Disclaimer: This is my first Arduino project, and I hadn't written C programs in about 16 years
Its goal is to monitor a fish tank to check the light level, temperature and water level are ok.
If they are not, it sends SMS alerts to registered mobile phones.
A lot of parameters are configurable by sending SMS to the device, and you can also register or unregister your phone to get the alerts.
I hope to avoid the lost of fishes, shrimps, and many corals I suffered one year ago when the power went out in my apartment while I was away. If I had been warned, I could have sent someone fix that.
Although I have already built two of these devices which are running right now monitoring two different tanks, it's still a work in progress with more ideas waiting to be implemented.
The main two are:
check that the powerhead pumps are working
wifi connection to share the GSM shield between several modules to lower costs and SIM card needs, and may be log measures to a webserver.
I didn't have much time to work on this project but I have added the statistics recording.
The wifi module is used to connect to a website hosting a database to record light and temperature levels and provides graphs to display the data.
The database structure is designed to record data from any number of aquarium and owners, so at some point there will be some authentication, API key, ...etc
The website I have created to host this is still very basic : http://www.reeftankalert.com/chart.php