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.TEGRAXXX:
  23     from adafruit_blinka.microcontroller.tegra.pin import Pin
  24 elif detector.chip.STM32:
  25     from machine import Pin
  26 from adafruit_blinka import Enum, ContextManaged
  27
  28 class DriveMode(Enum):
  29     PUSH_PULL = None
  30     OPEN_DRAIN = None
  31
  32
  33 DriveMode.PUSH_PULL = DriveMode()
  34 DriveMode.OPEN_DRAIN = DriveMode()
  35
  36
  37 class Direction(Enum):
  38     INPUT = None
  39     OUTPUT = None
  40
  41
  42 Direction.INPUT = Direction()
  43 Direction.OUTPUT = Direction()
  44
  45
  46 class Pull(Enum):
  47     UP = None
  48     DOWN = None
  49     #NONE=None
  50
  51
  52 Pull.UP = Pull()
  53 Pull.DOWN = Pull()
  54
  55 #Pull.NONE = Pull()
  56
  57 class DigitalInOut(ContextManaged):
  58     _pin = None
  59
  60     def __init__(self, pin):
  61         self._pin = Pin(pin.id)
  62         self.direction = Direction.INPUT
  63
  64     def switch_to_output(self, value=False, drive_mode=DriveMode.PUSH_PULL):
  65         self.direction = Direction.OUTPUT
  66         self.value = value
  67         self.drive_mode = drive_mode
  68
  69     def switch_to_input(self, pull=None):
  70         self.direction = Direction.INPUT
  71         self.pull = pull
  72
  73     def deinit(self):
  74         del self._pin
  75
  76     def cleanup(self, channel=None):
  77         if channel == self:
  78             Pin.cleanup(self._pin, self._pin)
  79         else:
  80             Pin.cleanup(self, channel)
  81
  82     @property
  83     def direction(self):
  84         return self.__direction
  85
  86     @direction.setter
  87     def direction(self, dir):
  88         self.__direction = dir
  89         if dir is Direction.OUTPUT:
  90             self._pin.init(mode=Pin.OUT)
  91             self.value = False
  92             self.drive_mode = DriveMode.PUSH_PULL
  93         elif dir is Direction.INPUT:
  94             self._pin.init(mode=Pin.IN)
  95             self.pull = None
  96         else:
  97             raise AttributeError("Not a Direction")
  98
  99     @property
 100     def value(self):
 101         return self._pin.value() is 1
 102
 103     @value.setter
 104     def value(self, val):
 105         if self.direction is Direction.OUTPUT:
 106             self._pin.value(1 if val else 0)
 107         else:
 108             raise AttributeError("Not an output")
 109
 110     @property
 111     def pull(self):
 112         if self.direction is Direction.INPUT:
 113             return self.__pull
 114         else:
 115             raise AttributeError("Not an input")
 116
 117     @pull.setter
 118     def pull(self, pul):
 119         if self.direction is Direction.INPUT:
 120             self.__pull = pul
 121             if pul is Pull.UP:
 122                 self._pin.init(mode=Pin.IN, pull=Pin.PULL_UP)
 123             elif pul is Pull.DOWN:
 124                 if hasattr(Pin, "PULL_DOWN"):
 125                     self._pin.init(mode=Pin.IN, pull=Pin.PULL_DOWN)
 126                 else:
 127                     raise NotImplementedError("{} unsupported on {}".format(
 128                         Pull.DOWN, board_id))
 129             elif pul is None:
 130                 self._pin.init(mode=Pin.IN, pull=None)
 131             else:
 132                 raise AttributeError("Not a Pull")
 133         else:
 134             raise AttributeError("Not an input")
 135
 136     @property
 137     def drive_mode(self):
 138         if self.direction is Direction.OUTPUT:
 139             return self.__drive_mode  #
 140         else:
 141             raise AttributeError("Not an output")
 142
 143     @drive_mode.setter
 144     def drive_mode(self, mod):
 145         self.__drive_mode = mod
 146         if mod is DriveMode.OPEN_DRAIN:
 147             self._pin.init(mode=Pin.OPEN_DRAIN)
 148         elif mod is DriveMode.PUSH_PULL:
 149             self._pin.init(mode=Pin.OUT)