From 6bc9847a518848a2f0050126c649b25f59a1a860 Mon Sep 17 00:00:00 2001
From: Andrew de Quincey <adq@lidskialf.net>
Date: Mon, 19 Apr 2021 21:42:33 +0100
Subject: [PATCH] Add kiln-display

---
 kiln-display.py | 137 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 137 insertions(+)
 create mode 100644 kiln-display.py

diff --git a/kiln-display.py b/kiln-display.py
new file mode 100644
index 0000000..3ca26be
--- /dev/null
+++ b/kiln-display.py
@@ -0,0 +1,137 @@
+#!/usr/bin/env python
+
+import websocket
+import json
+import time
+import datetime
+import digitalio
+import board
+import adafruit_rgb_display.st7789 as st7789
+from PIL import Image, ImageDraw, ImageFont
+
+
+KILN_HOSTNAME = 'localhost:8081'
+MIN_UPDATE_SECS = 10
+
+status_ws = websocket.WebSocket()
+storage_ws = websocket.WebSocket()
+
+# 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("/home/adq/DroidSans.ttf", 46)
+chartminx = 0
+chartw = display.width
+chartminy = int(display.height / 2)
+charth = int(display.height / 2)
+
+# main loop
+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://{KILN_HOSTNAME}/status')
+            storage_ws.connect(f'ws://{KILN_HOSTNAME}/storage')
+        except Exception:
+            time.sleep(5)
+
+        continue
+
+    # we don't need to update ALL the time
+    if (datetime.datetime.now() - last_update).total_seconds() < MIN_UPDATE_SECS:
+        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='yellow')
+
+    # inform if we're actively heating
+    if msg.get('heat'):
+        screend.ellipse((display.width - 25, display.height - 25, display.width - 5, display.height - 5), 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')
+
+        # show the 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)