55 lines
1.7 KiB
ReStructuredText
55 lines
1.7 KiB
ReStructuredText
.. zephyr:code-sample:: multi-thread-blinky
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:name: Basic thread manipulation
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:relevant-api: gpio_interface thread_apis
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Spawn multiple threads that blink LEDs and print information to the console.
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Overview
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********
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This example demonstrates spawning multiple threads using
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:c:func:`K_THREAD_DEFINE`. It spawns three threads. Each thread is then defined
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at compile time using K_THREAD_DEFINE.
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The first two each control an LED. These LEDs, ``led0`` and ``led1``, have
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loop control and timing logic controlled by separate functions.
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- ``blink0()`` controls ``led0`` and has a 100ms sleep cycle
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- ``blink1()`` controls ``led1`` and has a 1000ms sleep cycle
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When either of these threads toggles its LED, it also pushes information into a
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:ref:`FIFO <fifos_v2>` identifying the thread/LED and how many times it has
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been toggled.
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The third thread uses :c:func:`printk` to print the information added to the
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FIFO to the device console.
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Requirements
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************
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The board must have two LEDs connected via GPIO pins. These are called "User
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LEDs" on many of Zephyr's :ref:`boards`. The LEDs must be configured using the
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``led0`` and ``led1`` :ref:`devicetree <dt-guide>` aliases, usually in the
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:ref:`BOARD.dts file <devicetree-in-out-files>`.
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You will see one of these errors if you try to build this sample for an
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unsupported board:
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.. code-block:: none
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Unsupported board: led0 devicetree alias is not defined
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Unsupported board: led1 devicetree alias is not defined
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Building
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********
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For example, to build this sample for :ref:`96b_carbon_board`:
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.. zephyr-app-commands::
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:zephyr-app: samples/basic/threads
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:board: 96b_carbon/stm32f401xe
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:goals: build flash
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:compact:
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Change ``96b_carbon/stm32f401xe`` appropriately for other supported boards.
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