if transition_mode pin is high, then images are shown continuosly
(eg the next image is shown as soon as the next_image button is pressed)
but if transition_mode pin is low, then, when you press the button, the
current image disappears, and the next one appears when you press the
button again
This does not work as expected, and I don't understand why.
Clock cycle count seems ok, but if there are no changes in the pixels,
it seems to go faster
This makes the microcontroller very application dependent,
but may save use some headaches.
The idea is to write a program to produce the code to show a
complex drawing.
sufficiently handles the back/front porch without disrupting the sync
signal
todo improvement: compute a sensible amount of cycles to waste during
the porch
not the whole screen, but vertically locked
actually it has some issues, there is a single dot (at the
end/beginning of a cycle) that messes up the horizontal sync and moves
all the picture... must be fixed