USB Host "No registered class for this device."

[Flankiste]

Hi, i'm working on connecting a multimeter to an stm32f2 via USB (STM32 as a HOST). The goal is to send SCPI commands to it (I easly did it in python just to chek the correct behevor of the multimeter).
I implemented the USB Host lib but after few hours of debugging i cant figure out how to set the active class... (phost->pActiveClass != NULL) return false and i get "No registered class for this device". I have setup CDC in cubeMX but doesn't seems to work).
I use the USBH_CDC_Transmit to send command to the multimeter but since the USBH_UserProcess state machine never reach APPLICATION_READY state it's not even a thing (i tryed sending commands in APPLICATION_START state but no success either).

I get the folowing output with max lvl of debug :

USB Device Connected
USB Device Reset Completed
PID: ea60h
VID: 10c4h
Address (#1) assigned.
Manufacturer : Silicon Labs
Product : METRIX MX5060
Serial Number : 10003926
Enumeration done.
This device has only 1 configuration.
Default configuration set.
No registered class for this device.

Regards,

- Flankiste

[FBL]

Hi @Flankiste 

Did you refer to the example provided here ? Do you use a reference board? You may need to attach minimum firmware to replicate the issue or attach a USB traffic using USB analyzer or sniffer.