add recorder code

kiln-tuner.py

@@ -0,0 +1,83 @@
+import os
+import sys
+import csv
+import time
+import argparse
+
+
+try:
+    sys.dont_write_bytecode = True
+    import config
+    sys.dont_write_bytecode = False
+
+except:
+    print("Could not import config file.")
+    print("Copy config.py.EXAMPLE to config.py and adapt it for your setup.")
+    exit(1)
+
+script_dir = os.path.dirname(os.path.realpath(__file__))
+sys.path.insert(0, script_dir + '/lib/')
+profile_path = os.path.join(script_dir, "storage", "profiles")
+
+from oven import RealOven, SimulatedOven
+
+
+def tune(csvfile, targettemp):
+    # open the file to log data to
+    f = open(csvfile, 'w')
+    csvout = csv.writer(f)
+    csvout.write(['time', 'temperature'])
+
+    # construct the oven
+    if config.simulate:
+        oven = SimulatedOven()
+    else:
+        oven = RealOven()
+
+    # Main loop:
+    #
+    # * heat the oven to the target temperature at maximum burn.
+    # * when we reach it turn the heating off completely.
+    # * wait for it to decay back to the target again.
+    # * quit
+    #
+    # We record the temperature every config.sensor_time_wait
+    try:
+        stage = 'heating'
+        if not config.simulate:
+            oven.output.heat(1, tuning=True)
+
+        while True:
+            temp = oven.board.temp_sensor.temperature + \
+                config.thermocouple_offset
+
+            csvout.writerow([time.time(), temp])
+            csvout.flush()
+
+            if stage == 'heating':
+                if temp > targettemp:
+                    if not config.simulate:
+                        oven.output.heat(0)
+                    stage = 'decaying'
+
+            elif stage == 'decaying':
+                if temp < targettemp:
+                    break
+
+            time.sleep(config.sensor_time_wait)
+
+        f.close()
+
+    finally:
+        # ensure we always shut the oven down!
+        if not config.simulate:
+            oven.output.heat(0)
+
+
+if __name__ == "__main__":
+    parser = argparse.ArgumentParser(description='Record data for kiln tuning')
+    parser.add_argument('csvfile', type=str, help="The CSV file to write to.")
+    parser.add_argument('--targettemp', type='int', default=400, help="The target temperature to drive the kiln to.")
+    args = parser.parse_args()
+
+    tune(args.csvfile, args.targettemp)

lib/oven.py

@@ -26,8 +26,10 @@ class Output(object):
             log.warning(msg)
             self.active = False
 
-    def heat(self,sleepfor):
+    def heat(self,sleepfor, tuning=False):
         self.GPIO.output(config.gpio_heat, self.GPIO.HIGH)
+        if tuning:
+            return
         time.sleep(sleepfor)
         self.GPIO.output(config.gpio_heat, self.GPIO.LOW)
 
@@ -54,7 +56,7 @@ class Board(object):
                 self.active = True
                 log.info("import %s " % (self.name))
             except ImportError:
-                msg = "max31855 config set, but import failed" 
+                msg = "max31855 config set, but import failed"
                 log.warning(msg)
 
         if config.max31856:
@@ -64,7 +66,7 @@ class Board(object):
                 self.active = True
                 log.info("import %s " % (self.name))
             except ImportError:
-                msg = "max31856 config set, but import failed" 
+                msg = "max31856 config set, but import failed"
                 log.warning(msg)
 
     def create_temp_sensor(self):
@@ -76,7 +78,7 @@ class Board(object):
 class BoardSimulated(object):
     def __init__(self):
         self.temp_sensor = TempSensorSimulated()
- 
+
 class TempSensor(threading.Thread):
     def __init__(self):
         threading.Thread.__init__(self)
@@ -118,7 +120,7 @@ class TempSensorReal(TempSensor):
         '''take 5 measurements over each time period and return the
         average'''
         while True:
-            maxtries = 5 
+            maxtries = 5
             sleeptime = self.time_step / float(maxtries)
             temps = []
             for x in range(0,maxtries):
@@ -245,10 +247,10 @@ class SimulatedOven(Oven):
         # set temps to the temp of the surrounding environment
         self.t = self.t_env # deg C temp of oven
         self.t_h = self.t_env #deg C temp of heating element
-        
+
         # call parent init
         Oven.__init__(self)
-        
+
         # start thread
         self.start()
         log.info("SimulatedOven started")
@@ -306,9 +308,9 @@ class SimulatedOven(Oven):
              self.runtime,
              self.totaltime,
              time_left))
-        
+
         # we don't actually spend time heating & cooling during
-        # a simulation, so sleep. 
+        # a simulation, so sleep.
         time.sleep(self.time_step)
 
 
@@ -396,7 +398,7 @@ class PID():
         self.lastErr = 0
 
     # FIX - this was using a really small window where the PID control
-    # takes effect from -1 to 1. I changed this to various numbers and 
+    # takes effect from -1 to 1. I changed this to various numbers and
     # settled on -50 to 50 and then divide by 50 at the end. This results
     # in a larger PID control window and much more accurate control...
     # instead of what used to be binary on/off control.
@@ -410,7 +412,7 @@ class PID():
 
         if self.ki > 0:
             self.iterm += (error * timeDelta * (1/self.ki))
-        
+
         dErr = (error - self.lastErr) / timeDelta
         output = self.kp * error + self.iterm + self.kd * dErr
         out4logs = output
@@ -427,10 +429,10 @@ class PID():
 
         output = float(output / window_size)
 
-        if out4logs > 0:        
+        if out4logs > 0:
             log.info("pid percents pid=%0.2f p=%0.2f i=%0.2f d=%0.2f" % (out4logs,
-                ((self.kp * error)/out4logs)*100, 
+                ((self.kp * error)/out4logs)*100,
                 (self.iterm/out4logs)*100,
-                ((self.kd * dErr)/out4logs)*100)) 
+                ((self.kd * dErr)/out4logs)*100))
 
         return output

zieglernicols.py

@@ -2,7 +2,8 @@ import csv
 import argparse
 
 
-# Using the method from https://www.ias.ac.in/article/fulltext/reso/025/10/1385-1397 or https://www.youtube.com/watch?v=nvAQHSe-Ax4
+# Using the method described in "Ziegler–Nichols Tuning Method∗" by Vishakha Vijay Patel
+# (https://www.ias.ac.in/article/fulltext/reso/025/10/1385-1397)
 
 
 def line(a, b, x):