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| author | Marti Bolivar <mbolivar@leaflabs.com> | 2011-05-27 23:56:38 -0400 |
|---|---|---|
| committer | Marti Bolivar <mbolivar@leaflabs.com> | 2011-05-28 00:09:44 -0400 |
| commit | c2d042ff66dad8e6d21b8101a5b4d30465a559d8 (patch) | |
| tree | fb683c921f1dbcd6d09b00b5e7b32ad454d69f6d /source/lang | |
| parent | c9993d6929e48b62097f08358c578983702f6185 (diff) | |
| download | librambutan-c2d042ff66dad8e6d21b8101a5b4d30465a559d8.tar.gz librambutan-c2d042ff66dad8e6d21b8101a5b4d30465a559d8.zip | |
Docs: Improve analogwrite.rst.
Make the note warning against its usage more direct. Add a blurb
introducing its purpose and links in See Also to related
board-specific values.
Diffstat (limited to 'source/lang')
| -rw-r--r-- | source/lang/api/analogwrite.rst | 25 |
1 files changed, 15 insertions, 10 deletions
diff --git a/source/lang/api/analogwrite.rst b/source/lang/api/analogwrite.rst index b553d8b..0169976 100644 --- a/source/lang/api/analogwrite.rst +++ b/source/lang/api/analogwrite.rst @@ -8,21 +8,23 @@ analogWrite() ============= +analogWrite() is used to create a :ref:`PWM <pwm>` wave on a pin. + .. note:: On the Maple, calling analogWrite() is the same as calling - :ref:`lang-pwmwrite`\ ; we recommend using that function directly - instead. + :ref:`lang-pwmwrite`. We recommend writing pwmWrite() instead of + analogWrite(). - This is because PWM is not true analog output (i.e., is not the - output of a `DAC + This is because PWM is not true analog output (it's not the output + of a `DAC <http://en.wikipedia.org/wiki/Digital-to-analog_converter>`_\ ), so - the function is badly named. For instance, analogWrite() **has - absolutely nothing to do with** :ref:`lang-analogread`\ , which is - potentially confusing. + the function is very badly named. For instance, **analogWrite() + has nothing to do with** :ref:`lang-analogread`\ , which can be + confusing. - The alias of analogWrite() to pwmWrite() is provided for the sake - of compatibility with Arduino only. + We provide analogWrite() for the sake of compatibility with Arduino + only. .. contents:: Contents :local: @@ -67,7 +69,7 @@ for more information. Another fix is to consult your board's :ref:`pin maps <gpio-pin-maps>` to find the timer which controls PWM on the pin you're using, then set -that Timer's overflow to 255. Subsequent calls to analogWrite() +that timer's overflow to 255. Subsequent calls to analogWrite() should work as on the Arduino (with the same loss of precision). Note, however, that that affects the overflow for the **entire timer**, so other code relying on that timer (such as any @@ -162,6 +164,9 @@ See Also -------- - :ref:`pwm` +- :ref:`lang-pwmwrite` +- :ref:`BOARD_NR_PWM_PINS <lang-board-values-nr-pwm-pins>` +- :ref:`boardPWMPins <lang-board-values-pwm-pins>` .. rubric:: Footnotes |