adding restart profile functionality

config.py

@@ -13,7 +13,7 @@ log_format = '%(asctime)s %(levelname)s %(name)s: %(message)s'
 
 ### Server
 listening_ip = "0.0.0.0"
-listening_port = 8081
+listening_port = 8082
 
 ### Cost Estimate
 kwh_rate        = 0.1319  # Rate in currency_type to calculate cost to run job
@@ -65,7 +65,7 @@ sensor_time_wait = 2
 # your specific kiln. Note that the integral pid_ki is
 # inverted so that a smaller number means more integral action.
 pid_kp = 25   # Proportional 25,200,200
-pid_ki = 20   # Integral
+pid_ki = 10   # Integral
 pid_kd = 200  # Derivative
 
 
@@ -82,10 +82,10 @@ stop_integral_windup = True
 #   Simulation parameters
 simulate = True
 sim_t_env      = 60.0   # deg C
-sim_c_heat     = 100.0  # J/K  heat capacity of heat element
+sim_c_heat     = 500.0  # J/K  heat capacity of heat element
 sim_c_oven     = 5000.0 # J/K  heat capacity of oven
 sim_p_heat     = 5450.0 # W    heating power of oven
-sim_R_o_nocool = 0.1   # K/W  thermal resistance oven -> environment
+sim_R_o_nocool = 0.5   # K/W  thermal resistance oven -> environment
 sim_R_o_cool   = 0.05   # K/W  " with cooling
 sim_R_ho_noair = 0.1    # K/W  thermal resistance heat element -> oven
 sim_R_ho_air   = 0.05   # K/W  " with internal air circulation
@@ -121,7 +121,7 @@ kiln_must_catch_up = True
 # or 100% off because the kiln is too hot. No integral builds up
 # outside the window. The bigger you make the window, the more
 # integral you will accumulate.
-pid_control_window = 10 #degrees 
+pid_control_window = 5 #degrees 
 
 # thermocouple offset
 # If you put your thermocouple in ice water and it reads 36F, you can
@@ -151,3 +151,15 @@ ac_freq_50hz = False
 # - too many errors in a short period from thermocouple
 # and some people just want to ignore all of that and just log the emergencies but do not quit
 ignore_emergencies = False
+
+########################################################################
+# automatic restarts - if you have a power brown-out and the raspberry pi
+# reboots, this restarts your kiln where it left off in the firing profile.
+# This only happens if power comes back before automatic_restart_window
+# is exceeded (in minutes). The kiln-controller.py process must start
+# automatically on boot-up for this to work.
+automatic_restarts = True
+automatic_restart_window = 15 # max minutes since power outage
+automatic_restart_state_file = "/tmp/kiln_controller_state.json"
+
+

kiln-controller.py

@@ -42,6 +42,8 @@ else:
     log.info("this is a real kiln")
     oven = RealOven()
 ovenWatcher = OvenWatcher(oven)
+# this ovenwatcher is used in the oven class for restarts
+oven.set_ovenwatcher(ovenWatcher)
 
 @app.route('/')
 def index():

lib/oven.py

@@ -5,6 +5,7 @@ import datetime
 import logging
 import json
 import config
+import os
 
 log = logging.getLogger(__name__)
 
@@ -290,9 +291,72 @@ class Oven(threading.Thread):
         }
         return state
 
+    def save_state(self):
+        with open(config.automatic_restart_state_file, 'w', encoding='utf-8') as f:
+            json.dump(self.get_state(), f, ensure_ascii=False, indent=4)
+
+    def state_file_is_old(self):
+        '''returns True is state files is older than 15 mins default
+                   False if younger
+                   True if state file cannot be opened or does not exist
+        '''
+        if os.path.isfile(config.automatic_restart_state_file):
+            state_age = os.path.getmtime(config.automatic_restart_state_file)
+            now = time.time()
+            if((now - state_age)/60 <= config.automatic_restart_window):
+                return False
+        return True
+
+
+    def automatic_restart(self):
+        '''takes one of two actions
+        if RUNNING, saves state every duty cycle
+        if IDLE, checks and then starts last known good profile where it died
+        '''
+        # check if automatic_restart setting is True
+        if not config.automatic_restarts == True:
+            return
+
+        if self.state == "RUNNING":
+            # save state every duty cycle (2s by default)
+            self.save_state()
+            return
+
+        # check if within window (use file timestamp and setting)
+        if self.state_file_is_old():
+            log.info("restart not possible. outside restart window")
+            return
+
+        # restart the last known profile where it died
+        self.restart()
+
+    def restart(self):
+        if os.path.isfile(config.automatic_restart_state_file):
+            with open(config.automatic_restart_state_file) as infile: d = json.load(infile)
+        else:
+            log.info("restart not possible. no state file found.")
+            return
+        # check if last profile finished
+        if d["totaltime"] - d["runtime"] > 60:
+            startat = d["runtime"]/60
+            filename = "%s.json" % (d["profile"])
+            profile_path = os.path.abspath(os.path.join(os.path.dirname( __file__ ), '..', 'storage','profiles',filename))
+
+            log.info("restarting profile = %s at minute = %d" % (profile_path,startat))
+            with open(profile_path) as infile:
+                profile_json = json.dumps(json.load(infile))
+            profile = Profile(profile_json)
+            self.run_profile(profile,startat=startat)
+            self.ovenwatcher.record(profile)
+
+
+    def set_ovenwatcher(self,watcher):
+        self.ovenwatcher = watcher
+
     def run(self):
         while True:
             if self.state == "IDLE":
+                self.automatic_restart()
                 time.sleep(1)
                 continue
             if self.state == "RUNNING":
@@ -302,7 +366,7 @@ class Oven(threading.Thread):
                 self.heat_then_cool()
                 self.reset_if_emergency()
                 self.reset_if_schedule_ended()
-
+                self.automatic_restart()
 
 class SimulatedOven(Oven):