Kiln display

config.py

@@ -49,6 +49,9 @@
 ### value is used.
 sensor_time_wait = 2
 
+# GPIO to use for the beeper
+gpio_beeper = 12
+
 
 ########################################################################
 #
@@ -57,7 +60,7 @@
 # These parameters 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_kp = 25   # Proportional
 pid_ki = 200  # Integral
 pid_kd = 200  # Derivative
 
@@ -66,11 +69,11 @@
 #
 # Initial heating and Integral Windup
 #
-# During initial heating, if the temperature is constantly under the 
+# 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 within stop_integral_windup_margin percent below 
+# the temperature is within stop_integral_windup_margin percent below
 # or above the setpoint. This applies only to the integral.
 stop_integral_windup = True
 stop_integral_windup_margin = 10
@@ -96,20 +99,20 @@
 # 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 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 
+# 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 = 2264 #cone 7 
+emergency_shutoff_temp = 2264 #cone 7
 
-# If the kiln cannot heat or cool fast enough and is off by more than 
+# 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 
+# the desired temperature is reached. If your kiln cannot attain the
 # wanted temperature, the schedule will run forever.
 kiln_must_catch_up = True
 kiln_must_catch_up_max_error = 10 #degrees

kiln-display.py

@@ -0,0 +1,210 @@
+#!/usr/bin/env python
+
+import websocket
+import json
+import time
+import datetime
+import argparse
+import digitalio
+import board
+import adafruit_rgb_display.st7789 as st7789
+import RPi.GPIO as GPIO
+from PIL import Image, ImageDraw, ImageFont
+import config
+
+# This is designed to drive an Adafruit Mini PiTFT 1.3" (https://www.adafruit.com/product/4484)
+#
+# You will require a copy of DroidSans.ttf in /home/pi
+#
+# As this occupies the GPIOs currently used as defaults in config.py, you'll have to rewrire your Pi.
+# Remember to update config.py with the new ones!
+#
+# Technically you do not need to install numpy, but it is very much recommended as the
+# non-numpy fallback code will consume much CPU.
+
+
+def beep(delay):
+    GPIO.output(config.gpio_beeper, GPIO.HIGH)
+    time.sleep(delay)
+    GPIO.output(config.gpio_beeper, GPIO.LOW)
+
+
+def morse(code):
+    for c in code:
+        if c == '.':
+            beep(0.25)
+
+        elif c == '-':
+            beep(0.5)
+
+        time.sleep(0.25)
+
+
+def display(hostname, minupdatesecs, font_ttf):
+    status_ws = websocket.WebSocket()
+    storage_ws = websocket.WebSocket()
+
+    # setup beeper GPIO
+    GPIO.setmode(GPIO.BCM)
+    GPIO.setwarnings(False)
+    GPIO.setup(config.gpio_beeper, GPIO.OUT)
+    GPIO.output(config.gpio_beeper, GPIO.LOW)
+
+    # Configuration for CS and DC pins for Raspberry Pi
+    cs_pin = digitalio.DigitalInOut(board.CE0)
+    dc_pin = digitalio.DigitalInOut(board.D25)
+    reset_pin = None
+    BAUDRATE = 64000000  # The pi can be very fast!
+    # Create the ST7789 display:
+    display = st7789.ST7789(
+        board.SPI(),
+        cs=cs_pin,
+        dc=dc_pin,
+        rst=reset_pin,
+        baudrate=BAUDRATE,
+        height=240, y_offset=80, rotation=180
+    )
+    display.fill()
+
+    # turn backlight on
+    backlight = digitalio.DigitalInOut(board.D22)
+    backlight.switch_to_output()
+    backlight.value = True
+
+    # create screen and font
+    screen = Image.new("RGB", (display.width, display.height), (0, 0, 0))
+    screend = ImageDraw.Draw(screen)
+    screenfont = ImageFont.truetype(font_ttf, 46)
+    chartminx = 0
+    chartw = display.width
+    chartminy = int(display.height / 2)
+    charth = int(display.height / 2)
+
+    # main loop
+    state = 'idle'
+    cur_profile = None
+    last_update = datetime.datetime.now()
+    while True:
+        # gather data from kiln controller.
+        try:
+            msg = json.loads(status_ws.recv())
+            if msg.get('profile') and not cur_profile:
+                storage_ws.send('GET')
+                for profile in json.loads(storage_ws.recv()):
+                    if profile['name'] == msg.get('profile'):
+                        cur_profile = profile
+                        break
+
+            elif not msg.get('profile'):
+                cur_profile = None
+
+        except websocket.WebSocketException:
+            try:
+                status_ws.connect(f'ws://{hostname}/status')
+                storage_ws.connect(f'ws://{hostname}/storage')
+            except Exception:
+                time.sleep(5)
+
+            continue
+
+        if state == 'idle' and cur_profile:
+            state = 'profile_tempok'
+
+        elif state != 'idle' and not cur_profile:
+            state = 'idle'
+            morse('-.-.')  # (C) Profile Complete
+
+        if state == 'profile_tempok':
+            tempdelta = abs(msg.get('temperature', 0) - msg.get('target', 0))
