Add rain per hour and day results

documentation/boards/enviro-weather.md

@@ -13,11 +13,17 @@ Enviro Weather is a super slimline all in one board for keeping a (weather) eye
 |Air Pressure|`pressure`|hectopascals|hPa|`997.16`|
 |Luminance|`luminance`|lux|lx|`35`|
 |Rainfall|`rain`|millimetres|mm|`1.674`|
-|Rainfall Average|`rain_per_second`|millimetres per second|mm/s|`1.674`|
+|Rainfall Average Second|`rain_per_second`|millimetres per second|mm/s|`1.674`|
+|Rainfall Average Hour|`rain_per_hour`|millimetres per hour|mm/h|`1.674`|
+|Rainfall Today (local time)|`rain_today`|millimetres accumulated today|mm/s|`1.674`|
 |Wind Direction|`wind_direction`|angle|°|`45`|
 |Wind Speed|`wind_speed`|metres per second|m/s|`0.45`|
 |Voltage|`voltage`|volts|V|`4.035`|
 
+The rain today value is adjusted for DST in the UK by setting uk_bst = True in config.py
+For static time zone offsets (not taking account of DST), modify the utc_offset value in config.py
+The time zone offset value is ignored if uk_bst = True
+
 ## On-board devices
 
 - BME280 temperature, pressure, humidity sensor. [View datasheet](https://www.bosch-sensortec.com/media/boschsensortec/downloads/datasheets/bst-bme280-ds002.pdf)

enviro/boards/weather.py

@@ -1,4 +1,4 @@
-import time, math, os
+import time, math, os, config
 from breakout_bme280 import BreakoutBME280
 from breakout_ltr559 import BreakoutLTR559
 from machine import Pin, PWM
@@ -25,6 +25,28 @@
 rain_pin = Pin(10, Pin.IN, Pin.PULL_DOWN)
 last_rain_trigger = False
 
+def log_rain():
+  # read the current rain entries
+  rain_entries = []
+  if helpers.file_exists("rain.txt"):
+    with open("rain.txt", "r") as rainfile:
+      rain_entries = rainfile.read().split("\n")
+
+  # add new entry
+  logging.info(f"> add new rain trigger at {helpers.datetime_string()}")
+  rain_entries.append(helpers.datetime_string())
+
+  # limit number of entries to 190 - each entry is 21 bytes including
+  # newline so this keeps the total rain.txt filesize just under one
+  # filesystem block (4096 bytes)
+  if len(rain_entries) > 190:
+    logging.info("Rain log file exceeded 190 entries and was truncated")
+    rain_entries = rain_entries[-190:]
+
+  # write out adjusted rain log
+  with open("rain.txt", "w") as rainfile:
+    rainfile.write("\n".join(rain_entries))
+
 def startup(reason):
   global last_rain_trigger
   import wakeup
@@ -33,24 +55,7 @@ def startup(reason):
   rain_sensor_trigger = wakeup.get_gpio_state() & (1 << 10)
 
   if rain_sensor_trigger:
-    # read the current rain entries
-    rain_entries = []
-    if helpers.file_exists("rain.txt"):
-      with open("rain.txt", "r") as rainfile:
-        rain_entries = rainfile.read().split("\n")
-
-    # add new entry
-    logging.info(f"> add new rain trigger at {helpers.datetime_string()}")
-    rain_entries.append(helpers.datetime_string())
-
-    # limit number of entries to 190 - each entry is 21 bytes including
-    # newline so this keeps the total rain.txt filesize just under one
-    # filesystem block (4096 bytes)
-    rain_entries = rain_entries[-190:]
-
-    # write out adjusted rain log
-    with open("rain.txt", "w") as rainfile:
-      rainfile.write("\n".join(rain_entries))
+    log_rain()
 
     last_rain_trigger = True
 
@@ -70,24 +75,7 @@ def check_trigger():
     time.sleep(0.05)
     activity_led(0)
 
-    # read the current rain entries
-    rain_entries = []
-    if helpers.file_exists("rain.txt"):
-      with open("rain.txt", "r") as rainfile:
-        rain_entries = rainfile.read().split("\n")
-
-    # add new entry
-    logging.info(f"> add new rain trigger at {helpers.datetime_string()}")
-    rain_entries.append(helpers.datetime_string())
-
-    # limit number of entries to 190 - each entry is 21 bytes including
-    # newline so this keeps the total rain.txt filesize just under one 
-    # filesystem block (4096 bytes)
-    rain_entries = rain_entries[-190:]
-
-    # write out adjusted rain log
-    with open("rain.txt", "w") as rainfile:
-      rainfile.write("\n".join(rain_entries))
+    log_rain()
 
   last_rain_trigger = rain_sensor_trigger
 
@@ -159,26 +147,65 @@ def wind_direction():
   return closest_index * 45
 
 def rainfall(seconds_since_last):
-  amount = 0
+  new_rain_entries = []
+  amount = 0 # rain since last reading
+  per_hour = 0
+  today = 0
+  offset = 0 # UTC offset hours
+
+  # configure offset variable for UK BST or timezone offset from config file
+  # and BST lookup function
+  if config.uk_bst == True:
+    if helpers.uk_bst():
+      offset = 1
+  elif config.utc_offset != 0:
+    offset += config.utc_offset
+
+  # determine current day number and timestamp
   now = helpers.timestamp(helpers.datetime_string())
+  now_day = helpers.timestamp_day(helpers.datetime_string(), offset)
+  logging.info(f"> current day number is {now_day}")
+
+  # process the rain file data
   if helpers.file_exists("rain.txt"):
     with open("rain.txt", "r") as rainfile:
       rain_entries = rainfile.read().split("\n")
 
