I have a device which does not support a USB hub, and does not supply power. I need to connect my phone to this device, and unfortunately this means I cannot also charge the phone while using it.
I tried the simple, naive approaches of:
- Trying a self-powered hub; the host device does not support a hub.
- Trying to supply power directly by severing the power lead from the device to the phone; the USB-based power negotiation tells the phone no power is available, and it won't charge.
- Shorting the data pins initially to cause the phone to charge, and then opening them up. As expected, this means it will not talk to the host device.
My thought is I need something that acts almost like a hub, but passes through all USB protocol messages other than those used for power negotiation, and will terminate those to cause power to be supplied.
Is there such a device?