Merge pull request #72 from petermcd/example-fixes
[EVA-2020-02-2.git] / examples / weather-and-light.py
index fde1d9610ee31c031e1c294ec1043859bc797b53..bccf7cc0d69cf09947389ff01607706346e45046 100755 (executable)
@@ -12,6 +12,7 @@ from bme280 import BME280
 from ltr559 import LTR559
 
 import pytz
+from pytz import timezone
 from astral.geocoder import database, lookup
 from astral.sun import sun
 from datetime import datetime, timedelta
@@ -79,19 +80,21 @@ def x_from_sun_moon_time(progress, period, x_range):
     return x
 
 
-def sun_moon_time(dt, city_name, time_zone):
+def sun_moon_time(city_name, time_zone):
     """Calculate the progress through the current sun/moon period (i.e day or
        night) from the last sunrise or sunset, given a datetime object 't'."""
 
     city = lookup(city_name, database())
 
     # Datetime objects for yesterday, today, tomorrow
-    today = dt.date()
-    dt = pytz.timezone(time_zone).localize(dt)
+    utc = pytz.utc
+    utc_dt = datetime.now(tz=utc)
+    local_dt = utc_dt.astimezone(pytz.timezone(time_zone))
+    today = local_dt.date()
     yesterday = today - timedelta(1)
     tomorrow = today + timedelta(1)
 
-    # Sun objects for yesterfay, today, tomorrow
+    # Sun objects for yesterday, today, tomorrow
     sun_yesterday = sun(city.observer, date=yesterday)
     sun_today = sun(city.observer, date=today)
     sun_tomorrow = sun(city.observer, date=tomorrow)
@@ -103,29 +106,29 @@ def sun_moon_time(dt, city_name, time_zone):
     sunrise_tomorrow = sun_tomorrow["sunrise"]
 
     # Work out lengths of day or night period and progress through period
-    if sunrise_today < dt < sunset_today:
+    if sunrise_today < local_dt < sunset_today:
         day = True
         period = sunset_today - sunrise_today
-        mid = sunrise_today + (period / 2)
-        progress = dt - sunrise_today
+        mid = sunrise_today + (period / 2)
+        progress = local_dt - sunrise_today
 
-    elif dt > sunset_today:
+    elif local_dt > sunset_today:
         day = False
         period = sunrise_tomorrow - sunset_today
-        mid = sunset_today + (period / 2)
-        progress = dt - sunset_today
+        mid = sunset_today + (period / 2)
+        progress = local_dt - sunset_today
 
     else:
         day = False
         period = sunrise_today - sunset_yesterday
-        mid = sunset_yesterday + (period / 2)
-        progress = dt - sunset_yesterday
+        mid = sunset_yesterday + (period / 2)
+        progress = local_dt - sunset_yesterday
 
     # Convert time deltas to seconds
     progress = progress.total_seconds()
     period = period.total_seconds()
 
-    return (progress, period, day)
+    return (progress, period, day, local_dt)
 
 
 def draw_background(progress, period, day):
@@ -139,7 +142,7 @@ def draw_background(progress, period, day):
     if day:
         x = WIDTH - x
 
-    # Calculate position on sun/moon's curve
+    # Calculate position on sun/moon's curve
     centre = WIDTH / 2
     y = calculate_y_pos(x, centre)
 
@@ -148,7 +151,7 @@ def draw_background(progress, period, day):
 
     # New image for background colour
     img = Image.new('RGBA', (WIDTH, HEIGHT), color=background)
-    draw = ImageDraw.Draw(img)
+    draw = ImageDraw.Draw(img)
 
     # New image for sun/moon overlay
     overlay = Image.new('RGBA', (WIDTH, HEIGHT), color=(0, 0, 0, 0))
@@ -213,12 +216,12 @@ def analyse_pressure(pressure, t):
         slope = line[0][0]
         intercept = line[0][1]
         variance = numpy.var(pressure_vals)
-        residuals = numpy.var([(slope * x + intercept - y)  for x, y in zip(time_vals, pressure_vals)])
+        residuals = numpy.var([(slope * x + intercept - y) for x, y in zip(time_vals, pressure_vals)])
         r_squared = 1 - residuals / variance
 
