USB Access

In the default configuration, as shipped, USB in is peripheral mode and a “wall wart” AC adaptor can be used for power. In this mode, it is also possible to connect the development board to a workstation’s USB 3.0+ port (where VBUS can supply up to 900mA) and access a serial console, as described in Test Run.

Alternate Configuration - USB C Host

In this configuration, USB host mode is used to allow keyboard, mouse and flash memory sticks to be connected to the development board.

Note: Using the board in this mode means that you will lose access to the USB serial console, so it is important to have set up SSH access via Ethernet before following these steps.

  1. On the target, backup the device tree and copy in the USB host version:

    cp /boot/dtbs/librem5-evk.dtb /boot/dtbs/librem5-evk.dtb.bak
    cp /boot/dtbs/librem5-evk-usbhost.dtb /boot/dtbs/librem5-evk.dtb
  2. Attach a USB C hub to the development board.

  3. Attach power to the USB C hub.

  4. Plug in USB devices and they should appear in the output of the dmesg and lsusb tools.

The J5 Create JCA374 USB Type-C Multi-Adapter is known to work as a hub and power the board using USB Power Delivery.