zephyr

History

Sebastian Bøe 55ee53ce91 cmake: Prepend 'cmake_minimum_required()' into 'app' build scripts Prepend the text 'cmake_minimum_required(VERSION 3.8.2)' into the application and test build scripts. Modern versions of CMake will spam users with a deprecation warning when the toplevel CMakeLists.txt does not specify a CMake version. This is documented in bug #8355. To resolve this we include a cmake_minimum_required() line into the toplevel build scripts. Additionally, cmake_minimum_required is invoked from within boilerplate.cmake. The highest version will be enforced. This patch allows us to afterwards change CMake policy CMP000 from OLD to NEW which in turn finally rids us of the verbose warning. The extra boilerplate is considered more acceptable than the verbosity of the CMP0000 policy. Signed-off-by: Sebastian Bøe <sebastian.boe@nordicsemi.no>		2018-08-15 04:06:50 -07:00
..
src	arch: arm: nrf: Rename nrf5 SoC Family to nrf	2018-03-20 11:57:14 +01:00
CMakeLists.txt	cmake: Prepend 'cmake_minimum_required()' into 'app' build scripts	2018-08-15 04:06:50 -07:00
README.rst	samples: basic: Convert doc to CMake	2017-11-12 21:13:23 -05:00
prj.conf	samples: fade_led: Add support for hexiwear_k64	2017-08-09 18:13:29 -04:00
sample.yaml	samples: pwm: depend on boards supporting PWM	2017-12-28 20:24:29 -05:00

README.rst

.. _fade-led-sample:

PWM: Fade LED
#############

Overview
********

This is a sample app which fades a LED using PWM.

The LED will start from dark and increases its
brightness gradually for 10 seconds. Then, the
brightness reduces gradually for 10 seconds and
finally the LED becomes dark again. The LED will
repeat this cycle for ever.

Wiring
******

Arduino 101 and Quark D2000 CRB
===============================
You will need to connect the LED to ground and PWM0 via
the shield. You may need a current limiting resistor. See
your LED datasheet.

Nucleo_F401RE and Nucleo_L476RG
===============================
Connect PWM2(PA0) to LED

Nucleo_F103RB
=============
Connect PWM1(PA8) to LED

Hexiwear K64
============
No special board setup is necessary because there is an on-board RGB LED
connected to the K64 PWM.

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

This sample can be built for multiple boards, in this example we will build it
for the arduino_101 board:

.. zephyr-app-commands::
   :zephyr-app: samples/basic/fade_led
   :board: arduino_101
   :goals: build flash
   :compact: