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211 lines
7.8 KiB
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211 lines
7.8 KiB
ReStructuredText
MAX7219 Digit Display
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=====================
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.. seo::
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:description: Instructions for setting up MAX7219 Digit displays.
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:image: max7219digit.png
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The ``max7219`` display platform allows you to use MAX7219 digit with ESPHome. Please note that this integration
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is *only* for the digit "matrix" display, for the 7 segment display see :doc:`max7219`.
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.. figure:: images/max7219digit.png
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:align: center
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:width: 75.0%
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MAX7219 Digit Display.
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As the communication with the MAX7219 Digit is done using SPI for this integration, you need
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to have an :ref:`SPI bus <spi>` in your configuration with both the **mosi_pin** set (miso_pin is not required).
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Connect VCC to 3.3V (the manufacturer recommends 4+ V, but 3.3V seems to work fine), DIN to your ``mosi_pin`` and
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CS to your set ``cs_pin`` and finally GND to GND.
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You can even daisy-chain multiple MAX7219s by connecting the DOUT of the previous chip in the chain to the
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next DIN. With more than ~3 chips the 3.3V will probably not be enough, so then you will have to potentially
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use a logic level converted.
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.. code-block:: yaml
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# Example configuration entry
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spi:
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clk_pin: D0
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mosi_pin: D1
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display:
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- platform: max7219digit
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cs_pin: D2
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num_chips: 4
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intensity: 15
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lambda: |-
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it.print(0, 0, id(digit_font), "HELLO!");
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Configuration variables:
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------------------------
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- **cs_pin** (**Required**, :ref:`Pin Schema <config-pin_schema>`): The pin you have the CS line hooked up to.
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- **num_chips** (*Optional*, integer): The number of chips you wish to use for daisy chaining. Defaults to
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``4``.
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- **rotate_chip** (*Optional*): Rotates every 8x8 chip. Valid values are ``0``, ``90``, ``180`` and ``270``.
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Defaults to ``0``.
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- **scroll_enable** (*Optional*, boolean): Turn scroll mode on when content does not fit. Defaults to ``true``.
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- **scroll_mode** (*Optional*): Set the scroll mode. One of ``CONTINUOUS`` or ``STOP``. Defaults to ``CONTINUOUS``
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- ``CONTINUOUS``: Always scrolls and the text repeats continuously, you might need to add some
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separation at the end.
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- ``STOP``: When text is over it waits the ``scroll_dwell`` time and scroll is set back to the start.
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- **scroll_speed** (*Optional*, :ref:`config-time`): Set scroll speed. Defaults to ``250ms``
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- **scroll_delay** (*Optional*, :ref:`config-time`): Set delay time before scroll starts. Defaults to ``1s``.
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- **scroll_dwell** (*Optional*, :ref:`config-time`): Sets the wait time at the end of the scroll before starting
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over. This is only used in mode ``STOP``. Defaults to ``1s``.
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- **reverse_enable** (*Optional*, boolean): For some displays the order of the displays is reversed ("DCBA"). This option will reverse the display to ("ABCD") again. Defaults to ``false``.
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- **intensity** (*Optional*, integer): The intensity with which the MAX7219 should drive the outputs. Range is
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from ``0``, least intense to ``15`` the brightest. Defaults to ``15``.
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- **lambda** (*Optional*, :ref:`lambda <config-lambda>`): The lambda to use for rendering the content on the
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MAX7219. See :ref:`display-max7219digit_lambda` for more information.
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- **update_interval** (*Optional*, :ref:`config-time`): The interval to re-draw the screen. Defaults to ``1s``.
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- **spi_id** (*Optional*, :ref:`config-id`): Manually specify the ID of the :ref:`SPI Component <spi>` if you want
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to use multiple SPI buses.
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- **id** (*Optional*, :ref:`config-id`): Manually specify the ID used for code generation.
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.. _display-max7219digit_lambda:
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Rendering Lambda
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----------------
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The MAX7219 digit is based on the fully fledged :ref:`display-engine`, as it has a concept of individual pixels 8 X 8
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per max7219 chip. In the lambda you're passed a variable called ``it`` as with all other displays. Some "Special"
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commands have been added to the basic display set.
