docs: Generate a separate docs build for each port.

Using Damien's approach where conf.py and topindex.html are
shared by all ports.

1 files changed, 37 insertions, 0 deletions

diff --git a/docs/pyboard/tutorial/debounce.rst b/docs/pyboard/tutorial/debounce.rst
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+Debouncing a pin input
+======================
+
+A pin used as input from a switch or other mechanical device can have a lot
+of noise on it, rapidly changing from low to high when the switch is first
+pressed or released.  This noise can be eliminated using a capacitor (a
+debouncing circuit).  It can also be eliminated using a simple function that
+makes sure the value on the pin is stable.
+
+The following function does just this.  It gets the current value of the given
+pin, and then waits for the value to change.  The new pin value must be stable
+for a continuous 20ms for it to register the change.  You can adjust this time
+(to say 50ms) if you still have noise. ::
+
+    import pyb
+
+    def wait_pin_change(pin):
+        # wait for pin to change value
+        # it needs to be stable for a continuous 20ms
+        cur_value = pin.value()
+        active = 0
+        while active < 20:
+            if pin.value() != cur_value:
+                active += 1
+            else:
+                active = 0
+            pyb.delay(1)
+
+
+Use it something like this::
+
+    import pyb
+
+    pin_x1 = pyb.Pin('X1', pyb.Pin.IN, pyb.Pin.PULL_DOWN)
+    while True:
+        wait_pin_change(pin_x1)
+        pyb.LED(4).toggle()