updating example config file

config.py.EXAMPLE

@@ -1,4 +1,5 @@
 import logging
+from lib.max31856 import MAX31856
 
 ########################################################################
 #
@@ -13,7 +14,7 @@ listening_ip = "0.0.0.0"
 listening_port = 8081
 
 ### Cost Estimate
-kwh_rate        = 0.18  # Rate in currency_type to calculate cost to run job
+kwh_rate        = 0.1319  # Rate in currency_type to calculate cost to run job
 currency_type   = "$"   # Currency Symbol to show when calculating cost to run job
 
 ########################################################################
@@ -27,45 +28,66 @@ currency_type   = "$"   # Currency Symbol to show when calculating cost to run j
 
 ### Outputs
 gpio_heat = 23  # Switches zero-cross solid-state-relay
-heater_invert = 0 # switches the polarity of the heater control
 
 ### Thermocouple Adapter selection:
 #   max31855 - bitbang SPI interface
-#   max31855spi - kernel SPI interface
-#   max6675 - bitbang SPI interface
+#   max31856 - bitbang SPI interface. must specify thermocouple_type.
 max31855 = 1
-max6675 = 0
-max31855spi = 0 # if you use this one, you MUST reassign the default GPIO pins
+max31856 = 0
+# see lib/max31856.py for other thermocouple_type, only applies to max31856
+thermocouple_type = MAX31856.MAX31856_S_TYPE
 
 ### Thermocouple Connection (using bitbang interfaces)
 gpio_sensor_cs = 27
 gpio_sensor_clock = 22
 gpio_sensor_data = 17
+gpio_sensor_di = 10 # only used with max31856
 
-### Thermocouple SPI Connection (using adafrut drivers + kernel SPI interface)
-spi_sensor_chip_id = 0
-
-### duty cycle of the entire system in seconds. Every N seconds a decision
-### is made about switching the relay[s] on & off and for how long.
-### The thermocouple is read five times during this period and the highest
-### value is used.
+########################################################################
+#
+# duty cycle of the entire system in seconds
+# 
+# Every N seconds a decision is made about switching the relay[s] 
+# on & off and for how long. The thermocouple is read 
+# temperature_average_samples times during and the average value is used.
 sensor_time_wait = 2
 
 
 ########################################################################
 #
 #   PID parameters
+#
+# These parameters control kiln temperature change. These settings work
+# well with the simulated oven. You must tune them to work well with 
+# your specific kiln. Note that the integral pid_ki is
+# inverted so that a smaller number means more integral action.
 
-pid_kp = 25  # Proportional
-pid_ki = 1088  # Integration
-pid_kd = 217  # Derivative was 217
+# from experimentation
+#pid_kp = 10   # Proportional 
+#pid_ki = 50  # Integral
+#pid_kd = 100  # Derivative
 
+# from ZN tuning
+pid_kp = 3.0662264423638184
+pid_ki = 61.295706065671204
+pid_kd = 144.07164331295013
+
+########################################################################
+#
+# Initial heating and Integral Windup
+#
+# During initial heating, if the temperature is constantly under the
+# setpoint,large amounts of Integral can accumulate. This accumulation
+# causes the kiln to run above the setpoint for potentially a long
+# period of time. These settings allow integral accumulation only when
+# the temperature is close to the setpoint. This applies only to the integral.
+stop_integral_windup = True
 
 ########################################################################
 #
 #   Simulation parameters
-
-sim_t_env      = 25.0   # deg C
+simulate = False
+sim_t_env      = 60.0   # deg C
 sim_c_heat     = 100.0  # 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
@@ -78,27 +100,46 @@ sim_R_ho_air   = 0.05   # K/W  " with internal air circulation
 ########################################################################
 #
 #   Time and Temperature parameters
+#
+# If you change the temp_scale, all settings in this file are assumed to
+# be in that scale.
 
-temp_scale          = "f" # c = Celsius | f = Fahrenheit - Unit to display 
+temp_scale          = "f" # c = Celsius | f = Fahrenheit - Unit to display
 time_scale_slope    = "h" # s = Seconds | m = Minutes | h = Hours - Slope displayed in temp_scale per time_scale_slope
 time_scale_profile  = "m" # s = Seconds | m = Minutes | h = Hours - Enter and view target time in time_scale_profile
 
-# emergency shutoff the kiln if this temp is reached.
-# when solid state relays fail, they usually fail closed.  this means your
-# kiln receives full power until your house burns down.
+# emergency shutoff the profile if this temp is reached or exceeded.
+# This just shuts off the profile. If your SSR is working, your kiln will
+# naturally cool off. If your SSR has failed/shorted/closed circuit, this
+# means your kiln receives full power until your house burns down.
 # this should not replace you watching your kiln or use of a kiln-sitter
-emergency_shutoff_temp = 2250
+emergency_shutoff_temp = 2264 #cone 7
 
-# not used yet
-# if measured value is N degrees below set point
-warning_temp_low = 5
-
-# not used yet
-# if measured value is N degrees above set point
-warning_temp_high = 5
+# If the kiln cannot heat or cool fast enough and is off by more than
+# kiln_must_catch_up_max_error  the entire schedule is shifted until
+# the desired temperature is reached. If your kiln cannot attain the
+# wanted temperature, the schedule will run forever. This is often used
+# for heating as fast as possible in a section of a kiln schedule/profile.
+kiln_must_catch_up = True
+kiln_must_catch_up_max_error = 10 #degrees
 
 # thermocouple offset
 # If you put your thermocouple in ice water and it reads 36F, you can
 # set set this offset to -4 to compensate.  This probably means you have a
 # cheap thermocouple.  Invest in a better thermocouple.
 thermocouple_offset=0
+
+# some kilns/thermocouples start erroneously reporting "short" 
+# errors at higher temperatures due to plasma forming in the kiln.
+# Set this to False to ignore these errors and assume the temperature 
+# reading was correct anyway
+honour_theromocouple_short_errors = False
+
+# number of samples of temperature to average.
+# If you suffer from the high temperature kiln issue and have set 
+# honour_theromocouple_short_errors to False,
+# you will likely need to increase this (eg I use 40)
+temperature_average_samples = 40 
+
+# Thermocouple AC frequency filtering - set to True if in a 50Hz locale, else leave at False for 60Hz locale
+ac_freq_50hz = False