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.. code-block:: yaml
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display:
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- platform: max7219digit
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cs_pin: D8
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num_chips: 4
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lambda: |-
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it.strftime(0, 0, id(digit_font), "%H:%M", id(hass_time).now());
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it.image(24, 0, id(my_image));
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it.line(1, 7, 21, 7);
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font:
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- file: "pixelmix.ttf"
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id: digit_font
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size: 6
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time:
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- platform: homeassistant
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id: hass_time
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image:
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- file: "smile.png"
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id: my_image
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This is roughly the code used to display the MAX7219 pictured in the image.
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Scrolling
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*********
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By default the MAX7219Digit display has scroll enabled. The parameters can be set in the YAML file.
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They can also be changed in the Lambda by adding the following command:
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.. code-block:: cpp
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it.scroll(<on/off>, <mode>, <speed>, <delay>, <dwell>);
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- **on/off** -> switch scrolling on or off, use true or false
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- **mode** -> 0 = Continuous scrolling, 1 = Stop at end and reset
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- **speed** -> Set speed of scrolling (ms for every step of one dot)
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- **delay** -> pause time at start of scrolling
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- **dwell** -> pause at end of scrolling (only in mode 1)
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.. code-block:: yaml
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display:
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- platform: max7219digit
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# ...
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lambda: |-
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# ...
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it.scroll(true, 0, 100, 5000, 1500);
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// OR
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it.scroll(true, 0);
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// OR
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it.scroll(true);
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- The screen does not scroll if the text fits within the screen.
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- ``printdigit("...")`` and ``printdigitf("...")`` the alternative way of displaying text does not scroll
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Screen inversion
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****************
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.. code-block:: yaml
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display:
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- platform: max7219digit
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# ...
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lambda: |-
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it.invert_on_off(true);
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// Print Hello at position 0 (left)
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it.print(0,0, id(digit_font), "Hello!");
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The function ``it.invert_on_off(true);`` will invert the display. So background pixels are on and texts pixels are
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off. ``it.invert_on_off(false);`` sets the display back to normal. In case no argument is used: ``it.inverst_on_off();``
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the inversion will toggle from on to off or visa versa. This will happen every time the display is updated.
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So a blinking effect is created. The background pixels are only set at the next update, the pixels drawn in
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the various function like print, line, etc. are directly influenced by the invert command.
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.. code-block:: yaml
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display:
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- platform: max7219digit
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# ...
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lambda: |-
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it.invert_on_off(true);
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// Print Hello at position 0 (left)
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it.print(0,0, id(digit_font), "Hello!");
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it.line(0, 0, 31, 7, COLOR_OFF);
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This code will only affect the line drawn on the screen. The line will wipe the pixels from top left to right bottom.
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The background is not affected.
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Screen intensity
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****************
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The intensity of the screen can be set "dynamically" within the lambda code with the following command: it.intensity(``0`` .. ``15``).
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.. code-block:: yaml
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display:
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- platform: max7219digit
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# ...
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lambda: |-
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it.intensity(10);
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Screen ON/OFF
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*************
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The display can be switched on and off "dynamically" within the lambda code with the following command: it.turn_on_off(true or false).
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.. code-block:: yaml
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display:
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- platform: max7219digit
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# ...
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lambda: |-
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it.turn_on_off(true);
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For a quick display some additional commands are embedded in the code with a related 8 pixel font. Three methods
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(``printdigit``, ``printdigitf`` and ``strftimedigit``) can be used for displaying characters. Each 8 X 8 grid is used to
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display a single character. So not very space efficient. The format of the command is: ``it.printdigit("1234");`` or
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``it.printdigitf("%s","1234")``;
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Please see :ref:`display-printf` for a quick introduction into the ``printf`` formatting rules and
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:ref:`display-strftime` for an introduction into the ``strftime`` time formatting.
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See Also
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--------
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- :doc:`index`
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- :apiref:`max7219/max7219.h`
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- `MAX7219 Library <https://github.com/nickgammon/MAX7219>`__ by `Nick Gammon <https://github.com/nickgammon>`__
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- :ghedit:`Edit`
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