USB PD change voltage during active contract

[abtq]

Dear ST Community,

 

I have a working application for USB PD SPR and EPR and now I want to change the voltage (power profile) during an active contract.
So e.g. I have 5V currently and want to request 9V from the source, or I have 20V currently and want to switch to 28V (EPR).
How to do that? According to the USB Specification you would send a "Get Source Capability" Request so I used USBPD_DPM_RequestGetSourceCapability() [or USBPD_PE_Send_ExtendeControlMessage(m_uPort, USBPD_EXTENDED_CONTROL_EPR_GETSRCCAPA) in EPR]. Then the source responds with it's capabilities. USBPD_DPM_SetDataInfo gets called with the PDOs but USBPD_DPM_SNK_EvaluateCapabilities is never called afterwards....
In SPR Mode nothing happens, voltage stays the same. In EPR Mode 30ms later a hard reset is triggered.

 

Why does the ST Stack not Evaluate Capabilities after successfull reception of PDOs? According to USB Spec as a Sink we always need to respond to a capabilities message with our "wish".....

 

How to fix that?

I am using Core Stack version V5.3.0 (latest version as of writing this post). Microcontroller used is STM32H523.

 

Regards,

Adrian

[FBL]

Hi @abtq 

Would you share minimum firmware to reproduce the issue on a reference board? 

[abtq]

Hi @FBL ,

I now have added a workaround: In USBPD_DPM_SetDataInfo() for USBPD_CORE_DATATYPE_RCV_SRC_PDO and USBPD_CORE_DATATYPE_RCV_SRC_PDO_EPR I added

if(usb.m_bChangingProfile && DPM_Params[PortNum].PowerRange == USBPD_EPR_MODE) {
 evaluateAndRequest(); // if an contract is active we need to evaluate our selves
}

(or check for SPR mode in similar fashion).

With:

bool CUSBPowerDelivery::evaluateAndRequest() {
	USBPD_SNKRDO_TypeDef uRequestData;
	USBPD_CORE_PDO_Type_TypeDef type;
	USBPD_DPM_SNK_EvaluateCapabilities(m_uPort, &uRequestData.d32, &type);
	USBPD_StatusTypeDef status = USBPD_PE_Send_Request(m_uPort, uRequestData.d32, type);
	if(status != USBPD_OK) {
 return false;
	}
	return true;
}

 

But in fact the ST stack should do that on its own? If so I will have to look into that and compose a minimal example to see whether this is a problem in my environment or whether the behaviour is the same in the minimal example.

 

[FBL]

Hi @abtq 

That would be great to share minimal project to reproduce on ! An internal ticket 215626 is submitted to USB PD stack team to answer all related questions!

Thank you

[abtq]

---

@FBL wrote:

Hi @abtq 

That would be great to share minimal project to reproduce on ! An internal ticket 215626 is submitted to USB PD stack team to answer all related questions!

Thank you

---

Is there any update on this topic? Can you reproduce this issue using the minimal sample?

I guess I don't have access to the internal ticket?

[FBL]

Hi @abtq 

Currently, ST’s USB PD stack does not provide application examples or full support for EPR mode. Do you have any issues running the SPR mode?