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ports/mimxrt: Add machine.CAN driver.
Signed-off-by: Kwabena W. Agyeman <kwagyeman@live.com>
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‎docs/library/machine.CAN.rst

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.. currentmodule:: machine
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.. _machine.CAN:
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class CAN -- controller area network communication bus
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======================================================
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CAN implements support for classic CAN controllers.
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At the physical level CAN bus consists of 2 lines: RX and TX. Note that to connect the board to a
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CAN bus you must use a CAN transceiver to convert the CAN logic signals from the board to the correct
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voltage levels on the bus.
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Example usage for classic CAN controller in Loopback (transceiver-less) mode::
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from machine import CAN
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can = CAN(1, CAN.LOOPBACK)
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can.setfilter(0, CAN.LIST32, 0, (123, 124)) # set a filter to receive messages with id=123 and 124
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can.send('message!', 123) # send a message with id 123
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can.recv(0) # receive message on FIFO 0
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The following CAN module functions and their arguments are available
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for classic CAN controllers, unless otherwise stated.
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Availability: IMXRT.
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Constructors
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------------
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.. class:: CAN(bus, ...)
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Construct a CAN object on the given bus. *bus* can be 1-3.
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With no additional parameters, the CAN object is created but not
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initialised (it has the settings from the last initialisation of
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the bus, if any). If extra arguments are given, the bus is initialised.
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See :meth:`CAN.init` for parameters of initialisation.
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Methods
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-------
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.. method:: CAN.init(mode, *, auto_restart=False, baudrate=0)
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Initialise the CAN bus with the given parameters:
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- *mode* is one of: NORMAL, LOOPBACK, SILENT, SILENT_LOOPBACK
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- *auto_restart* sets whether the controller will automatically try and restart
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communications after entering the bus-off state; if this is disabled then
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:meth:`~CAN.restart()` can be used to leave the bus-off state
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- *baudrate* can be 33333, 50000, 62500, 83333, 100000, 125000, 250000, 500000, or 1000000.
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.. method:: CAN.deinit()
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Turn off the CAN bus.
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.. method:: CAN.restart()
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Force a software restart of the CAN controller without resetting its
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configuration.
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If the controller enters the bus-off state then it will no longer participate
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in bus activity. If the controller is not configured to automatically restart
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(see :meth:`~CAN.init()`) then this method can be used to trigger a restart,
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and the controller will follow the CAN protocol to leave the bus-off state and
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go into the error active state.
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.. method:: CAN.state()
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Return the state of the controller. The return value can be one of:
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- ``CAN.STOPPED`` -- the controller is completely off and reset;
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- ``CAN.ERROR_ACTIVE`` -- the controller is on and in the Error Active state
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(both TEC and REC are less than 96);
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- ``CAN.ERROR_WARNING`` -- the controller is on and in the Error Warning state
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(at least one of TEC or REC is 96 or greater);
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- ``CAN.ERROR_PASSIVE`` -- the controller is on and in the Error Passive state
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(at least one of TEC or REC is 128 or greater);
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- ``CAN.BUS_OFF`` -- the controller is on but not participating in bus activity
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(TEC overflowed beyond 255).
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.. method:: CAN.info([list])
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Get information about the controller's error states and TX and RX buffers.
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If *list* is provided then it should be a list object with at least 8 entries,
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which will be filled in with the information. Otherwise a new list will be
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created and filled in. In both cases the return value of the method is the
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populated list.
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The values in the list are:
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- TEC value
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- REC value
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- number of times the controller enterted the Error Warning state (wrapped
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around to 0 after 65535)
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- number of times the controller enterted the Error Passive state (wrapped
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around to 0 after 65535)
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- number of times the controller enterted the Bus Off state (wrapped
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around to 0 after 65535)
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- number of pending TX messages
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- number of pending RX messages on fifo 0
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- number of pending RX messages on fifo 1
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.. method:: CAN.setfilter(bank, mode, fifo, params, *, rtr, extframe=False)
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Configure a filter bank:
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- *bank* is the classic CAN controller filter bank to configure.
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- *mode* is the mode the filter should operate in, see the tables below.
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- *fifo* is which fifo (0 or 1) a message should be stored in, if it is accepted by this filter.
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- *params* is an array of values the defines the filter. The contents of the array depends on the *mode* argument.
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+-----------------------+---------------------------------------------------------+
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|*mode* |Contents of *params* array for classic CAN controller |
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+=======================+=========================================================+
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|CAN.LIST32 or CAN.DUAL |Two 32 bit ids that will be accepted |
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+-----------------------+---------------------------------------------------------+
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- *rtr* For classic CAN controllers, this is an array of booleans that states if
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a filter should accept a remote transmission request message. If this argument
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is not given then it defaults to ``False`` for all entries. The length of the
