Emergency shutoff

config.py

@@ -1,7 +1,7 @@
 import logging
 
 # uncomment this if using MAX-31856
-#from lib.max31856 import MAX31856
+from lib.max31856 import MAX31856
 
 ########################################################################
 #
@@ -10,6 +10,8 @@
 ### Logging
 log_level = logging.INFO
 log_format = '%(asctime)s %(levelname)s %(name)s: %(message)s'
+log_file = '/home/pi/kiln-controller.log'
+status_file = '/home/pi/kiln-controller.status'
 
 ### Server
 listening_ip = "0.0.0.0"
@@ -29,22 +31,51 @@
 #   can use whichever GPIO you prefer/have available.
 
 ### Outputs
-gpio_heat = 23  # Switches zero-cross solid-state-relay
+
+## Mosfet outputs
+gpio_heat = 17  # pin 11 Switches zero-cross solid-state-relay
+gpio_e_relay = 27 # pin 13
+gpio_fan = 22 # pin 15
+
+#   Note: `gpio_e_relay` is used to and a redundant mechanical relay in series with
+#   the SSR. Because SSRs normally fail closed (i.e. energized), this provides a 
+#   way for the controller to shut off the kiln in the event that the SSR fails.
+#   It is designed to be used with the SSR input connected to the safety relay's
+#   Normally Open (NC) output; thus, the kiln can only heat when the RPi has
+#   energized the safety relay. 
+
+## Display outputs
+
+temp_disp = {'type': 'TMC1637',
+             'pins': {'clock': 16,
+                      'data': 26}} # pin 36, pin 37
+
+time_disp = {'type': 'TMC1637',
+             'pins': {'clock': 20,
+                      'data': 21}}  # pin 38, pin 40
+
+gpio_dotstar_clk = 19 # pin 35
+gpio_dotstar_dat = 13 # pin 33
+
+## I2C pins
+gpio_i2c_sda1 = 2 # pin 3
+gpio_i2c_scl1 = 3 # pin 5
+
 
 ### Thermocouple Adapter selection:
 #   max31855 - bitbang SPI interface
 #   max31856 - bitbang SPI interface. must specify thermocouple_type.
-max31855 = 1
-max31856 = 0
+max31855 = 0
+max31856 = 1
 # see lib/max31856.py for other thermocouple_type, only applies to max31856
 # uncomment this if using MAX-31856
-#thermocouple_type = MAX31856.MAX31856_S_TYPE
+thermocouple_type = MAX31856.MAX31856_K_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
+gpio_sensor_cs = 8  # pin 24
+gpio_sensor_clock = 11  # pin 23
+gpio_sensor_data = 9  # pin 21
+gpio_sensor_di = 10 # pin 19
 
 ########################################################################
 #
@@ -83,7 +114,7 @@
 ########################################################################
 #
 #   Simulation parameters
-simulate = True
+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

dotstar_fail.py

@@ -0,0 +1,31 @@
+# SPDX-FileCopyrightText: 2021 Kattni Rembor for Adafruit Industries
+# SPDX-License-Identifier: MIT
+
+"""
+ 5This example blinks the LEDs purple at a 0.5 second interval.
+ 6
+ 7For QT Py Haxpress and a NeoPixel strip. Update pixel_pin and pixel_num to match your wiring if
+ 8using a different board or form of NeoPixels.
+ 9
+This example will run on SAMD21 (M0) Express boards (such as Circuit Playground Express or QT Py
+Haxpress), but not on SAMD21 non-Express boards (such as QT Py or Trinket).
+"""
+import config
+import board
+import adafruit_dotstar
+
+from adafruit_led_animation.animation.blink import Blink
+from adafruit_led_animation.color import PURPLE
+
+dotstar_num = config.dotstar_num = 27
+dotstar_clk = config.gpio_dotstar_clk = 19  # pin 35
+dotstar_dat = config.gpio_dotstar_dat = 13  # pin 33
+
+pixels = adafruit_dotstar.DotStar(getattr(board, 'D%s' % dotstar_clk),
+                                  getattr(board, 'D%s' % dotstar_dat),
+                                  dotstar_num)
+
+blink = Blink(pixels, speed=0.5, color=PURPLE)
+
+while True:
+    blink.animate()

