doc: Add comments

main.py

@@ -18,60 +18,79 @@ lora.SetAESPassword("FABC0002EEDCAA90FABC0002EEDCAA90")
 def dataHandler(data):
     # Split data on '|' separator character
     dataSplit = data["message"].split("|")
+
+    # Create object to store the data we want to send to the API
     dataToSend = {}
 
+    # Get the ID of the Drone we got the data from
     dataToSend["drone_id"] = dataSplit[0]
+
+    # Get GPRMC NMEA sentence
     dataToSend["GPRMC"] = dataSplit[1]
 
+    # Create object to store procesed NMEA sentence data
     dataToSend["gps_data"] = {}
 
     try:
+        # Parse GPRMC sentence to get processed data out of it
         gprmc_nmea2 = pynmea2.parse(dataToSend["GPRMC"])
+
+        # Get GPS status. Will be A if GPS is locked and V if not.
         dataToSend["gps_data"]["status"] = gprmc_nmea2.status
+
+        # Get GPS time
         dataToSend["gps_data"]["timestamp"] = str(gprmc_nmea2.timestamp)
+
+        # Get GPS date
         dataToSend["gps_data"]["datestamp"] = str(gprmc_nmea2.datestamp)
+
+        # Get longitude in degrees, minutes and seconds
         dataToSend["gps_data"]["longitude"] = str(gprmc_nmea2.longitude)
         dataToSend["gps_data"]["longitude_minutes"] = str(gprmc_nmea2.longitude_minutes)
         dataToSend["gps_data"]["longitude_seconds"] = str(gprmc_nmea2.longitude_seconds)
+
+        # Get latitude in degrees, minutes and seconds
         dataToSend["gps_data"]["latitude"] = str(gprmc_nmea2.latitude)
         dataToSend["gps_data"]["latitude_minutes"] = str(gprmc_nmea2.latitude_minutes)
         dataToSend["gps_data"]["latitude_seconds"] = str(gprmc_nmea2.latitude_seconds)
         
     except Exception as e:
+        # If parse failed, print error and move on
         print(e)
 
-    print(dataToSend["gps_data"])
-
+    # Create object to store sensor values
     dataToSend["sensorReadings"] = {}
 
+    # For each sensor value in the message:
+    # (we assume the rest of the string only contains sensor readings)
     for sensorReading in dataSplit[2:]:
+        # Split on the '=' character.
+        # The string before it should be the sensor name and
+        # the one after it should be the sensor value
         name = sensorReading.split("=")[0]
         reading = sensorReading.split("=")[1]
-        dataToSend["sensorReadings"][name] = reading
 
+        # Store name and value to the object we are going to send
+        dataToSend["sensorReadings"][name] = reading
 
+    # Convert data object to a JSON string
     jsonData = json.dumps(dataToSend)
 
-    print(jsonData)
-
+    # Get URL to hit for the POST request
     url = os.getenv("BACKEND_LOG_ENDPOINT")
 
     try:
+        # Send POST request with JSON data
         req = requests.post(url, json = dataToSend)
+        # Print POST request response
         print(req.text)
     except Exception as e:
+        # Print error message if we get an exception
         print(e)
 
 # 2. Listen for data
 while True:
     data = lora.Receive()
     if data is not None:
-        # On data:
-        #   a. Check if valid
-        #   b. Parse into object
-        #   c. Prepare server request
-        #   d. Send request to REST API
+        # Start a new thread to run the dataHandler method
         start_new_thread(dataHandler, (data,))
-
-# Split packet and structure into a JSON object
-# Send Post request to REST API with JSON object in request body