         # Calculate change in pressure per hour
         change_per_hour = slope * 60 * 60
-        variance_per_hour = variance * 60 * 60
+        variance_per_hour = variance * 60 * 60
 
         mean_pressure = numpy.mean(pressure_vals)
 
@@ -241,10 +244,10 @@ def analyse_pressure(pressure, t):
         change_per_hour = 0
         trend = "-"
 
-#    time.sleep(interval)
-
+    # time.sleep(interval)
     return (mean_pressure, change_per_hour, trend)
 
+
 def describe_pressure(pressure):
     """Convert pressure into barometer-type description."""
     if pressure < 970:
@@ -319,7 +322,6 @@ font_lg = ImageFont.truetype(UserFont, 14)
 # Margins
 margin = 3
 
-dt = datetime.now()
 
 # Set up BME280 weather sensor
 bus = SMBus(1)
@@ -346,14 +348,13 @@ start_time = time.time()
 
 while True:
     path = os.path.dirname(os.path.realpath(__file__))
-    dt = datetime.now()
-    progress, period, day = sun_moon_time(dt, city_name, time_zone)
+    progress, period, day, local_dt = sun_moon_time(city_name, time_zone)
     background = draw_background(progress, period, day)
 
     # Time.
     time_elapsed = time.time() - start_time
-    date_string = dt.strftime("%d %b %y").lstrip('0')
-    time_string = dt.strftime("%H:%M")
+    date_string = local_dt.strftime("%d %b %y").lstrip('0')
+    time_string = local_dt.strftime("%H:%M")
     img = overlay_text(background, (0 + margin, 0 + margin), time_string, font_lg)
     img = overlay_text(img, (WIDTH - margin, 0 + margin), date_string, font_lg, align_right=True)
 
@@ -384,7 +385,7 @@ while True:
     else:
         range_string = "------"
     img = overlay_text(img, (68, 18 + spacing), range_string, font_sm, align_right=True, rectangle=True)
-    temp_icon = Image.open(path + "/icons/temperature.png")
+    temp_icon = Image.open(f"{path}/icons/temperature.png")
     img.paste(temp_icon, (margin, 18), mask=temp_icon)
 
     # Humidity
@@ -395,7 +396,7 @@ while True:
     spacing = font_lg.getsize(humidity_string)[1] + 1
     humidity_desc = describe_humidity(corr_humidity).upper()
     img = overlay_text(img, (68, 48 + spacing), humidity_desc, font_sm, align_right=True, rectangle=True)
-    humidity_icon = Image.open(path + "/icons/humidity-" + humidity_desc.lower() + ".png")
+    humidity_icon = Image.open(f"{path}/icons/humidity-{humidity_desc.lower()}.png")
     img.paste(humidity_icon, (margin, 48), mask=humidity_icon)
 
     # Light
@@ -405,7 +406,7 @@ while True:
     spacing = font_lg.getsize(light_string.replace(",", ""))[1] + 1
     light_desc = describe_light(light).upper()
     img = overlay_text(img, (WIDTH - margin - 1, 18 + spacing), light_desc, font_sm, align_right=True, rectangle=True)
-    light_icon = Image.open(path + "/icons/bulb-" + light_desc.lower() +  ".png")
+    light_icon = Image.open(f"{path}/icons/bulb-{light_desc.lower()}.png")
     img.paste(humidity_icon, (80, 18), mask=light_icon)
 
     # Pressure
@@ -417,7 +418,7 @@ while True:
     pressure_desc = describe_pressure(mean_pressure).upper()
     spacing = font_lg.getsize(pressure_string.replace(",", ""))[1] + 1
     img = overlay_text(img, (WIDTH - margin - 1, 48 + spacing), pressure_desc, font_sm, align_right=True, rectangle=True)
-    pressure_icon = Image.open(path + "/icons/weather-" + pressure_desc.lower() +  ".png")
+    pressure_icon = Image.open(f"{path}/icons/weather-{pressure_desc.lower()}.png")
     img.paste(pressure_icon, (80, 48), mask=pressure_icon)
 
     # Display image