From c7e128d8f22522678a39a0e317833d57671c62e7 Mon Sep 17 00:00:00 2001
From: Max <m.giller.dev@gmail.com>
Date: Tue, 17 Oct 2023 17:57:32 +0200
Subject: [PATCH] Added climate logging

---
 src/climate.py | 11 +++++++++--
 src/main.py    | 24 ++++++++++++++++++++++--
 2 files changed, 31 insertions(+), 4 deletions(-)

diff --git a/src/climate.py b/src/climate.py
index 5f0c87d..fdc0149 100644
--- a/src/climate.py
+++ b/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
\ No newline at end of file
+            return None
+    
+    def get_last_read(self):
+        if self.last_read is None:
+            self.read()
+        return self.last_read
\ No newline at end of file
diff --git a/src/main.py b/src/main.py
index de00931..ba366a6 100644
--- a/src/main.py
+++ b/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"}