zephyr

History

Loic Poulain 16d8ce519c sample: blink_led: Adjust PWM period The maximum period a PWM controller can generate depends on its input clock and its resolution (16-bit, 32-bit...). Setting a 1s max period generates error with some hardwares (mimxrt1064_evk) because of clock limitation. This patch fixes this issue by calculating maximum period of the PWM device to adjust max and min periods accordingly. Signed-off-by: Loic Poulain <loic.poulain@linaro.org>		2019-08-07 07:38:40 -05:00
..
src	sample: blink_led: Adjust PWM period	2019-08-07 07:38:40 -05:00
CMakeLists.txt	license: cleanup: add SPDX Apache-2.0 license identifier	2019-04-07 08:45:22 -04:00
README.rst	samples: blink_led: remove whitelisting	2019-07-12 05:54:16 -07:00
prj.conf	driver: pwm: use new logger	2018-10-08 17:49:12 -04:00
sample.yaml	samples: blink_led: remove whitelisting	2019-07-12 05:54:16 -07:00

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.

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