UCPD G0 Disco board in SPY mode doesn't show up as a USB device (STM32G071B-DISCO)

[Brenden_PLUS]

So i have the stm32G0 usb-c disco board.

https://www.st.com/en/evaluation-tools/stm32g071b-disco.html

I've flashed the latest USBPD_Analyzer software on the device and i have the latest UCPD monitor project. 

The semi problem is that it's kind of frustrating that in SPY MODE by default the mico doesn't show as a USB device.  I only see the usb micro usb connection when i'm in Snk Mode.  Is there a reason why in spy mode the USB connection to the PC from the micro doesn't show up?

So what i have to do is.  Start in Snk mode.  Connect to the PC via the micro usb connector and connect to the UCPD monitoring program.  Then i can switch to SPY MODE then i can attach my devices to it.  Which can kind of be flakey some times.

[Brenden_PLUS]

Connection

So the STMG0 doesn't actually connect to the USB device.  It has a uart connection that talks to the programing STM32F0 chip.  

Read switch

Here's the read switch.  It does some kind of protection.  Just not sure what it does.

Code

You do a HAL_NVIC_SystemReset. Every time there a change in DOOR_SENSE_PIN.

But i don't really see where the uart comm's happen.  

[FBL]

Hi @Brenden_PLUS 

Indeed this workflow is required because SPY mode is a passive sniffer role and doesn’t present itself as a USB device to the host PC. It is designed to provide trace data for debugging purposes. It's mentioned in User manual, only the trace is available.

Also in wiki, if the GUI responder is not activated (_GUI_INTERFACE compilation switch) in the embedded firmware (It is the case for the STM32G071B-DISCO, when the blue door is open = spy mode), the debug information are available (UART through VCP of the STLink, and the compilation switch _TRACE activated) you may still see the trace in UCPD monitor by clicking on the Trace button in the bottom right corner.

[Brenden_PLUS]

So what i don't understand still is why in the Spy mode why it doesn't show up as a USB device.  

I have to do this sequence

1. Start like this
   1. Switch closed
   2. usb dev board plugged in
   3. usb micro plugged in
2. Connect via the software
3. Then open the switch
4. Then plug in the USB C device into the dev board.

In my mind the steps should be

1. Have everything connect
2. Connect to the software

This isn't a big deal its just that the software or my pc fails and i need to restart the software.  So i have to unplug and reset everything way more then i think i should.   

[FBL]

Hi @Brenden_PLUS 

The firmware simply never brings up the USB device stack neither in spy mode nor in sink mode. Windows never sees a USB device, and in spy mode there is nothing for the UCPD Monitor to connect to over USB.

What you are expecting is not feasible with this context.

[Brenden_PLUS]

So i made a video of what the problem is i'm having.  

https://www.youtube.com/shorts/p3VMNoLNCv8

Put yes i know the STM32G071 does not have a usb connection.  But it does have one to the programmer.  The programmers USB talks to the USB_UCPD app.  This talking only works initially when the device switch is closed.  

So that's the question i'm trying to solve.  

[FBL]

Hi @Brenden_PLUS 

Thank you for your feedback!

I have submitted an internal ticket to dedicated team for further explanation when reconnecting device (226988).

In my understanding, negotiation sniffer should be disabled whenever reconnected to SPY mode.