Using STM32CubeMonitor-UCPD app with STM32G071B-DISCO board

[RZitz]

Hi,

I am trying to use the STM32CubeMonitor-UCPD app in combination with the STM32G071B-DISCO board to analyze traffic running over an USB-C power delivery line.

In order to trace I need to open the "door".

My problem is that once the door is open the board is not detected. in the app. If - and only if - the door is closed the device shows up. With the door open I cannot select a board and clicking on the "Traces" icon shows no traces.

Somehow I need to be able to chose the VCP port for the incoming messages.

Using the terminal 

cat /dev/cu.usbxxx

I can see that with the door open the board sends out data.

Any hint on how to select the VCP port and to read USB PD communication in spy mode?

Thank you and best regards

Roland

[Nicolas P.]

Hello @RZitz​ 

Not sure to understand how you proceed. Having the door open, you cannot have the board listed in the board selection part. (For the details, when you are in spy mode, the GUI part is not started, therefore, the board will not answer to the UCPD monitor pings. ie Rx on the board is not enabled) But ... you can still have the protocol traces (Tx on board active as long as TRACER_EMB enabled).

With G0 disco in spy mode, you have to manually tell which COM port has to be used.

See the Wiki for more information.

[RZitz]

Hi and thank you for your answer.
Basically I simply want to trace / spy ongoing PD communication with two devices and the hardware in between and therefore I need to operate it with the blue door open for the second connector.
Since the GUI part is not started, how can I select the proper COM port to read the trace messages initially?
I tried to have the door closed first, select the port, open the door and connect the other cable and then read the trace messages.
However, this is rather unreliable since the STM32G0 board sometimes resets when opening the door i.e. operating that switch.
So my question is: How should I use the Spy mode to trace and get the messages out for viewing in the App?
I run the latest firmware:
~/STM32Cube/Repository/STM32Cube_FW_G0_V1.5.0/Projects/STM32G071B-DISCO/Demonstrations/USBPD_Analyzer
Thank you and best regards,
Roland

[Nicolas P. · Accepted solution]

It is described in the Wiki(link).

On the start screen, click on the button "TRACES" in the right bottom side.

It will open the trace panel.

Then click in the dark blue bar on the top right to "select Tracer Port" as in the below picture :

You should normally see in the drop down list your Linux serial port : /dev/ttyACM0 or similar.

Of course, you shouldn't move the door position while tracing, because the software running is completely different whether you have the door closed (sink mode) or open (spy mode)

Regards,

Nicolas