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Controlling the Power for USB Ports
Since revision 2, BIG7 USB hub has a new footprint for 2-pin
header (P7) on the top-right corner of the board. This header is
not populated and it is reserved for users who wants to control the
power for USB port with software or external switch.
The ENABLE pin is pulled up (to 3.3V) by default. The power of USB ports will be cut
when the ENABLE pin is shorted to the GND (ground) pin. By cutting the power of
USB peripherals, they can not draw any current from the USB hub and doing so can
save the power consumption. This would be very useful if your project is running with
very limited power source (battery, solar panel etc.).
If you connect an external switch to these two pins, you can use that switch to turn
on/off the power for all USB ports.
You can also connect the ENABLE pin to a GPIO pin in Raspberry Pi, and control the
USB ports’ power by setting the GPIO pin high/low.
Below is an example of controlling the power with GPIO-23 (BCM naming) pin on
Raspberry Pi 3:
