especially if it merges an updated upstream into a topic branch.

This does not compile yet, to be fixed.

This will allow us to use power-down sleep when neither ADC nor PWM
is used.

Simplify it as much as possible - single PWM channel only, no
sub-LSB PWM value.

from http://www.fi.muni.cz/~kas/bike-lights/ Git repository as of
commit c30006aaf666f7cff3a6ab949c613c2f8cc6163b

So far two PWM channels OC1A/OC1B with sub-LSB resolution possible
(but unused yet) using timer IRQ.

TODO: get rid of OCR1C register and let it count to 255.

These are firmware source code files imported verbatim from
the Project Bike Lights, as of commit
c30006aaf666f7cff3a6ab949c613c2f8cc6163b:

http://www.fi.muni.cz/~kas/git/?p=bike-lights.git;a=tree;f=firmware;hb=c30006aaf666f7cff3a6ab949c613c2f8cc6163b

These will not run directly on Tinyboard - I just want to have
documented all the changes I plan to make against these source code
files (and possibly to merge some future patches into both projects).

I have decided to add various projects using Tinyboard directly
to this repository. The first project is a step-up converter
with current feedback for a string of LEDs.

The firmware is a dumbed-down version of firmware for my other
project: http://www.fi.muni.cz/~kas/bike-lights/, modified
for ATtiny45.