USB-PD over STM32G0 in default current mode

[Vvedr.11]

Hello,

I'm testing USB Power Delivery (in dula role power) over STM32G0.

I used ST wiki guide : https://wiki.st.com/stm32mcu/wiki/Introduction_to_USB_Power_Delivery_with_STM32

It's works except for a specific case :

• STM32G0 is configured in DRP-Source with PDO 5V/2A
• I connect to it a Sink which required 5V/3A
• Then the Source can provide this power
• In this case, I would like that USB power works at default current (500mA)
• Unfortunatly, it doesn't work and USB-PD power negociation restarts indefinitely

Is there a way to correct that ?

 

[FBL]

Hello @Vvedr.11 

Have you tried this wiki? STM32StepByStep:Getting started with USB-Power Delivery Sink - stm32mcu used with NUCLEO-G071RB 

[Vvedr.11]

No, Because I want a Dual Role Power device.

I used this one : https://wiki.st.com/stm32mcu/wiki/STM32StepByStep:Getting_started_with_USB-Power_Delivery_Dual_Role

 

[FBL]

 https://wiki.st.com/stm32mcu/wiki/Introduction_to_USB_Power_Delivery_with_STM32#Why_cannot_I_get_a_higher_voltage_contract-3F 

I hope this helps !

[Vvedr.11]

Unfortunately not.

My issue is to control current provide and not Voltage settings.

[FBL]

Hi again @Vvedr.11 

You need to use UCPD monitor hardware components to measure and control the current for further investigation. Controlling current involves voltage settings. You should check your PDOs in the file usbpd_pdo_defs.h, if you have activated the utility (_GUI_INTERFACE switch), in the STM32CubeMonitor-USBPD 'Port Configuration/SINK Capabilities' tab. It's possible that your operational current is too high for what your source can provide. You may need to adjust the PDOs to match the capabilities of your source and sink.

[Vvedr.11]

I checked with STM32CubeMonitor-USBPD and data confirmed that Sink asks more current than Source can provide.

In my application, I design only the Source and it's mandatory to limit it to 5V/2A. I can't adjust Sink capability because any USB-C device can be connect to it.

In the case where the Sink asks more current than Source can provide, I want limit current to legacy 500mA. but I don't know how to do that.

[FBL]

Hi again @Vvedr.11 

Unfortunately, the request may be rejected because the current request is too high compared to the source capabilities.

For further support, It would be helpful to have the protocol trace see here