-    # count how many rain ticks since the last reading
+    # populate latest, per second, today and last hour readings from rain log
+    # file, write new rain log file dropping any yesterday readings
     for entry in rain_entries:
       if entry:
         ts = helpers.timestamp(entry)
+        tsday = helpers.timestamp_day(entry, config.utc_offset)
+        logging.info(f"> rain reading day number is {tsday}")
+        # populate amount with rain since the last reading
         if now - ts < seconds_since_last:
           amount += RAIN_MM_PER_TICK
-
-    os.remove("rain.txt")
+          # add any rain ticks from yesterday since the previous reading
+          # this will misallocate day totals, but will ensure the hourly total
+          # is correct without introducing complexity backdating yesterday and
+          # the error will be minimised with frequent readings
+          # TODO sum yesterday rain and generate a rain_today reading with
+          # 23:59:59 timestamp of yesterday
+          if tsday != now_day:
+            today += RAIN_MM_PER_TICK
+        # count how many rain ticks in the last hour
+        if now - ts < 3600:
+          per_hour += RAIN_MM_PER_TICK
+        # count how many rain ticks today and drop older entries for new file
+        if tsday == now_day:
+          today += RAIN_MM_PER_TICK
+          new_rain_entries.append(entry)
+
+    # write out new adjusted rain log
+    with open("rain.txt", "w") as newrainfile:
+      newrainfile.write("\n".join(new_rain_entries))
 
   per_second = 0
   if seconds_since_last > 0:
     per_second = amount / seconds_since_last
 
-  return amount, per_second
+  return amount, per_second, per_hour, today
 
 def get_sensor_readings(seconds_since_last, is_usb_power):
   # bme280 returns the register contents immediately and then starts a new reading
@@ -188,7 +215,7 @@ def get_sensor_readings(seconds_since_last, is_usb_power):
   bme280_data = bme280.read()
 
   ltr_data = ltr559.get_reading()
-  rain, rain_per_second = rainfall(seconds_since_last)
+  rain, rain_per_second, rain_per_hour, rain_today = rainfall(seconds_since_last)
 
   from ucollections import OrderedDict
   return OrderedDict({
@@ -199,5 +226,7 @@ def get_sensor_readings(seconds_since_last, is_usb_power):
     "wind_speed": wind_speed(),
     "rain": rain,
     "rain_per_second": rain_per_second,
+    "rain_per_hour": rain_per_hour,
+    "rain_today": rain_today,
     "wind_direction": wind_direction()
   })

enviro/config_defaults.py

@@ -2,6 +2,8 @@
 from phew import logging
 
 DEFAULT_USB_POWER_TEMPERATURE_OFFSET = 4.5
+DEFAULT_UTC_OFFSET = 0
+DEFAULT_UK_BST = True
 
 
 def add_missing_config_settings():
@@ -23,6 +25,18 @@ def add_missing_config_settings():
   except AttributeError:
     warn_missing_config_setting("wifi_country")
     config.wifi_country = "GB"
+
+  try:
+    config.uk_bst
+  except AttributeError:
+    warn_missing_config_setting("uk_bst")
+    config.uk_bst = DEFAULT_UK_BST
+
+  try:
+    config.utc_offset
+  except AttributeError:
+    warn_missing_config_setting("utc_offset")
+    config.utc_offset = DEFAULT_UTC_OFFSET
 
 def warn_missing_config_setting(setting):
     logging.warn(f"> config setting '{setting}' missing, please add it to config.py")

enviro/config_template.py

@@ -13,6 +13,13 @@
 wifi_password = None
 wifi_country = "GB"
 
+# Adjust daily rain day for UK BST
+uk_bst = True
+
+# For local time corrections to daily rain logging other than BST
+# Ignored if uk_bst = True
+utc_offset = 0
+
 # how often to wake up and take a reading (in minutes)
 reading_frequency = 15
 

enviro/helpers.py

@@ -1,5 +1,6 @@
 from enviro.constants import *
-import machine, math, os, time
+import machine, math, os, time, utime
+from phew import logging
 
 # miscellany
 # ===========================================================================
@@ -24,6 +25,41 @@ def timestamp(dt):
   second = int(dt[17:19])
   return time.mktime((year, month, day, hour, minute, second, 0, 0))
 
+def uk_bst():
+  # Return True if in UK BST - manually update bst_timestamps {} as needed
+  dt = datetime_string()
+  year = int(dt[0:4])
+  ts = timestamp(dt)
+  bst = False
+
+  bst_timestamps = {
+    2023: {"start": 1679792400, "end": 1698541200},
+    2024: {"start": 1711846800, "end": 1729990800},
+    2025: {"start": 1743296400, "end": 1761440400},
+    2026: {"start": 1774746000, "end": 1792890000},
+    2027: {"start": 1806195600, "end": 1824944400},
+    2028: {"start": 1837645200, "end": 1856394000},
+    2029: {"start": 1869094800, "end": 1887843600},
+    2030: {"start": 1901149200, "end": 1919293200}
+  }
+
+  if year in bst_timestamps:
+    if bst_timestamps[year]["start"] < ts and bst_timestamps[year]["end"] > ts:
+      bst = True
+  else:
+    logging.warn(f"> Current year is not in BST lookup dictionary: {year}")
+  return bst
+
+
+# Return the day number of your timestamp string accommodating UTC offsets
+def timestamp_day(dt, offset_hours):
+  # Bounce via timestamp to properly calculate hours change
+  time = timestamp(dt)
+  time = time + (offset_hours * 3600)
+  dt = utime.localtime(time)
+  day = int(dt[2])
+  return day
+
 def uid():
   return "{:02x}{:02x}{:02x}{:02x}{:02x}{:02x}{:02x}{:02x}".format(*machine.unique_id())