Switch, Pushbutton and Delay_ms: can change callbacks at runtime.

Author: peterhinch

v3/docs/DRIVERS.md

@@ -32,7 +32,8 @@ goes outside defined bounds.
 
 # 2. Installation and usage
 
-The drivers are in the primitives package. To install copy the `primitives`
+The drivers require a daily build of firmware or a release build >=1.15. The
+drivers are in the primitives package. To install copy the `primitives`
 directory and its contents to the target hardware.
 
 Drivers are imported with:
@@ -158,20 +159,21 @@ Constructor arguments:
 
 Methods:
 
- 1. `press_func` Args: `func` (mandatory) a `callable` to run on button push.
- `args` a tuple of arguments for the `callable` (default `()`).
- 2. `release_func` Args: `func` (mandatory) a `callable` to run on button
- release. `args` a tuple of arguments for the `callable` (default `()`).
- 3. `long_func` Args: `func` (mandatory) a `callable` to run on long button
- push. `args` a tuple of arguments for the `callable` (default `()`).
- 4. `double_func` Args: `func` (mandatory) a `callable` to run on double
- push. `args` a tuple of arguments for the `callable` (default `()`).
+ 1. `press_func` Args: `func=False` a `callable` to run on button push,
+ `args=()` a tuple of arguments for the `callable`.
+ 2. `release_func` Args: `func=False` a `callable` to run on button release,
+ `args=()` a tuple of arguments for the `callable`.
+ 3. `long_func` Args: `func=False` a `callable` to run on long button push,
+ `args=()` a tuple of arguments for the `callable`.
+ 4. `double_func` Args: `func=False` a `callable` to run on double push,
+ `args=()` a tuple of arguments for the `callable`.
  5. `__call__` Call syntax e.g. `mybutton()` Returns the logical debounced
  state of the button (`True` corresponds to pressed).
  6. `rawstate()` Returns the logical instantaneous state of the button. There
  is probably no reason to use this.
 
-Methods 1 - 4 should be called before starting the scheduler.
+Methods 1 - 4 may be called at any time. If `False` is passed for a callable,
+any existing callback will be disabled.
 
 Class attributes:
  1. `debounce_ms` Debounce time in ms. Default 50.
@@ -188,12 +190,12 @@ def toggle(led):
     led.toggle()
 
 async def my_app():
+    pin = Pin('X1', Pin.IN, Pin.PULL_UP)  # Pushbutton to gnd
+    red = LED(1)
+    pb = Pushbutton(pin)
+    pb.press_func(toggle, (red,))  # Note how function and args are passed
     await asyncio.sleep(60)  # Dummy
 
-pin = Pin('X1', Pin.IN, Pin.PULL_UP)  # Pushbutton to gnd
-red = LED(1)
-pb = Pushbutton(pin)
-pb.press_func(toggle, (red,))  # Note how function and args are passed
 asyncio.run(my_app())  # Run main application code
 ```
 

v3/docs/TUTORIAL.md

@@ -1125,6 +1125,8 @@ Methods:
  the `Task` instance. This allows the `Task` to be cancelled or awaited.
  6. `wait` One or more tasks may wait on a `Delay_ms` instance. Execution will
  proceed when the instance has timed out.
+ 7. `callback` args `func=None`, `args=()`. Allows the callable and its args to
+ be assigned, reassigned or disabled at run time.
 
 In this example a `Delay_ms` instance is created with the default duration of
 1s. It is repeatedly triggered for 5 secs, preventing the callback from

v3/primitives/delay_ms.py

@@ -65,3 +65,7 @@ def __call__(self):  # Current running status
 
     def rvalue(self):
         return self._retn
+
+    def callback(self, func=None, args=()):
+        self._func = func
+        self._args = args

v3/primitives/pushbutton.py

@@ -1,6 +1,6 @@
 # pushbutton.py
 
-# Copyright (c) 2018-2020 Peter Hinch
+# Copyright (c) 2018-2021 Peter Hinch
 # Released under the MIT License (MIT) - see LICENSE file
 
 import uasyncio as asyncio
@@ -23,34 +23,37 @@ def __init__(self, pin, suppress=False, sense=None):
         self._tf = False
         self._ff = False
         self._df = False
-        self._lf = False
         self._ld = False  # Delay_ms instance for long press
         self._dd = False  # Ditto for doubleclick
         self.sense = pin.value() if sense is None else sense  # Convert from electrical to logical value
         self.state = self.rawstate()  # Initial state
         asyncio.create_task(self.buttoncheck())  # Thread runs forever
 
-    def press_func(self, func, args=()):
+    def press_func(self, func=False, args=()):
         self._tf = func
         self._ta = args
 
-    def release_func(self, func, args=()):
+    def release_func(self, func=False, args=()):
         self._ff = func
         self._fa = args
 
     def double_func(self, func=False, args=()):
         self._df = func
         self._da = args
-        if self._dd:
-            self._dd.stop()
-        self._dd = Delay_ms(self._ddto) if func else False
+        if func:  # If double timer already in place, leave it
+            if not self._dd:
+                self._dd = Delay_ms(self._ddto)
+        else:
+            self._dd = False  # Clearing down double func
 
     def long_func(self, func=False, args=()):
-        self._lf = func
-        self._la = args
-        if self._ld:
-            self._ld.stop()
-        self._ld = Delay_ms(self._lf, self._la) if func else False
+        if func:
+            if self._ld:
+                self._ld.callback(func, args)
+            else:
+                self._ld = Delay_ms(func, args)
+        else:
+            self._ld = False
 
     # Current non-debounced logical button state: True == pressed
     def rawstate(self):
@@ -75,7 +78,7 @@ async def buttoncheck(self):
                 if state:  # Button pressed: launch pressed func
                     if self._tf:
                         launch(self._tf, self._ta)
-                    if self._lf:  # There's a long func: start long press delay
+                    if self._ld:  # There's a long func: start long press delay
                         self._ld.trigger(Pushbutton.long_press_ms)
                     if self._df:
                         if self._dd():  # Second click: timer running

v3/primitives/tests/switches.py

@@ -26,6 +26,7 @@
 test_swcb Switch with callback
 test_btn Pushutton launching coros
 test_btncb Pushbutton launching callbacks
+btn_dynamic Change coros launched at runtime.
 '''
 print(tests)
 
@@ -141,3 +142,40 @@ def test_btncb():
     pb.double_func(toggle, (yellow,))
     pb.long_func(toggle, (blue,))
     run()
+
+# Test for the Pushbutton class where callback coros change dynamically
+def setup(pb, press, release, dbl, lng, t=1000):
+    s = '''
+Functions are changed:
+LED's pulse for 2 seconds
+press pulses blue
+release pulses red
+double click pulses green
+long pulses yellow
+'''
+    pb.press_func(pulse, (press, t))
+    pb.release_func(pulse, (release, t))
+    pb.double_func(pulse, (dbl, t))
+    if lng is not None:
+        pb.long_func(pulse, (lng, t))
+        print(s)
+
+def btn_dynamic():
+    s = '''
+press pulses red
+release pulses green
+double click pulses yellow
+long press changes button functions.
+'''
+    print('Test of pushbutton scheduling coroutines.')
+    print(helptext)
+    print(s)
+    pin = Pin('X1', Pin.IN, Pin.PULL_UP)
+    red = LED(1)
+    green = LED(2)
+    yellow = LED(3)
+    blue = LED(4)
+    pb = Pushbutton(pin)
+    setup(pb, red, green, yellow, None)
+    pb.long_func(setup, (pb, blue, red, green, yellow, 2000))
+    run()