--- a/requirements.txt	Mon Jan 20 23:36:23 2020 -0500
+++ b/requirements.txt	Sat Dec 25 00:02:03 2021 +0000
@@ -1,8 +1,12 @@
-adafruit-blinka
-adafruit-circuitpython-dht
-attrs
-pymongo
-pytz
-requests
-RPi.bme280
-smbus2
+attrs==21.2.0
+certifi==2021.10.8
+charset-normalizer==2.0.9
+idna==3.3
+pymongo==4.0.1
+pytz==2021.3
+requests==2.26.0
+RPi.bme280==0.2.4
+smbus2==0.4.1
+toml==0.10.2
+urllib3==1.26.7
+

--- a/setup.py	Mon Jan 20 23:36:23 2020 -0500
+++ b/setup.py	Sat Dec 25 00:02:03 2021 +0000
@@ -2,12 +2,10 @@
 
 setuptools.setup(
     name='weatherlog',
-    version='0.2.2',
+    version='0.3.0',
     packages=setuptools.find_packages(),
     python_requires='>=3.7',
     install_requires=[
-        'adafruit-blinka',
-        'adafruit-circuitpython-dht',
         'attrs',
         'pymongo',
         'pytz',

--- a/weatherlog/daemon.py	Mon Jan 20 23:36:23 2020 -0500
+++ b/weatherlog/daemon.py	Sat Dec 25 00:02:03 2021 +0000
@@ -43,10 +43,14 @@
 
 
 class SensorType(enum.Enum):
-    DHT22 = 'DHT22'
     BME280 = 'BME280'
 
 
+_SENSOR_FACTORIES = {
+    SensorType.BME280: reader.BME280Reader,
+}
+
+
 @attr.s(auto_attribs=True, frozen=True, slots=True)
 class _Config:
     # The directory to store reading data in.
@@ -77,12 +81,11 @@
     writer = http_writer.HTTPWriter(config.url, config.auth)
     log = logger.BufferedLogger(config.directory, writer)
 
-    if config.sensor is SensorType.DHT22:
-        rdr = reader.DHT22Reader()
-    elif config.sensor is SensorType.BME280:
-        rdr = reader.BME280Reader()
-    else:
-        raise AssertionError('Unknown sensor type')
+    try:
+        factory = _SENSOR_FACTORIES[config.sensor]
+    except KeyError:
+        print(f'Invalid sensor type {config.sensor}.')
+    rdr = factory()
     run(rdr, log, writer)
 
 

--- a/weatherlog/reader.py	Mon Jan 20 23:36:23 2020 -0500
+++ b/weatherlog/reader.py	Sat Dec 25 00:02:03 2021 +0000
@@ -7,9 +7,7 @@
 import time
 import typing as t
 
-import adafruit_dht
 import bme280
-import board
 import smbus2
 
 from . import types
@@ -24,49 +22,6 @@
         raise NotImplementedError()
 
 
-class DHT22Reader(Reader):
-    """A reader for the DHT22 sensor, which attempts to make good readings."""
-
-    def __init__(self, pin: t.Any = board.D4):
-        """Initializes a DHT22 reader connected to the specified pin."""
-        self.device = adafruit_dht.DHT22(pin)
-
-    _TEMP_C_EPSILON = 0.51
-    _RH_PCT_EPSILON = 1.01
-    _NEW_READING_SECS = 2.5
-
-    def read(self) -> types.Reading:
-        """Reads a value from the sensor.  This will block until done."""
-        temps: t.List[float] = []
-        humids: t.List[float] = []
-        while True:
-            temp, rh = self._read_once()
-            if _is_reasonable_temp(temp):
-                temps.append(temp)
-            if _is_reasonable_rh(rh):
-                humids.append(rh)
-            try:
-                return types.Reading.from_now(
-                    temp_c=_last_stable(temps, epsilon=self._TEMP_C_EPSILON),
-                    rh_pct=_last_stable(humids, epsilon=self._RH_PCT_EPSILON))
-            except ValueError:
-                # There is not yet enough data to see if the value is stable.
-                # Wait for a new reading.
-                time.sleep(self._NEW_READING_SECS)
-
-    _RETRY_WAIT_SECS = 0.5
-
-    def _read_once(self) -> t.Tuple[float, float]:
-        """Tries very very hard to read a single value from the sensor."""
-        while True:
-            try:
-                temp, rh = self.device.temperature, self.device.humidity
-                if None not in {temp, rh}:
-                    return temp, rh
-            except RuntimeError:
-                pass  # This will happen a lot.  Just try again.
-            time.sleep(self._RETRY_WAIT_SECS)
-
 
 class BME280Reader:
 
