52 lines
1.9 KiB
ReStructuredText
52 lines
1.9 KiB
ReStructuredText
.. zephyr:code-sample:: lvgl-accelerometer-chart
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:name: LVGL line chart with accelerometer data
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:relevant-api: display_interface sensor_interface
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Display acceleration data on a real-time chart using LVGL.
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Overview
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********
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A sample application that demonstrates how to use LVGL and the :ref:`sensor` to
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display acceleration data on a line chart that is updated in real time.
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This sample creates a line chart with three series, one for each axis of the accelerometer. An LVGL
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timer fetches the latest acceleration data from the sensor every 20 ms (default value) and updates
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the chart. The update period is configurable, see
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:ref:`lvgl_accelerometer_chart_building_and_running` below.
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Requirements
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************
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* A board with a display.
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* A sensor that provides acceleration data (:c:enumerator:`SENSOR_CHAN_ACCEL_XYZ`) and available
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under the ``&accel0`` Devicetree alias.
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.. note::
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A Devicetree overlay declaring an emulated BMI160 accelerometer is provided for the
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``native_posix*`` and ``native_sim*`` board variants, making it possible to run this sample on
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your local machine.
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.. _lvgl_accelerometer_chart_building_and_running:
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Building and Running
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********************
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The maximum number of points to display for each series and the sampling rate of the
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accelerometer can be configured using the :kconfig:option:`CONFIG_SAMPLE_CHART_POINTS_PER_SERIES`
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and :kconfig:option:`CONFIG_SAMPLE_ACCEL_SAMPLING_RATE` Kconfig options, respectively.
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The default sampling rate is 50 Hz, and the default maximum number of points per series is 50.
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The demo can be built as follows (note how in this particular case the sampling rate is set to a
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custom value of 20 Hz):
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.. zephyr-app-commands::
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:zephyr-app: samples/modules/lvgl/accelerometer_chart
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:host-os: unix
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:board: native_sim
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:gen-args: -DCONFIG_SAMPLE_ACCEL_SAMPLING_RATE=20
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:goals: run
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:compact:
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