Bring USB device to life

[aethaniel]

The existing SAM USB device stack has been proven to be slow, specially versus Teensy 3.x.
This function needs time to be spent.

[logos-electromechanical]

Where is this part of the project? I'm not really familiar with USB from the stack perspective, so I'm not sure how to contribute to this issue. :(

[aethaniel]

this will come in time: we need to check the existing Arduino USB device stack and make it more efficient, if possible, or rewrite the foundations: the famous chapter 9 and right after device classes drivers

[logos-electromechanical]

Not having it is somewhat painful for me. Would you object to me standing it up as it is and refactoring it for speed later?

[aethaniel]

Yes, I object doing something quick and dirty :-|

But, to let you move without pain, I just pushed as-is the USB device stacking coming from Flutter Wireless port (https://github.com/flutterwireless/ArduinoCodebase). This port isn't really what I would like to see here but at least it is working on SAM3S1 and should be 'easy' to use on SAM4S.

Play with it, fix some wrong #include, don't forget to add all .c and .cpp files in your variant makefile and you should be ok for a while.

Branch is here: https://github.com/aethaniel/ExperimentalCore-sam/tree/usb_device_from_flutter_wireless