- improved controller

- plant: added duty cycle to heater control

git-svn-id: http://moon:8086/svn/projects/HendiControl@271 fda53097-d464-4ada-af97-ba876c37ca34

Control/brewpi/plant.py

@@ -11,6 +11,9 @@ class Plant(APlant):
 		self.tempsensor = Max31865()
 		self.P = 0
 		self.isOn = False
+		self.cycleTime = 10
+		self.dutyCycle = 1
+		self.cycleCounter = 0
 
 	def activate(self, enable=True):
 		if enable == True:
@@ -20,20 +23,29 @@ class Plant(APlant):
 			self.heater.setSwitch(enable)
 			self.heater.remoteEnable(enable)
 
-	def process(self):
-		pass
+	def process(self, dt=1):
+		isOn = self.isOn
+		self.cycleCounter += dt
+		if self.cycleCounter >= self.cycleTime:
+			self.cycleCounter -= self.cycleTime
+			isOn = 0
+
+		if self.cycleCounter >= (self.cycleTime * (1-self.dutyCycle)):
+			if not isOn:
+				isOn = 1
+
+		if self.isOn != isOn:
+			if isOn:
+				self.heater.setSwitch(True)
+			else:
+				self.heater.setSwitch(False)
+
+		self.isOn = isOn
 
 	def setPower(self, power_w):
 		self.P = power_w
-		self.heater.setPowerWatts(power_w)
-		if power_w < 250:
-			if self.isOn:
-				self.heater.setSwitch(False)
-				self.isOn = False
-		elif power_w >= 500:
-			if not self.isOn:
-				self.heater.setSwitch(True)
-				self.isOn = True
+		self.heater.setPowerWatts(max(500, power_w))
+		self.dutyCycle = min(1, power_w / 500)
 
 	def getPower(self):
 		return self.heater.getPowerWatts()