This USB feature is currently not supported. With this flag enabled (and
the feature not implemented) the USB serial will stop working if there is a
delay of more than about 2 seconds between messages, which can occur with
USB autosuspend enabled.
Fixes issue #6866.
This commit adds a new port "rp2" which targets the new Raspberry Pi RP2040
microcontroller.
The build system uses pure cmake (with a small Makefile wrapper for
convenience). The USB driver is TinyUSB, and there is a machine module
with most of the standard classes implemented. Some examples are provided
in the examples/rp2/ directory.
Work done in collaboration with Graham Sanderson.
Signed-off-by: Damien George <damien@micropython.org>
