank you!

[TVA_VAE]

Dear,

Any update yet? We also need USB hub support (to communicate to 6 devices behind the hub, if already possible).

Greetings

[ESP_Bob]

USB Hub is not supported by Host Driver now. Would you please tell us the application scenario? Which kind of device users want to connect through HUB? and how many? this will help us evaluate the priorities of this driver development

[davidb]

2 HID devices in my case. Having both mouse & keyboard is a pretty basic use case

[relevante]

USB Hub is not supported by Host Driver now. Would you please tell us the application scenario? Which kind of device users want to connect through HUB? and how many? this will help us evaluate the priorities of this driver development

Has there been any progress on this?

We are trying to determine feasibility of an ESP-based single-chip solution for our project, so I haven't started looking deeply into the SDK code yet. Our project requires connecting to multiple low speed USB devices, but I wonder about nickbits' comment back in June. Can someone from Espressif please comment on this? Is there a hard block currently in the SDK that would prevent a third party from implementing their own USB hub support? Even if we were willing to modify the available ESP-IDF code to do so?

In other words, is the present limitation in the open source ESP-IDF codebase, or in the private ESP code?

I intend to assign some resources to work on this very soon, but obviously would like to know if it's currently impossible before starting, so we can focus our efforts elsewhere if our desired functionality is currently impossible.

Thank you.

[ESP_Sprite]

Hi! I poked some people responsible for the USB stack; hope they will chime in. All the code that handles USB is entirely in the open-source part of ESP-IDF (with the exception of the CDC-ACM driver code in ROM, but host mode doesn't use any of that and even device mode only optionally uses that) so you should technically be able to implement it. I think nickbits tried to implement hub support without changing ESP-IDF and that indeed is not possible at this moment.