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array depends on the *mode* argument.
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+-----------------------+----------------------+
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|*mode* |length of *rtr* array |
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+=======================+======================+
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|CAN.LIST32 or CAN.DUAL |2 |
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+-----------------------+----------------------+
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- *extframe* If True the frame will have an extended identifier (29 bits),
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otherwise a standard identifier (11 bits) is used.
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.. method:: CAN.clearfilter(bank)
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Clear and disables a filter bank:
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- *bank* is the classic CAN controller filter bank to clear.
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.. method:: CAN.any(fifo)
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Return ``True`` if any message waiting on the FIFO, else ``False``.
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.. method:: CAN.recv(fifo, list=None, *, timeout=5000)
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Receive data on the bus:
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- *fifo* is an integer, which is the FIFO to receive on
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- *list* is an optional list object to be used as the return value
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- *timeout* is the timeout in milliseconds to wait for the receive.
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Return value: A tuple containing five values.
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- The id of the message.
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- A boolean that indicates if the message ID is standard or extended.
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- A boolean that indicates if the message is an RTR message.
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- The FMI (Filter Match Index) value.
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- An array containing the data.
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If *list* is ``None`` then a new tuple will be allocated, as well as a new
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bytes object to contain the data (as the fifth element in the tuple).
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If *list* is not ``None`` then it should be a list object with a least five
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elements. The fifth element should be a memoryview object which is created
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from either a bytearray or an array of type 'B' or 'b', and this array must
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have enough room for at least 8 bytes. The list object will then be
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populated with the first four return values above, and the memoryview object
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will be resized inplace to the size of the data and filled in with that data.
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The same list and memoryview objects can be reused in subsequent calls to
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this method, providing a way of receiving data without using the heap.
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For example::
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buf = bytearray(8)
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lst = [0, 0, 0, 0, memoryview(buf)]
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# No heap memory is allocated in the following call
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can.recv(0, lst)
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.. method:: CAN.send(data, id, *, timeout=0, rtr=False, extframe=False)
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Send a message on the bus:
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- *data* is the data to send (an integer to send, or a buffer object).
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- *id* is the id of the message to be sent.
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- *timeout* is the timeout in milliseconds to wait for the send.
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- *rtr* is a boolean that specifies if the message shall be sent as
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a remote transmission request. If *rtr* is True then only the length
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of *data* is used to fill in the DLC slot of the frame; the actual
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bytes in *data* are unused.
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- *extframe* if True the frame will have an extended identifier (29 bits),
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otherwise a standard identifier (11 bits) is used.
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If timeout is 0 the message is placed in a buffer in one of three hardware
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buffers and the method returns immediately. If all three buffers are in use
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an exception is thrown. If timeout is not 0, the method waits until the
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message is transmitted. If the message can't be transmitted within the
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specified time an exception is thrown.
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Return value: ``None``.
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.. method:: CAN.rxcallback(fifo, fun)
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Register a function to be called when a message is accepted into a empty fifo:
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- *fifo* is the receiving fifo.
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- *fun* is the function to be called when the fifo becomes non empty.
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The callback function takes two arguments the first is the can object it self the second is
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a integer that indicates the reason for the callback.
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+--------+------------------------------------------------+
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| Reason | |
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+========+================================================+
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| 0 | A message has been accepted into a empty FIFO. |
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+--------+------------------------------------------------+
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| 1 | The FIFO is full |
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+--------+------------------------------------------------+
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| 2 | A message has been lost due to a full FIFO |
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+--------+------------------------------------------------+
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Example use of rxcallback::
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def cb0(bus, reason):
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print('cb0')
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if reason == 0:
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print('pending')
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if reason == 1:
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print('full')
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if reason == 2:
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print('overflow')
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can = CAN(1, CAN.LOOPBACK)
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can.rxcallback(0, cb0)
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Constants
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---------
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.. data:: CAN.NORMAL
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CAN.LOOPBACK
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CAN.SILENT
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CAN.SILENT_LOOPBACK
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The mode of the CAN bus used in :meth:`~CAN.init()`.
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.. data:: CAN.STOPPED
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CAN.ERROR_ACTIVE
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CAN.ERROR_WARNING
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CAN.ERROR_PASSIVE
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CAN.BUS_OFF
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Possible states of the CAN controller returned from :meth:`~CAN.state()`.
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.. data:: CAN.LIST32
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CAN.DUAL
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The operation mode of a filter used in :meth:`~CAN.setfilter()` for classic CAN.

