primitives/pushbutton.py

   1 # pushbutton.py
   2
   3 # Copyright (c) 2018-2022 Peter Hinch
   4 # Released under the MIT License (MIT) - see LICENSE file
   5
   6 import uasyncio as asyncio
   7 import utime as time
   8 from . import launch, Delay_ms
   9
  10 try:
  11     from machine import TouchPad
  12 except ImportError:
  13     pass
  14
  15
  16 class Pushbutton:
  17     debounce_ms = 50
  18     long_press_ms = 1000
  19     double_click_ms = 400
  20
  21     def __init__(self, pin, suppress=False, sense=None):
  22         self._pin = pin  # Initialise for input
  23         self._supp = suppress
  24         self._dblpend = False  # Doubleclick waiting for 2nd click
  25         self._dblran = False  # Doubleclick executed user function
  26         self._tf = False
  27         self._ff = False
  28         self._df = False
  29         self._ld = False  # Delay_ms instance for long press
  30         self._dd = False  # Ditto for doubleclick
  31         # Convert from electrical to logical value
  32         self._sense = pin.value() if sense is None else sense
  33         self._state = self.rawstate()  # Initial state
  34         self._run = asyncio.create_task(self._go())  # Thread runs forever
  35
  36     async def _go(self):
  37         while True:
  38             self._check(self.rawstate())
  39             # Ignore state changes until switch has settled. Also avoid hogging CPU.
  40             # See https://github.com/peterhinch/micropython-async/issues/69
  41             await asyncio.sleep_ms(Pushbutton.debounce_ms)
  42
  43     def _check(self, state):
  44         if state == self._state:
  45             return
  46         # State has changed: act on it now.
  47         self._state = state
  48         if state:  # Button pressed: launch pressed func
  49             if self._tf:
  50                 launch(self._tf, self._ta)
  51             if self._ld:  # There's a long func: start long press delay
  52                 self._ld.trigger(Pushbutton.long_press_ms)
  53             if self._df:
  54                 if self._dd():  # Second click: timer running
  55                     self._dd.stop()
  56                     self._dblpend = False
  57                     self._dblran = True  # Prevent suppressed launch on release
  58                     launch(self._df, self._da)
  59                 else:
  60                     # First click: start doubleclick timer
  61                     self._dd.trigger(Pushbutton.double_click_ms)
  62                     self._dblpend = True  # Prevent suppressed launch on release
  63         else:  # Button release. Is there a release func?
  64             if self._ff:
  65                 if self._supp:
  66                     d = self._ld
  67                     # If long delay exists, is running and doubleclick status is OK
  68                     if not self._dblpend and not self._dblran:
  69                         if (d and d()) or not d:
  70                             launch(self._ff, self._fa)
  71                 else:
  72                     launch(self._ff, self._fa)
  73             if self._ld:
  74                 self._ld.stop()  # Avoid interpreting a second click as a long push
  75             self._dblran = False
  76
  77     def _ddto(self):  # Doubleclick timeout: no doubleclick occurred
  78         self._dblpend = False
  79         if self._supp and not self._state:
  80             if not self._ld or (self._ld and not self._ld()):
  81                 launch(self._ff, self._fa)
  82
  83     # ****** API ******
  84     def press_func(self, func=False, args=()):
  85         if func is None:
  86             self.press = asyncio.Event()
  87         self._tf = self.press.set if func is None else func
  88         self._ta = args
  89
  90     def release_func(self, func=False, args=()):
  91         if func is None:
  92             self.release = asyncio.Event()
  93         self._ff = self.release.set if func is None else func
  94         self._fa = args
  95
  96     def double_func(self, func=False, args=()):
  97         if func is None:
  98             self.double = asyncio.Event()
  99             func = self.double.set
 100         self._df = func
 101         self._da = args
 102         if func:  # If double timer already in place, leave it
 103             if not self._dd:
 104                 self._dd = Delay_ms(self._ddto)
 105         else:
 106             self._dd = False  # Clearing down double func
 107
 108     def long_func(self, func=False, args=()):
 109         if func is None:
 110             self.long = asyncio.Event()
 111             func = self.long.set
 112         if func:
 113             if self._ld:
 114                 self._ld.callback(func, args)
 115             else:
 116                 self._ld = Delay_ms(func, args)
 117         else:
 118             self._ld = False
 119
 120     # Current non-debounced logical button state: True == pressed
 121     def rawstate(self):
 122         return bool(self._pin() ^ self._sense)
 123
 124     # Current debounced state of button (True == pressed)
 125     def __call__(self):
 126         return self._state
 127
 128     def deinit(self):
 129         self._run.cancel()
 130
 131
 132 class ESP32Touch(Pushbutton):
 133     thresh = (80 << 8) // 100
 134
 135     @classmethod
 136     def threshold(cls, val):
 137         if not (isinstance(val, int) and 0 < val < 100):
 138             raise ValueError("Threshold must be in range 1-99")
 139         cls.thresh = (val << 8) // 100
 140
 141     def __init__(self, pin, suppress=False):
 142         self._thresh = 0  # Detection threshold
 143         self._rawval = 0
 144         try:
 145             self._pad = TouchPad(pin)
 146         except ValueError:
 147             raise ValueError(pin)  # Let's have a bit of information :)
 148         super().__init__(pin, suppress, False)
 149
 150     # Current logical button state: True == touched
 151     def rawstate(self):
 152         rv = self._pad.read()  # ~220μs
 153         if rv > self._rawval:  # Either initialisation or pad was touched
 154             self._rawval = rv  # when initialised and has now been released
 155             self._thresh = (rv * ESP32Touch.thresh) >> 8
 156             return False  # Untouched
 157         return rv < self._thresh