zephyr

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Gerard Marull-Paretas ae91933c4a drivers: pwm: always use nanoseconds for set In order to be consistent with what is possible in Devicetree, always take a period in nanoseconds. Other scales or units may be specified by using, e.g., the PWM_MSEC() macros (all of them converting down to nanoseconds). This change then deletes the "_nsec" and "_usec" versions of the pwm_set call. Note that this change limits the period to UINT32_MAX nanoseconds, ~4.3s. PWM is, in generali, used with periods below the second so it should not be a problem. Signed-off-by: Gerard Marull-Paretas <gerard.marull@nordicsemi.no>		2022-04-28 11:29:38 +02:00
..
src	drivers: pwm: always use nanoseconds for set	2022-04-28 11:29:38 +02:00
CMakeLists.txt	…
README.rst	samples: basic: fade_led: use pwm_dt_spec	2022-04-28 11:29:38 +02:00
prj.conf	…
sample.yaml	…

README.rst

.. _fade-led-sample:

Fade LED
########

Overview
********

This application "fades" a LED using the :ref:`PWM API <pwm_api>`.

The LED starts off increases its brightness until it is fully or nearly fully
on. The brightness then decreases until the LED is off, completing on fade
cycle. Each cycle takes 2.5 seconds, and the cycles repeat forever. The PWM
period is taken from Devicetree. It should be fast enough to be above the
flicker fusion threshold.

Requirements and Wiring
***********************

This sample has the same requirements and wiring considerations as the
:ref:`pwm-blinky-sample`.

Building and Running
********************

To build and flash this sample for the :ref:`nrf52840dk_nrf52840`:

.. zephyr-app-commands::
   :zephyr-app: samples/basic/fade_led
   :board: nrf52840dk_nrf52840
   :goals: build flash
   :compact:

Change ``nrf52840dk_nrf52840`` appropriately for other supported boards.

After flashing, the sample starts fading the LED as described above. It also
prints information to the board's console.