zephyr

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Anas Nashif 3ae52624ff license: cleanup: add SPDX Apache-2.0 license identifier Update the files which contain no license information with the 'Apache-2.0' SPDX license identifier. Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of Zephyr, which is Apache version 2. Signed-off-by: Anas Nashif <anas.nashif@intel.com>		2019-04-07 08:45:22 -04:00
..
src	…
CMakeLists.txt	license: cleanup: add SPDX Apache-2.0 license identifier	2019-04-07 08:45:22 -04:00
README.rst	…
prj.conf	…
sample.yaml	samples: add test identifier	2019-03-29 17:44:11 -04:00

README.rst

.. _blink-led-sample:

PWM: Blink LED
##############

Overview
********

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

The LED will start at a blinking frequency of 1 Hz. Every 4 seconds,
the blinking frequency will double. When the blinking frequency
reaches 64 Hz, the blinking frequency will be halved every 4 seconds
until the blinking frequency reaches 1 Hz. This completes a whole
blinking cycle. This faster-then-slower LED blinking cycle repeats forever.

Wiring
******

Nucleo_F401RE, Nucleo_L476RG, STM32F4_DISCOVERY, Nucleo_F302R8
==============================================================
Connect PWM2(PA0) to LED

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

Nucleo_L496ZG
=============
No special board setup is necessary because there are three on-board LEDs (red,
green, blue) connected to the Nucleo's PWM.

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

nrf52840_pca10056
=================
No special board setup is necessary because there is an on-board LED connected.

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.

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/blink_led
   :board: nrf52840_pca10056
   :goals: build flash
   :compact:

After flashing the image to the board, the user LED on the board should start to
blinking as discussed in overview