TUSB320

> I would like to use the TUSB320 USB-C controller with I2C to detect my STM32F4 as a device.

Elaborate. Draw a block schematics, how do you have TUSB320 connected to STM32F4. Explain the expected funcitonality.

JW

Thanks for your reply @Community member​  !

Thats the way it is connected. SDA and SCL goes to I2C3 of the STMF401RE. The expected functionality is that when I plug the USB-C connector in the USB-C interface of my computer that it gets detected automatically through CC1 and CC2. It shall run as a device with all "default settings", I dont need anything special since I just want to use it for communication. The STM32F4 is powered through VBUS and I already tested it with the use of an USB-C to USB-A connector. Everything works, but when I plug it into the USB-C port of my computer nothing happens. How do I have to set up the TUSB320 so that my computer recognize the STM32? Like you see I am pretty new to USB-C communication.

USB does not communicate through CC1/CC2 but through DP/DM. Do you have them connected to the USB-C connector (both sides)?

JW

@Community member​ 

I know that it communicates through DP/DM, but CC1/CC2 is used to set up the connection (tell the host(my computer) that the STM32 is acting like a device...stuff like that), isnt it?

What and when does the TUSB320 needs to transmit that my computers usb-c port will recognize the STM32 as a usb-c device?

I am using the STM32 as a USB CDC device, and its working when I connect it with my computer over a USB-C to USB-A adapter and plug the A side into my computer but it does not get recognized when I plug it into my USB-C port (without any adapter in between).

Attached is my usb-c connector.

I am not looking into the standard now, but basically a device does not need to communicate through CC1/CC2 for the basic functionality; all it needs is to connect a certain value pulldown (5.1kOhm IIRC). The TUSB320 probably already has that in place by default, check in its DS.

Note, that there are several types of USB-C cables around, both by standard and by folks usually ignoring the standard, and I know of "charge-only" cables which don't have any of the data wires inside.

JW