Hi supporter,I have one question: I want to change Port Role when no cable connect, can I do it?my behavior:Init usbpd with default role is Sinkwhen my application running, I see my adapter plugin, I want change my port to sinkCan I do that?

Associate III

Question

USB-PD default role initialize & change

Hi supporter,

I have one question: I want to change Port Role when no cable connect, can I do it?

my behavior:

Init usbpd with default role is Sink
when my application running, I see my adapter plugin, I want change my port to sink

Can I do that?

ST Employee

Hello @H V N D ,

I'm not sure to fully understand.

If you have DRP, and nothing is connected, your port Role has to toggle.

You have a DRP, and in case you are connected as a source, you want to switch to sink role ?

In this case you have to request a power role swap.

Sequence is indicated on our wiki.

Is that what you are looking for ?

Nicolas

Associate III

My problem is:

when I power my STM32, I don't know the power supply to STM32 is from Adapter or Vbus of Phone ( because ADC init and convert slow, when app task run I can know )
If I want my Port is source, I must wait cable connect and change to source by PowerRoleSwap ( because default is Sink )

Can I change my port is source even no cable connect?

ST Employee

You can change role when you are not yet attached; that's the purpose of role toggling when you are DRP (dual role power) capable.

And when you are attached, you can request a role change by sending a message, like mentioned in previous message on the wiki.

Using the UCPD in our microcontrollers, the role toggling has to be done by the application : it is not automatically done by hardware.