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Diffstat (limited to 'docs/library/pyb.UART.rst')
| -rw-r--r-- | docs/library/pyb.UART.rst | 29 |
1 files changed, 24 insertions, 5 deletions
diff --git a/docs/library/pyb.UART.rst b/docs/library/pyb.UART.rst index f9760734bc..66f5cc5da2 100644 --- a/docs/library/pyb.UART.rst +++ b/docs/library/pyb.UART.rst @@ -1,5 +1,5 @@ -class UART --- duplex serial communication bus -============================================== +class UART -- duplex serial communication bus +============================================= UART implements the standard UART/USART duplex serial communications protocol. At the physical level it consists of 2 lines: RX and TX. The unit of communication @@ -36,6 +36,8 @@ To check if there is anything to be read, use:: uart.any() # returns True if any characters waiting +*Note:* The stream functions ``read``, ``write`` etc Are new in Micro Python since v1.3.4. +Earlier versions use ``uart.send`` and ``uart.recv``. Constructors ------------ @@ -56,7 +58,6 @@ Constructors - ``UART(3)`` is on ``YB``: ``(TX, RX) = (Y9, Y10) = (PB10, PB11)`` - ``UART(2)`` is on: ``(TX, RX) = (X3, X4) = (PA2, PA3)`` - Methods ------- @@ -87,13 +88,18 @@ Methods Read characters. If ``nbytes`` is specified then read at most that many bytes. - *Note:* for 9 bit characters each character takes 2 bytes, ``nbytes`` must be even, - and the number of characters is ``nbytes/2``. + *Note:* for 9 bit characters each character takes two bytes, ``nbytes`` must + be even, and the number of characters is ``nbytes/2``. + + Return value: a bytes object containing the bytes read in. Returns ``b''`` + on timeout. .. method:: uart.readall() Read as much data as possible. + Return value: a bytes object. + .. method:: uart.readchar() Receive a single character on the bus. @@ -102,12 +108,25 @@ Methods .. method:: uart.readinto(buf[, nbytes]) + Read bytes into the ``buf``. If ``nbytes`` is specified then read at most + that many bytes. Otherwise, read at most ``len(buf)`` bytes. + + Return value: number of bytes read and stored into ``buf``. .. method:: uart.readline() + Read a line, ending in a newline character. + + Return value: the line read. .. method:: uart.write(buf) + Write the buffer of bytes to the bus. If characters are 7 or 8 bits wide + then each byte is one character. If characters are 9 bits wide then two + bytes are used for each character (little endian), and ``buf`` must contain + an even number of bytes. + + Return value: number of bytes written. .. method:: uart.writechar(char) |