dotstar_watcher.py

@@ -0,0 +1,143 @@
+#!/usr/bin/env python
+
+import board
+import adafruit_dotstar
+import config
+import ast
+from time import sleep
+from math import ceil
+from adafruit_led_animation.helper import PixelSubset
+from adafruit_led_animation.animation.rainbowchase import RainbowChase
+from adafruit_led_animation.animation.pulse import Pulse
+from adafruit_led_animation.animation.comet import Comet
+from adafruit_led_animation.animation.blink import Blink
+from adafruit_led_animation.color import PURPLE
+from adafruit_led_animation.group import AnimationGroup
+from adafruit_led_animation.sequence import AnimationSequence
+
+
+time_int = 0.5
+
+
+class KilnStatus:
+    def __init__(self, status_fp):
+        self.state = 'STARTUP'
+        self.heat = False
+        self.temp = 0.0
+        self.target = 0.0
+        self.runtime = 0.0
+        self.totaltime = 0.0
+        self.delay = 0.5
+        self.status_fp = status_fp
+        self.speed = 0.1
+
+    def check_status(self):
+        with open(self.status_fp, 'r') as f:
+            status = ast.literal_eval(f.readline().strip())
+        self.state = status['state']
+        self.heat = status['heat']
+        self.temp = status['temperature']
+        self.target = status['target']
+        self.totaltime = status['totaltime']
+        self.runtime = status['runtime']
+
+# {'runtime': 0,
+#  'temperature': 78.41890624999999,
+#  'target': 0,
+#  'state': 'IDLE',
+#  'heat': 0,
+#  'totaltime': 0,
+#  'kwh_rate': 0.1319,
+#  'currency_type': '$',
+#  'profile': None,
+#  'pidstats': {}}
+
+
+def update_status(kiln_status):
+    """Monitor button that reverses rainbow direction and changes blink speed.
+    Assume button is active low.
+    """
+
+    kiln_status.check_status()
+
+
+def task_strip_top(pixels, kiln_status):
+    while True:
+        if kiln_status.state == 'STARTUP':
+            top = RainbowChase(pixels,
+                               kiln_status.speed,
+                               size=2,
+                               spacing=3,
+                               reverse=False,
+                               step=8)
+        elif kiln_status.state == 'IDLE':
+            top = Pulse(pixels,
+                        kiln_status.speed,
+                        (135, 135, 135),
+                        period=5)
+        elif kiln_status.state == 'RUNNING':
+            top = Comet(pixels,
+                        kiln_status.speed,
+                        (120, 200, 180),
+                        tail_length=10,
+                        reverse=False,
+                        bounce=False,
+                        ring=True)
+        elif kiln_status.state == 'EMERGENCY RESET':
+            top = Blink(pixels,
+                        0.7,
+                        (255, 0, 0))
+    return(top)
+
+def task_strip_right(pixels, kiln_status):
+    r_blink = Blink(pixels, speed=0.5, color=PURPLE)
+    return(r_blink)
+
+def main():
+
+    # setup
+
+    status_fp = config.status_file
+
+    kiln_status = KilnStatus(status_fp)
+
+    dotstar_num = config.dotstar_num = 27
+    dotstar_clk = config.gpio_dotstar_clk = 19  # pin 35
+    dotstar_dat = config.gpio_dotstar_dat = 13  # pin 33
+
+    pixels = adafruit_dotstar.DotStar(getattr(board, 'D%s' % dotstar_clk),
+                                      getattr(board, 'D%s' % dotstar_dat),
+                                      dotstar_num)
+
+    substrip_len = ceil(dotstar_num/3.0)
+
+    strip_left = PixelSubset(pixels,
+                             0,
+                             substrip_len)
+
+    strip_right = PixelSubset(pixels,
+                              dotstar_num - substrip_len,
+                              dotstar_num)
+
+    strip_top = PixelSubset(pixels,
+                            substrip_len,
+                            dotstar_num - substrip_len)
+
+    l_blink = Blink(strip_left, speed=0.5, color=PURPLE)
+
+
+    while True:
+        kiln_status.check_status()
+        right = task_strip_right(strip_right, kiln_status)
+        top = task_strip_top(strip_top, kiln_status)
+        animations = AnimationSequence(
+                AnimationGroup(
+                    l_blink,
+                    right,
+                    top
+                ))
+        animations.animate()
+        sleep(time_int)
+
+if __name__ == "__main__":
+    main()

gpio_off.py

@@ -0,0 +1,5 @@
+#!/usr/bin/env python
+
+if __name__ == "__main__":
+    pins = list(range(0,40))
+        GPIO.setup(pins, GPIO.IN, pull_up_down=GPIO.PUD_DOWN)

kiln-controller.py

@@ -23,7 +23,9 @@
     print ("Copy config.py.EXAMPLE to config.py and adapt it for your setup.")
     exit(1)
 
-logging.basicConfig(level=config.log_level, format=config.log_format)
+logging.basicConfig(level=config.log_level,
+                    format=config.log_format,
+                    filename=config.log_file)
 log = logging.getLogger("kiln-controller")
 log.info("Starting kiln controller")
 

lib/display.py

@@ -0,0 +1,35 @@
+import tm1637
+import logging
+
+log = logging.getLogger(__name__)
+
+
+class TM1637(object):
+    def __init__(self,
+                 clk_pin,
+                 dat_pin):
+
+        self.clk_pin = clk_pin
+        self.dat_pin = dat_pin
+
+        try:
+            self.tm = tm1637.TM1637(clk=clk_pin,
+                                    dio=dat_pin)
+        except ImportError as e:
+            log.warning('import failure: \n%s' % e)
+
+    def temp(self,
+             t):
+        self.tm.number(t)
+
+    def time(self,
+             h,
+             m):
+        self.tm.numbers(h, m, True)
+
+    def text(self,
+             text):
+        self.tm.show(text[0:4])
+
+    def off(self):
+        self.tm.write([0, 0, 0, 0])

lib/init/kiln-controller.service

@@ -3,6 +3,7 @@ Description=kiln-controller
 
 [Service]
 ExecStart=/home/pi/kiln-controller/venv/bin/python /home/pi/kiln-controller/kiln-controller.py
+ExecStopPost=/home/pi/kiln-controller/venv/bin/python /home/pi/kiln-controller/gpio_off.py
 
 [Install]
 WantedBy=multi-user.target

lib/init/kiln-display.service

@@ -0,0 +1,9 @@
+[Unit]
+Description=kiln-display
+
+[Service]
+ExecStart=/home/pi/kiln-controller/venv/bin/python /home/pi/kiln-controller/dotstar_watcher.py
+ExecStopPost=/home/pi/kiln-controller/venv/bin/python /home/pi/kiln-controller/dotstar_fail.py
+
+[Install]
+WantedBy=multi-user.target