I have a device based around an Overo Air COM and Tobi board that I would like to use a 4-port USB hub with to connect 4 peripherals (a wifi card, a webcam, a 3G dongle and a USB GPS device). There are a number of unpowered USB hubs that fit my requirements perfectly in terms of form factor, but they are very unstable during operation. I assume this is because at times with so many devices connected I’m trying to draw over 500mA at the same time and therefore not adhering to the spec.
A powered hub would provide the solution but they are typically much bigger and would end up probably doubling the size of my device.
Is there anything else other than the powered hub option that I could try to help me support all these devices in a mobile scenario? Would it be an option to directly supply power to the 5v line of the unpowered USB hub (rather than taking it from the host port)? Or is that likely to break my peripherals?
Thanks in advance for any help you can offer,