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 is a character (not to be confused with a string character) which can be 8 or 9 bits wide.
UART objects can be created and initialised using:
from pyb import UART uart = UART(1, 9600) # init with given baudrate uart.init(9600, bits=8, parity=None, stop=1) # init with given parameters
A UART object acts like a stream object and reading and writing is done using the standard stream methods:
uart.read(10) # read 10 characters, returns a bytes object uart.readall() # read all available characters uart.readline() # read a line uart.readinto(buf) # read and store into the given buffer uart.write('abc') # write the 3 characters
Turn off the UART bus.
Read characters. If
nbytesis specified then read at most that many bytes.
Read as much data as possible.
Return value: a bytes object.
Receive a single character on the bus.
Return value: The character read, as an integer. Returns -1 on timeout.
Read bytes into the
nbytesis specified then read at most that many bytes. Otherwise, read at most
Return value: number of bytes read and stored into
Read a line, ending in a newline character.
Return value: the line read.
Send a break condition on the bus. This drives the bus low for a duration of 13 bits. Return value: