This unit is extremely easy to put together and with very little customisation can be used in a huge variety of applications. This project has already got a working prototype which is currently in use. I will detail the development thus far though.
The EnviroCU currently has a temperature and humidity sensor (see bill of materials) which reads the values and uses two relays to switch on some electronic goodies in order to keep predetermined values for each within a specified range.
There are four switches which enable different parameters. As I only had four different environmental conditions that were required to be met I have not added anymore switches or a method of changing the 'keep within range' values on the fly, although this would not be a very difficult addition.
The board prints some values and warnings to a small serial enabled LCD.
All of this is powered by an Arduino UNO which slots nicely on the PCB itself.
The feature list is currently quite small but I do plan on making some changes/additions. Currently all the board does is monitor and keep both the temperature and humidity within a predetermined range. There are four preset temperature/humidity ranges which can be set and then activated on the fly with four switches. Super simple stuff.
The next thing on my list of stuff to do is to completely redo the PCB. I would like to make it a lot smaller with nice little JST connections in which one would plug the sensors and outputs - some people may only have need for a single relay.
I would also like to 'embed' the Arduino onto the board rather than having an UNO sit on headers. This will make the unit a lot neater and I can also strip off aspects of the Arduino hardware that I won't be using.
Adding network communication for remote monitoring and control is also a must. A web front end would be the easiest I would think.
I also want to add more to the board. A pH sensor for instance. Also on the list is the capability to pump specified amounts of liquid, detect colour changes, presence of gases... anything environmental! Hit me with suggestions.