2019-04-07 04:33 AM
Hello,
I understand that many STM32 support USB OTG, so they can be USB hosts.
What if I want to connect more than one device? Can I connect a USB hub and control several devices at the same time?
Solved! Go to Solution.
2019-04-15 09:09 AM
Maybe a little bit out of you requirements, but please note that MPUs of STM32MP1 Series embed an USB high speed Host (named USBH) with 2 ports and PHY, and, if you want more, fully support USB Hub (soldered or external box) under Linux without any 3rd party license (as an example, there is already a 1 to 4 hub on STM32MP157C-DK2).
Btw, the provided USB camera demo on the discovery work through internal Hub.
2019-04-07 05:00 AM
Yes, but the USB host stack coming with Cube/CubeMX does not support hub(s). You would need to resort to 3rd party libraries, or write your own.
JW
2019-04-07 10:08 AM
Segger's USBH library manual says that Synopsys controllers in F and L series have a bug with low-speed devices connected thru a external hub:
https://www.segger.com/downloads/emusb-host/UM10001 19.3.2.1
(show stopper for me because I use low-speed HID devices).
Segger's support states that at least some H series MCUs do not have this bug (I haven't tested).
Hope this helps.
-- pa
2019-04-07 11:15 PM
Wow, ok. Thanks for the warning!
Low speed is 1.5 Mbit? So if I'm using a USB camera, we should be fine?
2019-04-08 02:55 PM
> So if I'm using a USB camera, we should be fine?
If you also use Segger's or other good library with hub support - maybe.
ST's free "middleware" does not work with hubs.
-- pa
2019-04-10 03:58 AM
This is really important. Thank you!
2019-04-15 09:09 AM
Maybe a little bit out of you requirements, but please note that MPUs of STM32MP1 Series embed an USB high speed Host (named USBH) with 2 ports and PHY, and, if you want more, fully support USB Hub (soldered or external box) under Linux without any 3rd party license (as an example, there is already a 1 to 4 hub on STM32MP157C-DK2).
Btw, the provided USB camera demo on the discovery work through internal Hub.
2019-04-15 02:38 PM
Thanks! I was actually thinking in that direction.
Where do you see the USB camera demo?
2019-04-15 11:34 PM
please have a look to https://wiki.st.com/stm32mpu/wiki/Getting_started/STM32MP1_boards/STM32MP157C-DK2/Let's_start/Use_the_demo_launcher
and https://www.youtube.com/watch?v=M-oodDBpETI
2019-04-16 11:51 AM
May god bless you with many sons.