+            if tempdelta > 5:
+                state = 'profile_catchup'
+                morse('....')  # (H) Temp bad
+
+        elif state == 'profile_catchup':
+            tempdelta = abs(msg.get('temperature', 0) - msg.get('target', 0))
+            if tempdelta < 1:
+                state = 'profile_tempok'
+                morse('-')  # (T) Temp ok
+
+        # we don't need to update ALL the time
+        if (datetime.datetime.now() - last_update).total_seconds() < minupdatesecs:
+            continue
+        last_update = datetime.datetime.now()
+
+        # setup the basic display
+        screend.rectangle([0, 0, display.width, display.height], fill='black')
+        screend.line([chartminx, chartminy, chartminx + chartw, chartminy], fill='white')
+
+        # show the current temperature
+        if msg.get('temperature'):
+            temp = int(msg['temperature'])
+            text = f"{temp}°"
+            (tw, th) = screenfont.getsize(text)
+            screend.text((0, display.height - th), text, font=screenfont, fill='blue')
+
+        # inform if we're actively heating
+        if msg.get('heat'):
+            spot_radius = 20
+            spot_x = (display.width - spot_radius) / 2
+            spot_y = display.height - spot_radius - 5
+            screend.ellipse((spot_x, spot_y, spot_x + spot_radius, spot_y + spot_radius), fill='red')
+
+        # if we have a profile, show details of that!
+        if cur_profile:
+            cur_profile_data = cur_profile['data']
+
+            # compute ranges of data
+            mintime = min([i[0] for i in cur_profile_data])
+            maxtime = max([i[0] for i in cur_profile_data])
+            timerange = maxtime - mintime
+            mintemp = 0
+            maxtemp = max([i[1] for i in cur_profile_data])
+            temprange = maxtemp - mintemp
+
+            # draw chart of the temperature profie
+            line = []
+            for i in sorted(cur_profile_data, key=lambda x: x[0]):
+                x = chartminx + (((i[0] - mintime) * chartw) / timerange)
+                y = chartminy - (((i[1] - mintemp) * charth) / temprange)
+                line.extend([x, y])
+            screend.line(line, fill='yellow')
+
+            # draw current position as a blue line
+            cur_time = msg['runtime'] if msg['runtime'] > 0 else 0
+            cur_time_x = ((cur_time - mintime) * chartw) / timerange
+            cur_temp = int(msg['temperature'])
+            cur_temp_y = ((cur_temp - mintemp) * charth) / temprange
+            screend.line([chartminx + cur_time_x, chartminy, chartminx + cur_time_x, chartminy - charth], fill='blue')
+
+            # draw target temperature
+            target = int(msg['target'])
+            text = f"{target}°"
+            (tw, th) = screenfont.getsize(text)
+            screend.text((display.width - tw, display.height - th), text, font=screenfont, fill='yellow')
+
+            # show where we are
+            time_done = msg['runtime'] if msg['runtime'] > 0 else 0
+            time_done_mins = int((time_done / 60) % 60)
+            time_done_hours = int(time_done / 60 / 60)
+            screend.text((0, chartminy), f"{time_done_hours:02d}:{time_done_mins:02d}", font=screenfont, fill='blue')
+
+            # show how long we have left
+            time_left = msg['totaltime'] - msg['runtime']
+            time_left_mins = int((time_left / 60) % 60)
+            time_left_hours = int((time_left / 60) / 60)
+            text = f"{time_left_hours:02d}:{time_left_mins:02d}"
+            (tw, th) = screenfont.getsize(text)
+            screend.text((display.width - tw, chartminy), text, font=screenfont, fill='white')
+
+        # update display
+        display.image(screen)
+
+
+if __name__ == "__main__":
+    parser = argparse.ArgumentParser(description='Log kiln data for analysis.')
+    parser.add_argument('--hostname', type=str, default="localhost:8081", help="The kiln-controller hostname:port")
+    parser.add_argument('--minupdatesecs', type=int, default="10", help="Number of seconds between screen updates")
+    parser.add_argument('--font_ttf', type=str, default='/home/pi/DroidSans.ttf', help="Font to use for text display")
+    args = parser.parse_args()
+
+    display(args.hostname, args.minupdatesecs, args.font_ttf)

lib/init/kiln-controller.service

@@ -2,6 +2,7 @@
 Description=kiln-controller
 
 [Service]
+Nice=-20
 ExecStart=/home/pi/kiln-controller/venv/bin/python /home/pi/kiln-controller/kiln-controller.py
 
 [Install]

lib/init/kiln-display.service

@@ -0,0 +1,9 @@
+[Unit]
+Description=kiln-display
+
+[Service]
+Nice=10
+ExecStart=/home/pi/kiln-controller/venv/bin/python /home/pi/kiln-controller/kiln-display.py
+
+[Install]
+WantedBy=multi-user.target

requirements-kiln-display.txt

@@ -0,0 +1,4 @@
+websocket-client
+Pillow
+adafruit-circuitpython-rgb-display
+numpy