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80 lines
2.6 KiB
ReStructuredText
80 lines
2.6 KiB
ReStructuredText
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MCP2515
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=======
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.. seo::
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:description: Instructions for setting up the MCP2515 CAN bus platform in ESPHome
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:image: canbus.svg
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:keywords: CAN, MCP2515
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The MCP2515 communicates with ESPHome via the :ref:`SPI bus <spi>`; to use it, you must have at least one
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:ref:`SPI bus <spi>` with both the ``mosi_pin`` and ``miso_pin`` defined in your ESPHome configuration.
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The :ref:`mcp2515-wiring` section below illustrates how to wire up your MCP2515.
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.. code-block:: yaml
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# Example configuration entry
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canbus:
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- platform: mcp2515
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cs_pin: GPIOXX
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can_id: 4
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bit_rate: 50kbps
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on_frame:
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- can_id: 500
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then:
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- lambda: |-
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std::string b(x.begin(), x.end());
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ESP_LOGD("canid 500", "%s", &b[0] );
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- light.turn_off: light_1
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- can_id: 501
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then:
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- light.turn_on:
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id: light_1
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brightness: !lambda "return (x.size() > 0) ? (float) x[0]/255 : 0;"
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Configuration variables:
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------------------------
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- **cs_pin** (**Required**, :ref:`Pin Schema <config-pin_schema>`): Is used to signal to a SPI device when it should
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listen for data on the SPI bus. Each SPI device has its own ``CS`` line. Sometimes also called ``SS``.
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- **clock** (*Optional*, frequency): The frequency of the clock crystal used on the MCP2515 device. One of ``8MHZ``,
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``12MHz``, ``16MHZ`` or ``20MHZ``. Defaults to ``8MHZ``.
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- **mode** (*Optional*, enum): Operating mode. One of:
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- ``NORMAL``: Normal operation. *(default)*
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- ``LOOPBACK``: Loopback mode is useful for testing your connections to/from the device.
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- ``LISTENONLY``: Receive data only.
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- All other options from :ref:`Canbus <config-canbus>`.
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.. note::
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Not all combinations of clock and bitrate are supported. An unsupported combination will not be flagged at
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compile time. Check your ESPHome device's logs for a message like ``Invalid frequency/bitrate combination``
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if you suspect this is an issue.
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.. _mcp2515-wiring:
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Wiring options
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--------------
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The easiest approach is to use fully assembled boards and just add one resistor on the MISO line. This runs MOSI, SCK
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and CS out of specification which is rarely a problem.
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.. figure:: images/canbus_mcp2515_resistor.png
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:align: center
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:target: ../_images/canbus_mcp2515_resistor.png
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A more complex option is to properly convert the 3.3V and 5V logic levels with a level shifter.
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.. figure:: images/canbus_mcp2515_txs0108e.png
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:align: center
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:target: ../_images/canbus_mcp2515_txs0108e.png
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See Also
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--------
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- :doc:`index`
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- :apiref:`canbus/canbus.h`
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- :ghedit:`Edit`
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