How to make STM32l475 work in USB host mode

[Julian Winpenny]

STM32l475 USB host USBH_UserProcess() not progressing to HOST_USER_CLASS_ACTIVE

[Tesla DeLorean]

Not really my thing, have you tried the examples, do they work?

STM32Cube_FW_L4_V1.12.0\Projects\B-L475E-IOT01A\Applications\USB_Host\MSC\readme.txt

[Julian Winpenny]

I've not tried that. Where do I download the examples from?

[Pavel A.]

Try this:

1. In your CubeMx settings, enable maximum debug level for USB
2. Make printf work somehow - print to UART or ITM trace and so on.
3. Run the program, then plug in some USB device.

There should be debug messages from USB host stack when the devices are enumerated, even if there's no any class module that supports them. So you will see whether the USB core works.

-- pa

[Tesla DeLorean]

If you're using CubeMX they'll be under your repository directory (see Help -> Updater Settings)

Or pull the file/archive manually

https://www.st.com/en/embedded-software/stm32cubel4.html

[Julian Winpenny]

Pavel,

I tried the extra debug, but I still only see "USB Device Attached"

[Pavel A.]

> but I still only see "USB Device Attached"

This means that enumeration does not start properly. Maybe you do not provide enough voltage to the device.

-- pa

[Chensie]

Hi,

If you use USBH_Process() as Host Background task?

[Julian Winpenny]

Chensie,

As I'm using FreeRtos USBH_Init() already creates a thread for USBH-Process()

[Julian Winpenny]

I think the problem is the USB low level driver was not included by STM32CubeMx

These (and others) are missing functions:

USBH_LL_Init(phost);

USBH_LL_Start(phost);

[Julian Winpenny]

These are now in USBH_Conf.c

USBH_LL_Init(phost);

USBH_LL_Start(phost);

Still no enumeration