1  # SPDX-FileCopyrightText: 2017 Tony DiCola for Adafruit Industries
 2  # SPDX-FileCopyrightText: 2019 Carter Nelson
 3  #
 4  # SPDX-License-Identifier: MIT
 5  
 6  """
 7  `mcp23008`
 8  ====================================================
 9  
10  CircuitPython module for the MCP23008 I2C I/O extenders.
11  
12  * Author(s): Tony DiCola
13  """
14  
15  from micropython import const
16  from .mcp230xx import MCP230XX
17  from .digital_inout import DigitalInOut
18  
19  __version__ = "0.0.0-auto.0"
20  __repo__ = "https://github.com/adafruit/Adafruit_CircuitPython_MCP230xx.git"
21  
22  # pylint: disable=bad-whitespace
23  _MCP23008_ADDRESS = const(0x20)
24  _MCP23008_IODIR = const(0x00)
25  _MCP23008_IPOL = const(0x01)
26  _MCP23008_GPINTEN = const(0x02)
27  _MCP23008_DEFVAL = const(0x03)
28  _MCP23008_INTCON = const(0x04)
29  _MCP23008_IOCON = const(0x05)
30  _MCP23008_GPPU = const(0x06)
31  _MCP23008_INTF = const(0x07)
32  _MCP23008_INTCAP = const(0x08)
33  _MCP23008_GPIO = const(0x09)
34  
35  
36  class MCP23008(MCP230XX):
37      """Supports MCP23008 instance on specified I2C bus and optionally
38      at the specified I2C address.
39      """
40  
41      def __init__(self, i2c, address=_MCP23008_ADDRESS):
42          super().__init__(i2c, address)
43  
44          # Reset to all inputs with no pull-ups and no inverted polarity.
45          self.iodir = 0xFF
46          self.gppu = 0x00
47          self._write_u8(_MCP23008_IPOL, 0x00)
48  
49      @property
50      def gpio(self):
51          """The raw GPIO output register.  Each bit represents the
52          output value of the associated pin (0 = low, 1 = high), assuming that
53          pin has been configured as an output previously.
54          """
55          return self._read_u8(_MCP23008_GPIO)
56  
57      @gpio.setter
58      def gpio(self, val):
59          self._write_u8(_MCP23008_GPIO, val)
60  
61      @property
62      def iodir(self):
63          """The raw IODIR direction register.  Each bit represents
64          direction of a pin, either 1 for an input or 0 for an output mode.
65          """
66          return self._read_u8(_MCP23008_IODIR)
67  
68      @iodir.setter
69      def iodir(self, val):
70          self._write_u8(_MCP23008_IODIR, val)
71  
72      @property
73      def gppu(self):
74          """The raw GPPU pull-up register.  Each bit represents
75          if a pull-up is enabled on the specified pin (1 = pull-up enabled,
76          0 = pull-up disabled).  Note pull-down resistors are NOT supported!
77          """
78          return self._read_u8(_MCP23008_GPPU)
79  
80      @gppu.setter
81      def gppu(self, val):
82          self._write_u8(_MCP23008_GPPU, val)
83  
84      def get_pin(self, pin):
85          """Convenience function to create an instance of the DigitalInOut class
86          pointing at the specified pin of this MCP23008 device.
87          """
88          assert 0 <= pin <= 7
89          return DigitalInOut(pin, self)