‎docs/library/machine.rst

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machine.Signal.rst
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machine.ADC.rst
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machine.ADCBlock.rst
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machine.CAN.rst
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machine.PWM.rst
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machine.UART.rst
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machine.SPI.rst

‎ports/mimxrt/Makefile

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SRC_HAL_IMX_C += $(MCU_DIR)/drivers/fsl_usdhc.c
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endif
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ifeq ($(MICROPY_HW_ENABLE_CAN),1)
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SRC_HAL_IMX_C += $(MCU_DIR)/drivers/fsl_flexcan.c
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endif
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ifeq ($(MCU_SERIES),$(filter $(MCU_SERIES), MIMXRT1015 MIMXRT1021 MIMXRT1052 MIMXRT1062 MIMXRT1064 MIMXRT1176))
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SRC_HAL_IMX_C += \
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$(MCU_DIR)/drivers/fsl_qtmr.c \
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led.c \
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machine_adc.c \
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machine_bitstream.c \
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machine_can.c \
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machine_i2c.c \
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machine_i2s.c \
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machine_led.c \
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MICROPY_HW_SDRAM_AVAIL ?= 0
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MICROPY_HW_SDRAM_SIZE ?= 0
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MICROPY_PY_MACHINE_SDCARD ?= 0
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MICROPY_HW_ENABLE_CAN ?= 0
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# Configure default compiler flags
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CFLAGS += \
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-DMICROPY_HW_SDRAM_AVAIL=$(MICROPY_HW_SDRAM_AVAIL) \
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-DMICROPY_HW_SDRAM_SIZE=$(MICROPY_HW_SDRAM_SIZE) \
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-DMICROPY_PY_MACHINE_SDCARD=$(MICROPY_PY_MACHINE_SDCARD) \
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-DMICROPY_HW_ENABLE_CAN=$(MICROPY_HW_ENABLE_CAN) \
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-DSPI_RETRY_TIMES=1000000 \
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-DUART_RETRY_TIMES=1000000 \
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-DXIP_BOOT_HEADER_ENABLE=1 \

‎ports/mimxrt/README.md

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Features:
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- REPL over USB VCP
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- machine.ADC
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- machine.CAN
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- machine.I2C
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- machine.LED
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- machine.Pin
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Known issues:
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TODO:
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- More peripherals (Counter, I2S, CAN, etc)
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- More peripherals (Counter, I2S, etc)
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- More Python options
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## Build Instructions

