X-Git-Url: https://git.ralfj.de/saartuer.git/blobdiff_plain/df7d5268c3bee2e973ca285d97d1a3a77de24743..8b136f42bf0c83f8aee52c315f7dbebc371cce1b:/pins.py?ds=sidebyside

diff --git a/pins.py b/pins.py
new file mode 100644
index 0000000..8b699be
--- /dev/null
+++ b/pins.py
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+import RPi.GPIO as GPIO
+from collections import namedtuple
+from libtuer import ThreadRepeater, logger
+from statemachine import StateMachine
+
+class PinsState():
+	pass
+
+class PinWatcher():
+	def __init__(self, pin, histlen):
+		GPIO.setup(pin, GPIO.IN)
+		assert histlen > 1 # otherwise our logic goes nuts...
+		self.pin = pin
+		self._histlen = histlen
+		# state change detection
+		self.state = None
+		self._newstate = None # != None iff we are currently seeing a state change
+		self._newstatelen = 0 # only valid if newstate != None
+	
+	def read(self):
+		curstate = GPIO.input(self.pin)
+		assert curstate in (0, 1)
+		if curstate != self._state:
+			# the state is about to change
+			if curstate == self._newstate:
+				# we already saw this new state
+				self._newstatelen += 1
+				if self._newstatelen >= self._histlen:
+					# we saw it often enough to declare it the new state
+					self.state = curstate
+					self._newstate = None
+					return True
+			else:
+				# now check for how long we see this new state
+				self._newstate = curstate
+				self._newstatelen = 1
+		else:
+			# old state is preserved
+			self._newstate = None
+		return False
+
+class PinsWatcher():
+	def __init__(self, state_machine):
+		self.pins = {
+			'bell_ringing': PinWatcher(18, 2),
+			'door_closed': PinWatcher(8, 5),
+			'door_locked': PinWatcher(9, 5),
+			'space_active': PinWatcher(10, 5),
+		}
+		self._sm = state_machine
+		
+		# start a thread doing the work
+		self._t = ThreadRepeater(self._read, 0.02)
+		
+	def _read():
+		saw_change = False
+		for name in self.pins.keys():
+			pin = pins[name]
+			if pin.read():
+				saw_change = True
+				logger.debug("Pin %s changed to %d" % (name, pin.state)
+		if not saw_change: return
+		# create return object
+		pinsState = PinsState()
+		for name in self.pins.keys():
+			setattr(pinsState, name, self.pins[name].state)
+		# send it to state machine
+		self._sm.callback(StateMachine.CMD_PINS, pinsState)
+	
+	def stop():
+		self._t.stop()