2017-04-05 03:20:40 +08:00
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.. _blink-led-sample:
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2017-01-09 22:12:15 +08:00
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PWM: Blink LED
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##############
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Overview
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2017-01-21 07:58:05 +08:00
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********
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2017-01-09 22:12:15 +08:00
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2016-09-24 07:31:32 +08:00
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This is a sample app which blinks a LED using PWM.
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2017-07-25 01:49:59 +08:00
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The LED will start at a blinking frequency of 1 Hz. Every 4 seconds,
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2016-09-24 07:31:32 +08:00
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the blinking frequency will double. When the blinking frequency
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2017-07-25 01:49:59 +08:00
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reaches 64 Hz, the blinking frequency will be halved every 4 seconds
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until the blinking frequency reaches 1 Hz. This completes a whole
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blinking cycle. This faster-then-slower LED blinking cycle repeats forever.
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2016-09-24 07:31:32 +08:00
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2017-01-09 22:12:15 +08:00
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Wiring
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2017-01-21 07:58:05 +08:00
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******
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2017-01-09 22:12:15 +08:00
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2016-09-24 07:31:32 +08:00
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Arduino 101 and Quark D2000 CRB
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2017-01-21 07:58:05 +08:00
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===============================
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2016-09-24 07:31:32 +08:00
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You will need to connect the LED to ground and PWM0 via the shield.
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You may need a current limiting resistor. See your LED datasheet.
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2016-11-29 16:12:51 +08:00
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Nucleo_F401RE and Nucleo_L476RG
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2017-01-21 07:58:05 +08:00
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===============================
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2016-11-29 16:12:51 +08:00
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Connect PWM2(PA0) to LED
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Nucleo_F103RB
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2017-01-21 07:58:05 +08:00
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=============
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2016-11-29 16:12:51 +08:00
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Connect PWM1(PA8) to LED
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2017-01-09 22:12:15 +08:00
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2017-07-25 01:49:59 +08:00
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Hexiwear K64
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============
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No special board setup is necessary because there is an on-board RGB LED
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connected to the K64 PWM.
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2017-01-09 22:12:15 +08:00
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Building and Running
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2017-01-21 07:58:05 +08:00
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********************
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2017-01-09 22:12:15 +08:00
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This sample can be built for multiple boards, in this example we will build it
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for the arduino_101 board:
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.. code-block:: console
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$ cd samples/basic/blink_led
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$ make BOARD=arduino_101
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$ make BOARD=arduino_101 flash
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After flashing the image to the board, the user LED on the board should start to
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blinking as discussed in overview
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