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Rob.Riggs
Rob.Riggs
Senior
March 6, 2017
Question

Set USB Max Power for CDC Device Using STM32CubeMX?

  • March 6, 2017
  • 3 replies
  • 1146 views
Posted on March 06, 2017 at 01:23

I am using an STM32L4 device.  I am making a USB device that uses CDC and have battery charge detection enabled.  I need to request 500mA from the USB port if a standard downstream port is detected.  It appears that the max power is hard-coded for 100mA in 'Middlewares/ST/STM32_USB_Device_Library/Class/CDC/Src/usbd_cdc.c' and that this will be overwritten by STM32CubeMX every time the project is regenerated if I modify this file.

Is there an expected way that this value should be changed for CubeMX projects?  There does not appear to be any public interface into this device structure.

#stm32l4 #hal #usb #usb-power #cdc #stm32cubemx
This topic has been closed for replies.

3 replies

Nesrine M_O
Nesrine M_O
Associate
March 7, 2017
Posted on March 07, 2017 at 14:22

Hi

Riggs.Rob

,

Thank you for your feedback.I will forward this to our MX team.

-Nesrine-

stm32cube-t
stm32cube-t
ST Employee
March 9, 2017
Posted on March 09, 2017 at 16:02

Hello Rob,

As you noticed the USB descriptors are currently hard coded in the usbd_cdc.c file. We need an update of the USB middleware library to have these descriptors configurable via STM32CubeMX.

ali teke
ali teke
Visitor II
July 21, 2017
Posted on July 21, 2017 at 19:24

Hi @riggs.rob, you can access the structures and set it in run time. You may place your code inside usbd_conf.c file, maybe this helps to you.

void HAL_PCD_MspInit(PCD_HandleTypeDef* pcdHandle)

{

  if(pcdHandle->Instance==USB)

  {

  /* USER CODE BEGIN USB_MspInit 0 */

    uint16_t length;

    *(USBD_CDC.GetFSConfigDescriptor(&length) + 8) = (500 / 2);

  /* USER CODE END USB_MspInit 0 */

.

.

.

}

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