Wattmon is getting ready to be released! As the programming of version 1 is coming to a close the possibilities and opportunities for using wattmon seem endless. I have already installed a wattmon to control a three phase bore well pump in a remote location over 3G. It uses level sensors to control the pump and ensure the tank is never empty, this will shortly be interfaced with a modbus compatible power meter to log energy usage, and voltages and email somebody when things go wrong.
From basic energy metering, wattmon has grown to become a tool for monitoring and control of water! And this took no time to do since everything was set up using actions. Actions in wattmon let you switch on or off inputs, send en email, access a URL, or set a variable based on a set of trigger conditions. For example, the pump setup has one action to switch on a digital output when two digital inputs (high and low tank level) are off. A second action switches the output off when the high water level sensor is on.
In a more complex example, at our office we have a charger which is controlled by a wattmon relay. Several actions determine when the charger is switched on to maximise the usage of the solar panels. At night, the relay switches on when the battery percent drops below 90 and off again when it reaches 95. This could be set to any value but that's just what works for us. During the day a different set of actions are active and the relay only switches on when the batteries go below 50% which could happen on a cloudy day.
An easy to use interface makes it possible for anybody without programming knowledge set up detailed conditions to trigger actions, opening wattmon up to the world of home automation. Since most home automation controllers are sold for over 350 US dollars, wattmon could find a market in the low end home automation sector where basic control is required but budget is limited.
The temptation is to keep adding features to this already versatile device to try and foresee all scenarios but there comes a time when one must freeze the feature set. The WattmonSolar package which is installed by default on the box is specifically designed to monitor off grid solar setups and battery banks. Dual current sensors monitor both in and outbound current and battery voltage, and calculate battery percentage remaining. Logs and graphs provide information on daily generation and consumption, as well as voltage and percentage throughout the day. As this is the primary purpose of wattmon, this is the feature set that is most important. For the hobbyist, a whole other range of features are available.