src/digitalio.py

   1 """
   2 `digitalio` - Digital input and output control
   3 =================================================
   4
   5 See `CircuitPython:digitalio` in CircuitPython for more details.
   6
   7 * Author(s): cefn
   8 """
   9
  10 from adafruit_blinka.agnostic import board_id, detector
  11
  12 # pylint: disable=ungrouped-imports,wrong-import-position
  13
  14 if detector.chip.BCM2XXX:
  15     from adafruit_blinka.microcontroller.bcm283x.pin import Pin
  16 elif detector.chip.AM33XX:
  17     from adafruit_blinka.microcontroller.am335x.pin import Pin
  18 elif detector.chip.SUN8I:
  19     from adafruit_blinka.microcontroller.allwinner_h3.pin import Pin
  20 elif detector.chip.SAMA5:
  21     from adafruit_blinka.microcontroller.sama5.pin import Pin
  22 elif detector.chip.STM32:
  23     from machine import Pin
  24 from adafruit_blinka import Enum, ContextManaged
  25
  26 class DriveMode(Enum):
  27     PUSH_PULL = None
  28     OPEN_DRAIN = None
  29
  30
  31 DriveMode.PUSH_PULL = DriveMode()
  32 DriveMode.OPEN_DRAIN = DriveMode()
  33
  34
  35 class Direction(Enum):
  36     INPUT = None
  37     OUTPUT = None
  38
  39
  40 Direction.INPUT = Direction()
  41 Direction.OUTPUT = Direction()
  42
  43
  44 class Pull(Enum):
  45     UP = None
  46     DOWN = None
  47     #NONE=None
  48
  49
  50 Pull.UP = Pull()
  51 Pull.DOWN = Pull()
  52
  53 #Pull.NONE = Pull()
  54
  55
  56 class DigitalInOut(ContextManaged):
  57     _pin = None
  58
  59     def __init__(self, pin):
  60         self._pin = Pin(pin.id)
  61         self.direction = Direction.INPUT
  62
  63     def switch_to_output(self, value=False, drive_mode=DriveMode.PUSH_PULL):
  64         self.direction = Direction.OUTPUT
  65         self.value = value
  66         self.drive_mode = drive_mode
  67
  68     def switch_to_input(self, pull=None):
  69         self.direction = Direction.INPUT
  70         self.pull = pull
  71
  72     def deinit(self):
  73         del self._pin
  74
  75     @property
  76     def direction(self):
  77         return self.__direction
  78
  79     @direction.setter
  80     def direction(self, dir):
  81         self.__direction = dir
  82         if dir is Direction.OUTPUT:
  83             self._pin.init(mode=Pin.OUT)
  84             self.value = False
  85             self.drive_mode = DriveMode.PUSH_PULL
  86         elif dir is Direction.INPUT:
  87             self._pin.init(mode=Pin.IN)
  88             self.pull = None
  89         else:
  90             raise AttributeError("Not a Direction")
  91
  92     @property
  93     def value(self):
  94         return self._pin.value() is 1
  95
  96     @value.setter
  97     def value(self, val):
  98         if self.direction is Direction.OUTPUT:
  99             self._pin.value(1 if val else 0)
 100         else:
 101             raise AttributeError("Not an output")
 102
 103     @property
 104     def pull(self):
 105         if self.direction is Direction.INPUT:
 106             return self.__pull
 107         else:
 108             raise AttributeError("Not an input")
 109
 110     @pull.setter
 111     def pull(self, pul):
 112         if self.direction is Direction.INPUT:
 113             self.__pull = pul
 114             if pul is Pull.UP:
 115                 self._pin.init(mode=Pin.IN, pull=Pin.PULL_UP)
 116             elif pul is Pull.DOWN:
 117                 if hasattr(Pin, "PULL_DOWN"):
 118                     self._pin.init(mode=Pin.IN, pull=Pin.PULL_DOWN)
 119                 else:
 120                     raise NotImplementedError("{} unsupported on {}".format(
 121                         Pull.DOWN, board_id))
 122             elif pul is None:
 123                 self._pin.init(mode=Pin.IN, pull=None)
 124             else:
 125                 raise AttributeError("Not a Pull")
 126         else:
 127             raise AttributeError("Not an input")
 128
 129     @property
 130     def drive_mode(self):
 131         if self.direction is Direction.OUTPUT:
 132             return self.__drive_mode  #
 133         else:
 134             raise AttributeError("Not an output")
 135
 136     @drive_mode.setter
 137     def drive_mode(self, mod):
 138         self.__drive_mode = mod
 139         if mod is DriveMode.OPEN_DRAIN:
 140             self._pin.init(mode=Pin.OPEN_DRAIN)
 141         elif mod is DriveMode.PUSH_PULL:
 142             self._pin.init(mode=Pin.OUT)