src/adafruit_blinka/microcontroller/nova/uart.py

   1 # SPDX-FileCopyrightText: 2021 Melissa LeBlanc-Williams for Adafruit Industries
   2 #
   3 # SPDX-License-Identifier: MIT
   4 """UART Class for Binho Nova"""
   5
   6 from adafruit_blinka.microcontroller.nova import Connection
   7
   8
   9 class UART:
  10     """Custom UART Class for Binho Nova"""
  11
  12     ESCAPE_SEQUENCE = "+++UART0"
  13
  14     # pylint: disable=too-many-arguments,unused-argument
  15     def __init__(
  16         self,
  17         portid,
  18         baudrate=9600,
  19         bits=8,
  20         parity=None,
  21         stop=1,
  22         timeout=1000,
  23         read_buf_len=None,
  24         flow=None,
  25     ):
  26         self._nova = Connection.getInstance()
  27
  28         self._id = portid
  29         self._baudrate = baudrate
  30         self._parity = parity
  31         self._bits = bits
  32         self._stop = stop
  33         self._timeout = timeout
  34
  35         if flow is not None:  # default 0
  36             raise NotImplementedError(
  37                 "Parameter '{}' unsupported on Binho Nova".format("flow")
  38             )
  39
  40         self._nova.setOperationMode(self._id, "UART")
  41         self._nova.setBaudRateUART(self._id, baudrate)
  42         self._nova.setDataBitsUART(self._id, bits)
  43         self._nova.setParityUART(self._id, parity)
  44         self._nova.setStopBitsUART(self._id, stop)
  45         self._nova.setEscapeSequenceUART(self._id, UART.ESCAPE_SEQUENCE)
  46         self._nova.beginBridgeUART(self._id)
  47
  48     # pylint: enable=too-many-arguments,unused-argument
  49     def __del__(self):
  50         """Close Nova on delete"""
  51         self.deinit()
  52         self._nova.close()
  53
  54     def deinit(self):
  55         """Deinitialize"""
  56         self._nova.writeBridgeUART(UART.ESCAPE_SEQUENCE)
  57         self._nova.stopBridgeUART(UART.ESCAPE_SEQUENCE)
  58
  59     def read(self, nbytes=None):
  60         """Read data from UART and return it"""
  61         if nbytes is None:
  62             return None
  63         data = bytearray()
  64         for _ in range(nbytes):
  65             data.append(ord(self._nova.readBridgeUART()))
  66         return data
  67
  68     def readinto(self, buf, nbytes=None):
  69         """Read data from UART and into the buffer"""
  70         if nbytes is None:
  71             return None
  72         for _ in range(nbytes):
  73             buf.append(ord(self._nova.readBridgeUART()))
  74         return buf
  75
  76     def readline(self):
  77         """Read a single line of data from UART"""
  78         out = self._nova.readBridgeUART()
  79         line = out
  80         while out != "\r":
  81             out = self._nova.readBridgeUART()
  82             line += out
  83         return line
  84
  85     def write(self, buf):
  86         """Write data from the buffer to UART"""
  87         return self._nova.writeBridgeUART(buf)