This aligns the I2C class to match the standard machine.I2C API.
Note that this is a (small) breaking change to the existing cc3200 API.
The original API just returned the size of the input buffer so there's no
information lost by this change. To update scripts users should just use
the size of the buffer passed to these functions to get the number of bytes
that are read/written.
This is a user-facing change to the cc3200's API, to make it conform to the
new machine hardware API. The changes are:
- change I2C constructor to: I2C(id=0, *, freq=100000, scl=None, sda=None)
- change I2C init to: init(*, freq, scl, sda)
- removal of machine.I2C.MASTER constant
- I2C str/repr no longer prints I2C.MASTER
To update existing code it should be enough to just remove the I2C.MASTER
constant from contructor/init for I2C.
A standard I2C address is 7 bits but addresses 0b0000xxx and 0b1111xxx
are reserved. The scan() method is changed to reflect this, along with
the docs.
The first argument to the type.make_new method is naturally a uPy type,
and all uses of this argument cast it directly to a pointer to a type
structure. So it makes sense to just have it a pointer to a type from
the very beginning (and a const pointer at that). This patch makes
such a change, and removes all unnecessary casting to/from mp_obj_t.
py/mphal.h contains declarations for generic mp_hal_XXX functions, such
as stdio and delay/ticks, which ports should provide definitions for. A
port will also provide mphalport.h with further HAL declarations.
In general the changes are:
1. Peripheral (UART, SPI, ADC, I2C, Timer) IDs start from 1, not zero.
2. Make I2C and SPI require the ID even when there's only one bus.
3. Make I2C and SPI accept 'mode' parameter even though only MASTER
is supported.
Previous to this patch the printing mechanism was a bit of a tangled
mess. This patch attempts to consolidate printing into one interface.
All (non-debug) printing now uses the mp_print* family of functions,
mainly mp_printf. All these functions take an mp_print_t structure as
their first argument, and this structure defines the printing backend
through the "print_strn" function of said structure.
Printing from the uPy core can reach the platform-defined print code via
two paths: either through mp_sys_stdout_obj (defined pert port) in
conjunction with mp_stream_write; or through the mp_plat_print structure
which uses the MP_PLAT_PRINT_STRN macro to define how string are printed
on the platform. The former is only used when MICROPY_PY_IO is defined.
With this new scheme printing is generally more efficient (less layers
to go through, less arguments to pass), and, given an mp_print_t*
structure, one can call mp_print_str for efficiency instead of
mp_printf("%s", ...). Code size is also reduced by around 200 bytes on
Thumb2 archs.
I2C objects can be freed by the GC and a __del__ method is provided
in order to de-init the peripheral prior to being garbage collected.
UART objects are now added to a local list and this list is now part
of the VM_STATE.
Alexander Steffen