TS-7970 HD1 Header
HD1 is a 2x12 0.10" pitch header including DIO, USB, SPI, an IRQ, 3.3V, and 5V. All GPIO are 3.3V tolerant unless otherwise specified.
The USB port on this header is normally the top USB port near the Ethernet connectors. This can instead by routed to this header by changing the mux:
# Select HD1 USB echo 1 > /sys/class/leds/sel_dc_usb/brightness # Select external type A USB port echo 0 > /sys/class/leds/sel_dc_usb/brightness