MAX7219 7-Segment Display ========================= .. seo:: :description: Instructions for setting up MAX7219 7-segment displays. :image: max7219.jpg The ``max7219`` display platform allows you to use MAX7219 7-segment display drivers ( `datasheet `__, `hobbycomponents `__) with ESPHome. Please note that this integration is *only* for 7-segment display, not matrix configurations. .. figure:: images/max7219-full.jpg :align: center :width: 75.0% MAX7219 7-Segment Display. As the communication with the MAX7219 is done using SPI for this integration, you need to have an :ref:`SPI bus ` in your configuration with both the **mosi_pin** set (miso_pin is not required). Connect VCC to 3.3V (the manufacturer recommends 4+ V, but 3.3V seems to work fine), DIN to your ``mosi_pin`` and CS to your set ``cs_pin`` and finally GND to GND. You can even daisy-chain multiple MAX7219s by connecting the DOUT of the previous chip in the chain to the next DIN. With more than ~3 chips the 3.3V will probably not be enough, so then you will have to potentially use a logic level converted. .. code-block:: yaml # Example configuration entry spi: clk_pin: D0 mosi_pin: D1 display: - platform: max7219 cs_pin: D2 num_chips: 1 lambda: |- it.print("01234567"); Configuration variables: ------------------------ - **cs_pin** (**Required**, :ref:`Pin Schema `): The pin you have the CS line hooked up to. - **num_chips** (*Optional*, integer): The number of chips you wish to use for daisy chaining. Defaults to ``1``. - **intensity** (*Optional*, integer): The intensity with which the MAX7219 should drive the outputs. Range is from 0 (least intense) to 15 (the default). - **lambda** (*Optional*, :ref:`lambda `): The lambda to use for rendering the content on the MAX7219. See :ref:`display-max7219_lambda` for more information. - **update_interval** (*Optional*, :ref:`config-time`): The interval to re-draw the screen. Defaults to ``1s``. - **spi_id** (*Optional*, :ref:`config-id`): Manually specify the ID of the :ref:`SPI Component ` if you want to use multiple SPI buses. - **id** (*Optional*, :ref:`config-id`): Manually specify the ID used for code generation. .. _display-max7219_lambda: Rendering Lambda ---------------- The MAX7219 has a similar API to the fully fledged :ref:`display-engine`, but it's only a subset as the MAX7219 7-segment displays don't have a concept of individual pixels. In the lambda you're passed a variable called ``it`` as with all other displays. In this case however, ``it`` is an MAX7219 instance (see API Reference). The most basic operation with the MAX7219 is wiring a simple number to the screen as in the configuration example at the top of this page. But even though you're passing in a string (here ``"01234567"``), ESPHome converts it into a representation that the MAX7219 can understand: The exact pixels that should be turned on. And of course, not all characters can be represented. You can see a full list of characters :ref:`below `. Each of the three methods (``print``, ``printf`` and ``strftime``) all optionally take a position argument at the beginning which can be used to print the text at a specific position. This argument is ``0`` by default which means the first character of the first MAX7219. For example to start the first character of your text at the end of the first MAX7219, you would write ``it.print(7, "0");``. Also note that the ``.`` (dot) character is special because when ESPHome encounters it in the string the dot segment of the previous position will be enabled. .. code-block:: yaml display: - platform: max7219 # ... lambda: |- // Print 0 at position 0 (left) it.print("0"); // Result: "0 " // Print 1 at position 1 (second character) it.print(1, "1"); // Result: "01 " // Let's write a sensor value (let's assume it's 42.1) it.printf(3, "%.1f", id(my_sensor).state); // Result: "01 42.1 " (the dot will appear on the "2" segment) // Overwrite the previous content with blank it.print(" "); // Print a right-padded sensor value with 0 digits after the decimal it.printf("SENS%4.0f", id(my_sensor).state); // Result: "SENS 42" // Print the current time it.print(" "); it.strftime("%H.%M.