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+This project is written for the Arch GPRS V2.
+
+It aims to provide a convenient method of alerting a user of humidity. However, the grove DHT22
+sensor could easily be replaced with another Grove sensor with small changes to the code.
+
+Directories:
+ * DHT 
+	- for accessing the grove
+ * DS_1337 
+	- interface to the real time clock (which is a separate chip, i.e. not part of the micro)
+ * mbed 
+	- all mbed libraries
+ * SDFileSystem 
+	- for accessing the SD card. You need to be careful to import the right one (link to my blog)
+ * USBDevice 
+	- interface to serial comms over USB (talk to it from a PC)
+ * Handlers 
+	- this is where almost all of my code lives
+
+Handlers
+The handlers have the same structure (although they do not inherit from a common base class, but they should). They have a run function, which is a state machine called from the main while loop in main.cpp. This will run continuous routines such as polling and checking if a request has been raised.
+
+A request might be raised through a common request interface that passes an enum. However this might have to be more specific. Either way, the request is then handled in the state machine.
+
+GroveDht22
+ * Takes a measurement from the DHT22 hardware at a set interval
+ * On success, sends to measurement handler
+
+SdHandler
+ * Initialises and polls the SD card, checks for errors, etc
+ * Receives requests for writing a system message to the log, or writing a measurement to CSV
+
+UsbComms
+ * Checks to see if there is a connection to a PC
+ * Receives requests to send messages to PC
+ * Diverts incoming messages from PC to appropriate handlers
+
+MeasurementHandler
+ * GroveDht22 sends a measurement to this and it decides what to do with it
+ * Stores values for schedules, thresholds, last measurements
+ * Decides if a new measurement should be sent over SMS, SD
+ * Receives a request for last measurement, state, etc, from either UsbComms or SmsHandler
+
+GprsHandler (WIP)
+ * Checks to see if there are any incoming messages, directs them appropriately
+ * Gets requests from other handlers to send an SMS
+ 
+ 
+ 
+ 
+To do:
+	* Complete basic GprsHandler
+    * Set a threshold for humidity (hardcoded to start with) and send messages at this threshold
+    * Avoid sending more than x messages per y time (so don't get bombarded with messages)
+    * Send messages to a list of numbers, not just one
+    * Send messages on a schedule, e.g. send current humidity and temp once a day, so user knows it's OK
+    * Make the above three points configurable over USB (threshold, time off, list of numbers, schedule)
+    * Respond to certain messages, over SMS, to configure and make status known.
+    * Make a base class for handlers to inherit from, so that interface stays consistent