Added climate logging

src/climate.py

@@ -4,10 +4,17 @@ class Dht22Sensor:
     def __init__(self, pin):
         self.sensor = Adafruit_DHT.AM2302
         self.pin = pin
+        self.last_read = None
 
     def read(self):
         humidity, temperature = Adafruit_DHT.read_retry(self.sensor, self.pin)
         if humidity is not None and temperature is not None:
-            return {'temperature': temperature, 'humidity': humidity}
+            self.last_read = {'temperature': temperature, 'humidity': humidity}
+            return self.last_read
         else:
-            return None
+            return None
+    
+    def get_last_read(self):
+        if self.last_read is None:
+            self.read()
+        return self.last_read

src/main.py

@@ -1,3 +1,4 @@
+import os
 from fastapi import FastAPI, HTTPException
 from datetime import datetime
 import requests
@@ -25,10 +26,28 @@ app.add_middleware(
 
 should_run_time_loop = True
 dht22_pin = 17
+climate_log_file = "./climate.csv"
 
 matrix_display = MatrixDisplay()
 dht22_sensor = Dht22Sensor(dht22_pin)
 
+# Start background service to log temperature and humidity every minute
+async def log_temperature():
+    # If file does not exist, create it and write header
+    if not os.path.isfile(climate_log_file):
+        with open(climate_log_file, "w") as f:
+            f.write("timestamp,temperature,humidity\n")
+    
+    while True:
+        measurements = dht22_sensor.read()
+        if measurements is not None:
+            with open(climate_log_file, "a") as f:
+                f.write("{},{},{}\n".format(
+                    datetime.now().isoformat(),
+                    measurements["temperature"],
+                    measurements["humidity"]
+                ))
+        await asyncio.sleep(60)
 
 async def display_time():
     while should_run_time_loop:
@@ -46,6 +65,7 @@ async def display_time():
 
 
 asyncio.create_task(display_time())
+asyncio.create_task(log_temperature())
 
 
 
@@ -68,7 +88,7 @@ async def turn_off():
 
 @app.post("/temperature")
 async def temperature():
-    measurements = dht22_sensor.read()
+    measurements = dht22_sensor.get_last_read()
     if measurements is None:
         return {"message": "Failed to read temperature"}
     
@@ -89,7 +109,7 @@ async def temperature():
 
 @app.post("/humidity")
 async def humidity():
-    measurements = dht22_sensor.read()
+    measurements = dht22_sensor.get_last_read()
     if measurements is None:
         return {"message": "Failed to read humidity"}