Intial working version

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+#The recipe gives simple implementation of a Discrete Proportional-Integral-Derivative (PID) controller. PID controller gives output value for error between desired reference input and measurement feedback to minimize error value.
+#More information: http://en.wikipedia.org/wiki/PID_controller
+#
+#cnr437@gmail.com
+#
+#######	Example	#########
+#
+#p=PID(3.0,0.4,1.2)
+#p.setPoint(5.0)
+#while True:
+#     pid = p.update(measurement_value)
+#
+#
+
+
+class PID:
+	"""
+	Discrete PID control
+	"""
+
+	def __init__(self, P=2.0, I=0.0, D=1.0, Derivator=0, Integrator=0, Integrator_max=500, Integrator_min=-500, Set_Point=0.0):
+
+		self.Kp=P
+		self.Ki=I
+		self.Kd=D
+		self.Derivator=Derivator
+		self.Integrator=Integrator
+		self.Integrator_max=Integrator_max
+		self.Integrator_min=Integrator_min
+
+		self.set_point=Set_Point
+		self.error=0.0
+
+	def update(self,current_value):
+		"""
+		Calculate PID output value for given reference input and feedback
+		"""
+
+		self.error = self.set_point - current_value
+
+		self.P_value = self.Kp * self.error
+		self.D_value = self.Kd * ( self.error - self.Derivator)
+		self.Derivator = self.error
+
+		self.Integrator = self.Integrator + self.error
+
+		if self.Integrator > self.Integrator_max:
+			self.Integrator = self.Integrator_max
+		elif self.Integrator < self.Integrator_min:
+			self.Integrator = self.Integrator_min
+
+		self.I_value = self.Integrator * self.Ki
+
+		PID = self.P_value + self.I_value + self.D_value
+
+		return PID
+
+	def setPoint(self,set_point):
+		"""
+		Initilize the setpoint of PID
+		"""
+		self.set_point = set_point
+		self.Integrator=0
+		self.Derivator=0
+
+	def setIntegrator(self, Integrator):
+		self.Integrator = Integrator
+
+	def setDerivator(self, Derivator):
+		self.Derivator = Derivator
+
+	def setKp(self,P):
+		self.Kp=P
+
+	def setKi(self,I):
+		self.Ki=I
+
+	def setKd(self,D):
+		self.Kd=D
+
+	def getPoint(self):
+		return self.set_point
+
+	def getError(self):
+		return self.error
+
+	def getIntegrator(self):
+		return self.Integrator
+
+	def getDerivator(self):
+		return self.Derivator