zephyr

History

Anas Nashif efb47ace39 doc: samples: cleanup board reference and layout Cleanup references to boards in some of the example and use the same boards through the examples. Other minot cleanups and make the text more generic and not specific to certain boards. Signed-off-by: Anas Nashif <anas.nashif@intel.com>		2019-06-13 16:09:02 -04:00
..
src	all: Add 'U' suffix when using unsigned variables	2019-03-28 17:15:58 -05:00
CMakeLists.txt	license: cleanup: add SPDX Apache-2.0 license identifier	2019-04-07 08:45:22 -04:00
prj.conf	driver: pwm: use new logger	2018-10-08 17:49:12 -04:00
README.rst	doc: samples: cleanup board reference and layout	2019-06-13 16:09:02 -04:00
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 nrf52840_pca10056 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