STM32F469I as USB Host communicating with modem

[Matti Sillanpaa]

Posted on March 16, 2017 at 10:00

Hi.

I've got external modem that enumerates 6 virtual com ports and only one of those are available for AT commands. I've looked at the examples and the libraries and I do not quite get how to choose the com port that I might communicate. The CDC_standalone example just establishes the communication with the device, but there's no selection or anything.

Is there any examples or documentation how to enumerate the different endpoints?

[Matti Sillanpaa]

Posted on March 16, 2017 at 13:29

After digging the CDC_standalone for a while, found the iteration from usb_core.c and parsing & set functions. However it's a bit weird that there's hard coded interface selection also there. One would assume these things would be done in user functions or at least in config level.

[Tesla DeLorean]

Posted on March 16, 2017 at 15:48

Would expect specific streams to use different end-points defined by descriptors. The STM32 designs having a finite limit on those.