Having a choice with a defined set of options is nice, but it
also requires these options to be #defined somewhere _before_
entering config.h. To keep class-like encapsulation, we'd need
two header files for each code unit, one for the options, another
one for the usual header.
That said, we use other examples of such options, e.g. CPU, F_CPU
or KINEMATICS. For CPU and F_CPU it works fine, because their
options are numbers or other values known by the compiler. For
KINEMATICS it kind of works, because this #define is used in only
one place ... and there it's suboptimal already, because no option-
set.
Anyways, I was unsure about this change and if it turns out to be
a poor decision later, it can be reverted.
Most work by Ruslan Popov, collected from various commits and
made compatible with regression tests by Traumflug.
Display test code is now enabled by #defining DISPLAY_BUS to
i2c_twi.
Implemented and tested for both platforms. This is quite a big
commit. Unlike with the previous changes to now choosable PWM
frequencies, all board configuration files and Configtool had
to be changed immediately to deal with the additional parameter
in DEFINE_HEATER() and keep AVR builds working (and regression
tests passing).
Especially at high frequencies the achieved one is only close,
but that's entirely sufficient for our purposes.
Test: the PWM frequency on the scope should be similar to the
one configures in the board file with DEFINE_HEATER().
Currently at a fixed frequency of 1 kHz and with a fixed duty
cycle of 10%, but PWM does work.
As it turns out, PIO0_11 is not usable for PWM, because its timer
is already in use for the Step timer, and had to be disabled for
Gen7-ARM.
Test: define a heater in board.gen7-arm.h and a square signal
of 1 kHz with 10% duty cycle should appear on the heater pin.
Markus Hitter
Ruslan Popov
Witold Sowa