105 lines
3.2 KiB
ReStructuredText
105 lines
3.2 KiB
ReStructuredText
class USB_VCP -- USB virtual comm port
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======================================
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The USB_VCP class allows creation of an object representing the USB
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virtual comm port. It can be used to read and write data over USB to
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the connected host.
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Constructors
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------------
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.. class:: pyb.USB_VCP()
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Create a new USB_VCP object.
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Methods
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-------
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.. method:: usb_vcp.setinterrupt(chr)
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Set the character which interrupts running Python code. This is set
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to 3 (CTRL-C) by default, and when a CTRL-C character is received over
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the USB VCP port, a KeyboardInterrupt exception is raised.
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Set to -1 to disable this interrupt feature. This is useful when you
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want to send raw bytes over the USB VCP port.
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.. method:: usb_vcp.isconnected()
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Return ``True`` if USB is connected as a serial device, else ``False``.
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.. method:: usb_vcp.any()
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Return ``True`` if any characters waiting, else ``False``.
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.. method:: usb_vcp.close()
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This method does nothing. It exists so the USB_VCP object can act as
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a file.
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.. method:: usb_vcp.read([nbytes])
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Read at most ``nbytes`` from the serial device and return them as a
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bytes object. If ``nbytes`` is not specified then the method acts as
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``readall()``. USB_VCP stream implicitly works in non-blocking mode,
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so if no pending data available, this method will return immediately
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with ``None`` value.
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.. method:: usb_vcp.readall()
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Read all available bytes from the serial device and return them as
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a bytes object, or ``None`` if no pending data available.
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.. method:: usb_vcp.readinto(buf, [maxlen])
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Read bytes from the serial device and store them into ``buf``, which
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should be a buffer-like object. At most ``len(buf)`` bytes are read.
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If ``maxlen`` is given and then at most ``min(maxlen, len(buf))`` bytes
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are read.
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Returns the number of bytes read and stored into ``buf`` or ``None``
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if no pending data available.
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.. method:: usb_vcp.readline()
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Read a whole line from the serial device.
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Returns a bytes object containing the data, including the trailing
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newline character or ``None`` if no pending data available.
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.. method:: usb_vcp.readlines()
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Read as much data as possible from the serial device, breaking it into
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lines.
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Returns a list of bytes objects, each object being one of the lines.
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Each line will include the newline character.
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.. method:: usb_vcp.write(buf)
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Write the bytes from ``buf`` to the serial device.
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Returns the number of bytes written.
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.. method:: usb_vcp.recv(data, \*, timeout=5000)
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Receive data on the bus:
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- ``data`` can be an integer, which is the number of bytes to receive,
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or a mutable buffer, which will be filled with received bytes.
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- ``timeout`` is the timeout in milliseconds to wait for the receive.
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Return value: if ``data`` is an integer then a new buffer of the bytes received,
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otherwise the number of bytes read into ``data`` is returned.
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.. method:: usb_vcp.send(data, \*, timeout=5000)
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Send data over the USB VCP:
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- ``data`` is the data to send (an integer to send, or a buffer object).
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- ``timeout`` is the timeout in milliseconds to wait for the send.
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Return value: number of bytes sent.
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