apichanges.md: Add a section on the renames of constants for C ports

Signed-off-by: Jon Trulson <jtrulson@ics.com>
This commit is contained in:
Jon Trulson 2017-04-05 13:14:48 -06:00
parent e6ed49427a
commit 76a12af15f

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@ -6,10 +6,46 @@ compatibility between releases:
# current master
* **Note for all drivers ported to C** As a general note concerning
all of the drivers that have been ported to C: **external constants
have likely been renamed**. Previously in C++, most these constants
were defined as enums in the *upm::classname* namespace.
For drivers written in C, all of these constants are no longer in
a class (or UPM) namespace, and instead have the driver name
prefixed to the original value.
The driver name is prefixed to these constants to avoid name
collisions when using multiple drivers in a given application, and
to make it clear which constants belong to which driver.
For drivers that used *#define* for constants, only the prefix has
been added if not already present. In some cases, names that were
not very descriptive were changed, for example *ADDR* renamed to
*BMPX8X_DEFAULT_I2C_ADDR*.
So for example, a constant that might once have been referred to
in a C++ example as *upm::MMA7660::AUTOSLEEP_64*, would now be
referenced as *MMA7660_AUTOSLEEP_64*.
This holds true for most, if not all drivers that have been ported
to C. Not all of these changes are listed in this file due to the
sheer number of them.
If you run into problems with constants that were working
previously, and now cannot be found, this is likely the reason.
Check the driver documentation and the source code to see what the
new name is.
In C, constants are now usually implemented in a separate header
file named *drivername_defs.h* or *drivername_regs.h*, for easier
integration into the SWIG languages, and shared use between C++ and
C implementations.
* **bmpx8x** This driver has been rewritten from scratch in C, with a
C++ wrapper.
All exported symbols have been renamed for consistancy and to
All exported symbols have been renamed for consistency and to
avoid symbol collisions by having a *BMPX8X_* prefix. As an example,
*ADDR* has been renamed to *BMPX8X_DEFAULT_I2C_ADDR*. Most C
ported drivers follow this rule.
@ -51,8 +87,9 @@ compatibility between releases:
* **mma7660** This driver has been rewritten in C. Some exported
symbols have been changed, for example, *MMA7660_I2C_BUS* was renamed
to *MMA7660_DEFAULT_I2C_BUS*. See updated documentation and examples
for other changes.
to *MMA7660_DEFAULT_I2C_BUS*.
See updated documentation and examples for other changes.
* **bmx055, bmi055, bmc150, bma250e, bmg160, bmm150** This driver has
been split up. The *bma250e*, *bmg160*, *bmm150* drivers have been
@ -77,7 +114,7 @@ compatibility between releases:
library to do most of it's work. In addition, an additional argument
was added to the constructor to optionally allow specifying a GPIO
pin to be used to control the backlight. This driver supports the
SainsmartKS and DFRobot LCD Keypad Shields. Similiar devices from
SainsmartKS and DFRobot LCD Keypad Shields. Similar devices from
other manufacturers should also work with this driver.
* **lcm1602/jhd1313m1** These drivers had been rewritten in C, with
@ -97,7 +134,7 @@ compatibility between releases:
drivers. The *createChar()* function now accepts a byte vector
*std::vector<uint8_t>* rather than the *char ** pointer that was
used previously. This should make it easier to use with the SWIG
language bindings (Python, Javascript, and especially Java).
language bindings (Python, JavaScript, and especially Java).
* **bmp280/bme280** Some private methods are no longer exposed (such
as the calibration and compensation routines). In addition,
@ -109,8 +146,8 @@ compatibility between releases:
the appropriate type are used. In addition, methods that previously
returned certain data in the form of an array, like *getEulerAngles()*,
now return a *std::vector* instead. This simplifies the Python,
Javascript, and Java bindings considerably, and leads to more
"natural" looking Python/Javascript/Java code. For Javascript, Java,
JavaScript, and Java bindings considerably, and leads to more
"natural" looking Python/JavaScript/Java code. For JavaScript, Java,
and Python, the examples have been modified to use these methods
rather than the methods that return data in argument pointers or
arrays.