The K9 is similar to the PineTime and P8 devices but does not appear
to use the CST[78]16 touch screen controllers. At present the protocol
is not known (readfrom yields all zeros, readfrom_mem provokes an
exception) so we have a hugely limited interface consisting of the side
button and the touchscreen interrupts (in other words we can treat the
touchscreen like a second button).
Works suprisingly well considering...
Signed-off-by: Daniel Thompson <daniel@redfelineninja.org.uk>
2d1942f76a