USB Device Library MaxPower after enumeration

Posted on July 27, 2016 at 11:50

Hi!

We're using ST USB Device Library. My question is about MaxPower field in device configuration descriptor.

Let's assume that we have value 0xFA which means that we want 500mA from USB port. That's fine since host shall give up to 500mA per USB port after enumeration is completed. Problem begins when we connect the device to passive USB hub, which shall give up to 100mA according to USB specification. So we need information about maximum power (current) assigned to our device by host after enumeration, to enter low-power mode (like running from battery instead of charging it). Is there any way to achieve this in ST USB Device Library?

#power #stm32f4 #usb #device