@@ -81,39 +36,3 @@
             temp_c=reading.temperature,
             rh_pct=reading.humidity,
             pressure_kpa=reading.pressure / 10)
-
-
-def _last_stable(
-        vals: t.Iterable[float],
-        *,
-        epsilon: float,
-        count: int = 3) -> float:
-    """Returns the last stable value from the given sequence.
-
-    The stable value is defined as the last value for which there are `count`
-    values in the sequence within `epsilon` of some value.  This is used to
-    eliminate misread values in the sequence, usually due to timing issues.
-    The `count` values need not be in sequence.
-
-    The value returned is the median value of the group (or the next-to-median
-    in the case of an even count).
-    """
-    buckets: t.Dict[float, t.List[float]] = {}
-    for v in vals:
-        buckets.setdefault(v, [])
-        for bucket, bucket_vals in buckets.items():
-            if abs(v - bucket) <= epsilon:
-                bucket_vals.append(v)
-            if len(bucket_vals) == count:
-                return sorted(bucket_vals)[count // 2]
-    raise ValueError('No stable value.')
-
-
-def _is_reasonable_temp(temp: float) -> bool:
-    """True if the temperature is a reasonable level for the boathouse."""
-    return -40 <= temp <= 60
-
-
-def _is_reasonable_rh(rh: float) -> bool:
-    """True if the relative humidity is plausible."""
-    return 0 <= rh <= 100

--- a/weatherlog/reader_test.py	Mon Jan 20 23:36:23 2020 -0500
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,51 +0,0 @@
-import itertools
-import unittest
-
-from . import reader
-
-
-class ReasonableTest(unittest.TestCase):
-
-    def test_temp(self):
-        for good_temp in (-40, 0, 20, 36.4, 40, 60):
-            self.assertTrue(reader._is_reasonable_temp(good_temp))
-        for bad_temp in (-273, -41, 69):
-            self.assertFalse(reader._is_reasonable_temp(bad_temp))
-
-    def test_rh(self):
-        for good_rh in (0, 10.0, 55.5, 90):
-            self.assertTrue(reader._is_reasonable_rh(good_rh))
-        for bad_rh in (-1, 101):
-            self.assertFalse(reader._is_reasonable_rh(bad_rh))
-
-
-class StableTest(unittest.TestCase):
-
-    def test_not_enough(self):
-        with self.assertRaises(ValueError):
-            reader._last_stable((), epsilon=1.0)
-        with self.assertRaises(ValueError):
-            reader._last_stable((1.0,), epsilon=1.0)
-        with self.assertRaises(ValueError):
-            reader._last_stable((1.0, 1.5), epsilon=1.0)
-        with self.assertRaises(ValueError):
-            reader._last_stable((1.0, 1.0, 1.0), epsilon=1.0, count=4)
-
-    def test_wild(self):
-        perms = itertools.permutations((1.0, 99.9, 1.2))
-        for perm in perms:
-            with self.assertRaises(ValueError):
-                reader._last_stable(perm, epsilon=0.5)
-
-    def test_good(self):
-        perms = itertools.permutations((1.0, 1.3, 1.5, 66.6, -1))
-        for perm in perms:
-            self.assertEqual(reader._last_stable(perm, epsilon=1.01), 1.3)
-        perms_less = itertools.permutations((1.0, 1.5))
-        for perm in perms_less:
-            self.assertEqual(
-                reader._last_stable(perm, epsilon=0.51, count=2), 1.5)
-
-
-if __name__ == '__main__':
-    unittest.main()