The three classes I2C, SPI and USART now have a fairly uniform (Python)
API. All are constructed, initialised and deinitialised in the same
way. They can have most of their parameters set, using keyword arguments.
All have send and recv (although slightly different with I2C requiring an
address in master mode). recv can do inplace receiving (ie store the
data in a previously-created bytearray).
It's just polling mode at the moment, but interrupt and DMA would be
nice to add.
This is an attempt to clean up the Micro Python API on the pyboard.
Gpio functionality is now in the Pin object, which seems more natural.
Constants for MODE and PULL are now in pyb.Pin. Names of some
classes have been adjusted to conform to CamelCase. Other
miscellaneous changes and clean up here and there.
Pretty much everyone needs to include map.h, since it's such an integral
part of the Micro Python object implementation. Thus, the definitions
are now in obj.h instead. map.h is removed.
All board config macros now begin with MICROPY_HW_.
Renamed PYBv10 to PYBV10, since macros should be all uppercase.
Made SDCARD_DETECT configurable in mpconfigport.h, so that the SD
detect pin can be easily configured.
Originally, .methods was used for methods in a ROM class, and
locals_dict for methods in a user-created class. That distinction is
unnecessary, and we can use locals_dict for ROM classes now that we have
ROMable maps.
This removes an entry in the bloated mp_obj_type_t struct, saving a word
for each ROM object and each RAM object. ROM objects that have a
methods table (now a locals_dict) need an extra word in total (removed
the methods pointer (1 word), no longer need the sentinel (2 words), but
now need an mp_obj_dict_t wrapper (4 words)). But RAM objects save a
word because they never used the methods entry.
Overall the ROM usage is down by a few hundred bytes, and RAM usage is
down 1 word per user-defined type/class.
There is less code (no need to check 2 tables), and now consistent with
the way ROM modules have their tables initialised.
Efficiency is very close to equivaluent.
