STM32G071 USB sink

[PNada.1]

I am currently using the Nucleo G071 RB eval board. The application will transfer data to the USB port at the end of processing. I am using UCPD1 on PA10, PA9, PA8 and PB15.

Do I use the STM32CubeMonitorUCPD to view this data? I am assuming I will need to jumper these UCPD1 pins to a USB cable that connects to my laptop.

Is RTOS needed to use UCPD1 for this purpose?

Thanks,

Priya

[Nicolas P.]

Hello Priya,

I'm a bit confused by your question.

First the Nucleo G071 is a different board than the eval board.

Then on G071, there is no USB available, but UCPD that stands for USB power delivery.

USB feature will be available in the coming update of STM32G0 : STM32G0C1E-EV (Eval board) or NUCLEO-G0B1RE in two weeks. (week 44)

You can also look at the STM32G4 or STM32L5 that suppport both USB and USBPD.

Do you wish to use USB (DP/DM) or power delivery protocol (with CC1/CC2 lines) ?

For your information, if you get a NUCLEO-G0B1RE, you will have the possibility to plug a shield will will bring the type C connectivity on top of the Nucleo-64 : X-NUCLEO-USBPDM1 shield.

With this shield you will also get the TCPP01 that will protect your STM32 from ESD, over voltage... see TCPP01.

For more information on power delivery, see the Wiki.

Regards,

Nicolas

[PNada.1]

Nicolas,

Thank you for your helpful reply. In one application the USB simply needs to transfer data to external processor. The external processor provides USB power.

The time constraints of this application may not need RTOS. Can you confirm if this is possible?

In the second application, the USB is largely used the same way as the first one (receives power one way), but it needs to be a dual role USB to provide power to some peripherals. It seems like RTOS will be needed for this. Can you confirm?

In the STM32 cube MX generator, the peripherals available were UCPD1 and UCPD2. When the STM32G071 Nucleo 64 board does not have USB ports, the pins seem to be available on the morpho connector. I was looking into the possibility of using a custom cable to plug into my laptop. Is this possible?

Please advice on the board and part for this application. They both need to have the same micro.

Thank you,

Priya

[Nicolas P. · Accepted solution]

For the first application, you can use the coming G0 512K or the G4 or L5. All these have USB available. Only G0 512K support USB host and device modes. (G4 and L5 are only USB device)

Even if you can connect USB DP/DM on the morpho, you need the integrated peripheral inside the MCU to run the USB stack. So no way, even with a custom cable on the STM32G071.

To get the VBUS, the UCPD needs to present the Rd resistor on the CC lines. Next CubeMx version, will provide (week 46) the possibility to have a "no PD" library, just to configure the correct CC line pull up/ pull down in the UCPD.

For your second application, you will need the USB power delivery protocol to support data role swap, and power role swap.

For the moment, we need RTOS to run the USB and the USB stack in parallel.