%S"); // Result for 10:06:42 -> "10.06.42 " Please see :ref:`display-printf` for a quick introduction into the ``printf`` formatting rules and :ref:`display-strftime` for an introduction into the ``strftime`` time formatting. .. _display-max7219_characters: All 7-Segment Characters ------------------------ ============================== ============================== **MAX7219 Representation** **Character** ------------------------------ ------------------------------ |max721900| *(space)* ------------------------------ ------------------------------ |max721980| ``.`` ------------------------------ ------------------------------ |max7219B0| ``!`` ------------------------------ ------------------------------ |max72197E| ``0``, ``O`` ------------------------------ ------------------------------ |max721930| ``1``, ``I`` ------------------------------ ------------------------------ |max72196D| ``2``, ``Z`` ------------------------------ ------------------------------ |max721979| ``3`` ------------------------------ ------------------------------ |max721933| ``4`` ------------------------------ ------------------------------ |max72195B| ``5``, ``S``, ``s`` ------------------------------ ------------------------------ |max72195F| ``6`` ------------------------------ ------------------------------ |max721970| ``7`` ------------------------------ ------------------------------ |max72197F| ``8`` ------------------------------ ------------------------------ |max721973| ``9`` ------------------------------ ------------------------------ |max721937| ``H`` ------------------------------ ------------------------------ |max72194E| ``(``, ``[``, ``C`` ------------------------------ ------------------------------ |max721931| ``{`` ------------------------------ ------------------------------ |max721978| ``)``, ``]`` ------------------------------ ------------------------------ |max721907| ``}``, ``T``, ``t`` ------------------------------ ------------------------------ |max721920| ``\``` ------------------------------ ------------------------------ |max721902| ``'`` ------------------------------ ------------------------------ |max721922| ``"`` ------------------------------ ------------------------------ |max72196F| ``@`` ------------------------------ ------------------------------ |max721965| ``?`` ------------------------------ ------------------------------ |max721910| ``,``, ``i`` ------------------------------ ------------------------------ |max721949| ``%`` ------------------------------ ------------------------------ |max721940| ``*`` ------------------------------ ------------------------------ |max721948| ``:`` ------------------------------ ------------------------------ |max721958| ``;`` ------------------------------ ------------------------------ |max721977| ``A``, ``a`` ------------------------------ ------------------------------ |max72191F| ``B``, ``b`` ------------------------------ ------------------------------ |max72193D| ``D``, ``d`` ------------------------------ ------------------------------ |max72194F| ``E``, ``e`` ------------------------------ ------------------------------ |max721947| ``F``, ``f`` ------------------------------ ------------------------------ |max72195E| ``G``, ``g`` ------------------------------ ------------------------------ |max72193C| ``J``, ``j`` ------------------------------ ------------------------------ |max72190E| ``L``, ``l`` ------------------------------ ------------------------------ |max721915| ``N``, ``n`` ------------------------------ ------------------------------ |max721967| ``P``, ``p`` ------------------------------ ------------------------------ |max7219FE| ``Q`` ------------------------------ ------------------------------ |max721905| ``R``, ``r`` ------------------------------ ------------------------------ |max72193E| ``U``, ``V`` ------------------------------ ------------------------------ |max72193F| ``W`` ------------------------------ ------------------------------ |max721927| ``Y``, ``y`` ------------------------------ ------------------------------ |max721901| ``-`` ------------------------------ ------------------------------ |max721908| ``_`` ------------------------------ ------------------------------ |max721906| ``|`` ------------------------------ ------------------------------ |max72190D| ``c`` ------------------------------ ------------------------------ |max721917| ``h`` ------------------------------ ------------------------------ |max72191D| ``o`` ------------------------------ ------------------------------ |max72191C| ``u``, ``v`` ============================== ============================== .. |max721900| image:: images/max7219/seg00.svg :class: component-image .. |max721980| image:: images/max7219/seg80.svg :class: component-image .. |max7219B0| image:: images/max7219/segB0.svg :class: component-image .. |max72197E| image:: images/max7219/seg7E.svg :class: component-image .. |max721930| image:: images/max7219/seg30.svg :class: component-image .. |max72196D| image:: images/max7219/seg6D.svg :class: component-image .. |max721979| image:: images/max7219/seg79.svg :class: component-image .. |max721933| image:: images/max7219/seg33.svg :class: component-image .. |max72195B| image:: images/max7219/seg5B.svg :class: component-image .. |max72195F| image:: images/max7219/seg5F.svg :class: component-image .. |max721970| image:: images/max7219/seg70.svg :class: component-image .. |max72197F| image:: images/max7219/seg7F.svg :class: component-image .. |max721973| image:: images/max7219/seg73.svg :class: component-image .. |max721937| image:: images/max7219/seg37.svg :class: component-image .. |max72194E| image:: images/max7219/seg4E.svg :class: component-image .. |max721931| image:: images/max7219/seg31.svg :class: component-image .. |max721978| image:: images/max7219/seg78.svg :class: component-image .. |max721907| image:: images/max7219/seg07.svg :class: component-image .. |max721920| image:: images/max7219/seg20.svg :class: component-image .. |max721902| image:: images/max7219/seg02.svg :class: component-image .. |max721922| image:: images/max7219/seg22.svg :class: component-image .. |max72196F| image:: images/max7219/seg6F.svg :class: component-image .. |max721965| image:: images/max7219/seg65.svg :class: component-image .. |max721910| image:: images/max7219/seg10.svg :class: component-image .. |max721949| image:: images/max7219/seg49.svg :class: component-image .. |max721940| image:: images/max7219/seg40.svg :class: component-image .. |max721948| image:: images/max7219/seg48.svg :class: component-image .. |max721958| image:: images/max7219/seg58.svg :class: component-image .. |max721977| image:: images/max7219/seg77.svg :class: component-image .. |max72191F| image:: images/max7219/seg1F.svg :class: component-image .. |max72193D| image:: images/max7219/seg3D.svg :class: component-image .. |max72194F| image:: images/max7219/seg4F.svg :class: component-image .. |max721947| image:: images/max7219/seg47.svg :class: component-image .. |max72195E| image:: images/max7219/seg5E.svg :class: component-image .. |max72193C| image:: images/max7219/seg3C.svg :class: component-image .. |max72190E| image:: images/max7219/seg0E.svg :class: component-image .. |max721915| image:: images/max7219/seg15.svg :class: component-image .. |max721967| image:: images/max7219/seg67.svg :class: component-image .. |max7219FE| image:: images/max7219/segFE.svg :class: component-image .. |max721905| image:: images/max7219/seg05.svg :class: component-image .. |max72193E| image:: images/max7219/seg3E.svg :class: component-image .. |max72193F| image:: images/max7219/seg3F.svg :class: component-image .. |max721927| image:: images/max7219/seg27.svg :class: component-image .. |max721901| image:: images/max7219/seg01.svg :class: component-image .. |max721908| image:: images/max7219/seg08.svg :class: component-image .. |max721906| image:: images/max7219/seg06.svg :class: component-image .. |max72190D| image:: images/max7219/seg0D.svg :class: component-image .. |max721917| image:: images/max7219/seg17.svg :class: component-image .. |max72191D| image:: images/max7219/seg1D.svg :class: component-image .. |max72191C| image:: images/max7219/seg1C.svg :class: component-image .. note:: Original 7-segment display base image taken from Wikipedia at https://de.wikipedia.org/wiki/Datei:7_Segment_Display.svg by user `h2g2bob `__ under `Creative Commons BY-SA 3.0 `__ and modified for this documentation. See Also -------- - :doc:`index` - :apiref:`display/max7219.h` - `MAX7219 Library `__ by `Nick Gammon `__ - :ghedit:`Edit` .. disqus::