‎ports/mimxrt/boards/MIMXRT1020_EVK/mpconfigboard.h

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{ 0 }, { 0 }, \
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{ IOMUXC_GPIO_SD_B1_02_LPI2C4_SCL }, { IOMUXC_GPIO_SD_B1_03_LPI2C4_SDA },
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#define MICROPY_HW_CAN_INDEX { 1 }
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#define MICROPY_HW_NUM_CAN_IRQS (1)
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#define IOMUX_TABLE_CAN \
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{ IOMUXC_GPIO_SD_B1_00_FLEXCAN1_TX }, { IOMUXC_GPIO_SD_B1_01_FLEXCAN1_RX },
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#define MICROPY_PY_MACHINE_I2S (1)
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#define MICROPY_HW_I2S_NUM (1)
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#define I2S_CLOCK_MUX { 0, kCLOCK_Sai1Mux, kCLOCK_Sai2Mux }

‎ports/mimxrt/boards/MIMXRT1020_EVK/mpconfigboard.mk

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MICROPY_FLOAT_IMPL = double
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MICROPY_PY_MACHINE_SDCARD = 1
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MICROPY_HW_ENABLE_CAN = 1
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MICROPY_HW_FLASH_TYPE = qspi_nor_flash
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MICROPY_HW_FLASH_SIZE = 0x800000 # 8MB
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‎ports/mimxrt/boards/MIMXRT1050_EVK/mpconfigboard.h

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{ 0 }, { 0 }, \
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{ IOMUXC_GPIO_AD_B1_07_LPI2C3_SCL }, { IOMUXC_GPIO_AD_B1_06_LPI2C3_SDA },
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#define MICROPY_HW_CAN_INDEX { 2 }
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#define MICROPY_HW_NUM_CAN_IRQS (1)
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#define IOMUX_TABLE_CAN \
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{ 0 }, { 0 }, \
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{ IOMUXC_GPIO_AD_B0_14_FLEXCAN2_TX }, { IOMUXC_GPIO_AD_B0_15_FLEXCAN2_RX },
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#define MICROPY_PY_MACHINE_I2S (1)
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#define MICROPY_HW_I2S_NUM (1)
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#define I2S_CLOCK_MUX { 0, kCLOCK_Sai1Mux, kCLOCK_Sai2Mux }

‎ports/mimxrt/boards/MIMXRT1050_EVK/mpconfigboard.mk

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MICROPY_FLOAT_IMPL = double
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MICROPY_PY_MACHINE_SDCARD = 1
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MICROPY_HW_ENABLE_CAN = 1
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MICROPY_HW_FLASH_TYPE = qspi_hyper_flash
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MICROPY_HW_FLASH_SIZE = 0x4000000 # 64MB
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‎ports/mimxrt/boards/MIMXRT1060_EVK/mpconfigboard.h

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{ 0 }, { 0 }, \
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{ IOMUXC_GPIO_AD_B1_07_LPI2C3_SCL }, { IOMUXC_GPIO_AD_B1_06_LPI2C3_SDA },
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#define MICROPY_HW_CAN_INDEX { 2 }
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#define MICROPY_HW_NUM_CAN_IRQS (1)
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#define IOMUX_TABLE_CAN \
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{ 0 }, { 0 }, \
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{ IOMUXC_GPIO_AD_B0_14_FLEXCAN2_TX }, { IOMUXC_GPIO_AD_B0_15_FLEXCAN2_RX },
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#define MICROPY_PY_MACHINE_I2S (1)
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#define MICROPY_HW_I2S_NUM (1)
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#define I2S_CLOCK_MUX { 0, kCLOCK_Sai1Mux, kCLOCK_Sai2Mux }

‎ports/mimxrt/boards/MIMXRT1060_EVK/mpconfigboard.mk

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MICROPY_FLOAT_IMPL = double
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MICROPY_PY_MACHINE_SDCARD = 1
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MICROPY_HW_ENABLE_CAN = 1
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MICROPY_HW_FLASH_TYPE = qspi_nor_flash
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MICROPY_HW_FLASH_SIZE = 0x800000 # 8MB
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