zephyr

History

Luca Burelli 187a8ad09b samples: fade_led: fix build error when PWM is not enabled Some boards may define LEDs but disable them by default due to conflicts with other peripherals. In this case, the new sample code introduced in `a5fd92b` ("samples: fade_led: use all available LEDs") fails to build with a missing symbol error. Fix this by checking if the PWM device (the parent of the LED alias) is enabled before using it. This implicitly discards invalid aliases. Signed-off-by: Luca Burelli <l.burelli@arduino.cc>		2025-02-06 14:47:15 +01:00
..
boards	samples: basic: add support for nRF54H20 cpuppr PWM	2025-01-31 09:38:25 +01:00
src	samples: fade_led: fix build error when PWM is not enabled	2025-02-06 14:47:15 +01:00
sysbuild/vpr_launcher	samples: basic: add support for nRF54H20 cpuppr PWM	2025-01-31 09:38:25 +01:00
CMakeLists.txt
prj.conf
README.rst	hwmv2: Introduce Hardware model version 2 and convert devices	2024-03-02 16:56:33 -05:00
sample.yaml	samples: basic: fade_led: add testing base on console output	2024-06-05 04:24:22 -07:00

README.rst

.. zephyr:code-sample:: fade-led
   :name: Fade LED
   :relevant-api: pwm_interface

   Fade an LED using the PWM API.

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
:zephyr:code-sample:`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.