gdsports

Post your code and any serial console debug output.

What SAMD board are you using? If you are using an Uno, Mega, or Leonardo with a USB host shield, look in the https://github.com/felis/USB_Host_Shield_2.0. I do not see how sketch...

The Zero is a good board for USB host debugging since it has two USB ports. I am glad to hear it is working.

I just verified the USB hub fixes from https://github.com/felis/USB_Host_Shield_2.0/pull/414 work on the USB Host Shield. I will see why they do not work on SAMD.

I think this commit fixes the problem. https://github.com/gdsports/USB_Host_Library_SAMD/commit/ac8c3233381280f68560b36ad7224b546fcec04d

> If so, what is the recovery process for when 'we' want to upgrade the f/w or purpose for something else? Double click the reset button puts the samd21 in...

In stock at digikey and mouser. digikey says it has over 8000 available to ship immediately.

The boot partition /boot is FAT32 so the overlay fs (read-only) does not apply. The overlay fs only applies to the Linux ext4 partition. This is the one that tends...

One problem occurred to me. Using overlayfs read-only means BT pairing will not be remembered across reboots/power cycles. I have no idea if the BT applet can save its config...

As I recall, the build worked for Pi4 but the file does not work. I had to checkout the older source code to make sure the Pi4 version of usb_f_hid.ko...