Aquarium enthusiasts and others who require timed dosing of liquid into a tank of some sort will find the following project of interest. After starting a new planting tank, Deven Rich created an automated system that controls three pumps using an Arduino and a real-time clock IC. This allows scheduled dosing of the required amounts for the tank, and removes the worry of forgetting to do so manually. Apart from providing the code and schematic, Deven has documented the hardware and mounting of the project which makes it easy to follow along - for example:
The most important part of any clock project is the inclusion of an accurate real-time clock IC. Here at Freetronics we have the Maxim DS3232 real-time clock IC module:
Apart from keeping accurate time for years due to the temperature-controlled oscillator and having a tiny coin-cell for backup, it is very simple to connect to your Arduino project. A driver library allows your program to easily set or read the time and date. Perfect for clock projects, dataloggers or anything that needs to know the date and time. Furthermore it contains a digital thermometer and 236 bytes of non-volatile memory to store user settings and other data. For more information, check out the module page here.