try to smooth sensor values

sensors.py

@@ -1,6 +1,7 @@
 from time import perf_counter
 from datetime import datetime, timedelta
 from collections import deque
+from statistics import mean
 from itertools import islice
 import re
 from os.path import exists
@@ -27,19 +28,38 @@ except:
 from random import random
 from time import sleep
 
+# How many seconds to use
+WINDOW_SIZE_S = 5
+
 class Sensor():
     def __init__(self, autocorr=0.7):
+        # We won't sample at more than 10Hz, so this is safe
+        self.history = deque([], int(WINDOW_SIZE_S * 10))
+        
+        ## This is just for debugging
         self.prevval = random() * 100
         self.auto = autocorr
         self.measure = None
 
     def read(self):
         sleep(0.5)
-        return (perf_counter(),
+        return self.store(
+            perf_counter(),
             int((random() * (1-self.auto) + self.prevval * self.auto) * 100) / 100)
 
+    def smooth(self):
+        # TODO: Implement *correctly* this (take into account the time)
+        m = mean([el[1] for el in self.history])
+        return (self.history[-1][0], m)
+
+    def store(self, value, time):
+        self.history.append((value, time))
+        return self.smooth()
+
+
 class GPIOState(Sensor):
     def __init__(self, pin, transform=lambda x: 1-x):
+        super().__init__()
         self.measure = 'Switch'
 
         self.pin = pin
@@ -53,10 +73,11 @@ class GPIOState(Sensor):
             self.value = 0
         self.time = perf_counter()
         
-        return (self.time, self.transform(self.value))
+        return self.store(self.time, self.transform(self.value))
 
 class Temperature1W(Sensor):
     def __init__(self, address):
+        super().__init__()
         self.measure = 'Temperature'
         self.address = address
 
@@ -76,7 +97,8 @@ class Temperature1W(Sensor):
         if content[0].strip()[-3:] != "YES":
             print("INVALID CHECKSUM")
             return (time, None)
-        return (time, int(re.search("t=([0-9]+)", content[1]).group(1)) / 1000.0)
+        return self.store(
+            time, int(re.search("t=([0-9]+)", content[1]).group(1)) / 1000.0)
 
 if enable_sht:
     i2c = board.I2C()  # uses board.SCL and board.SDA
@@ -87,6 +109,7 @@ if enable_sht:
 
 class SHT40(Sensor):
     def __init__(self, what, every=60):
+        super().__init__()
         if what not in ("Temperature", "Humidity"):
             print("ERROR: invalid sensor value: ", what)
             return
@@ -127,7 +150,8 @@ class SHT40(Sensor):
         if reset:
             self.reset_mode()
             self.last_heat = perf_counter()
-        return (time, temperature if self.measure == 'Temperature' else relative_humidity)
+        return self.store(
+            time, temperature if self.measure == 'Temperature' else relative_humidity)
 
 class Sensors():
     def __init__(self, history=2621440):