Only "DEFAULT 5V" contract is accessible in STM Cubemonitor UCPD !!

[DRoy.3]

I am currently building a USB PD programmable power supply sink application (upto 100 W) using Nucleo STM32G0 and X-Nucleo-SNK1M1 boards. While using the STM Cubemonitor UCPD interface, I am always getting a "DEFAULT 5V" contract (attached screenshot) and none of the other PDO options are accesible. How do I access the other PDO contracts, especially the PPS APDO?

[Nicolas P.]

Hello @DRoy.3​ 

On your picture we see that the VBUS is seen as default 5V.

It means that the source capabilities were not seen by your sink. What is the source connected to your device ?

Can you plug the source, only when UCPD monitor has been started, to be sure to get all the protocol messages from the start ?

Could you share the .cpd file ?

Regards,

Nicolas

[DRoy.3]

Hello Mr. Nicholas,

Thank you for the explanation. The issue was resolved, it was hardware related - I was using a USB PD sniffer (with a female input and male output) in series with the PD line. Due to this, the CC lines were getting disconnected (broken lines) in a particular orientation, which was then rectified by changing the orientation of the sniffer/cable. This is always a risk while using multiple USB type-C devices/ports in series.