With some colour or RGB LEDs and some simple woodwork many hobbyists have made themselves an infinity mirror, a neat device that gives the effect of an infinite distance into the future. However enthuisast Dushyant Ahuja has taken this concept one step further and created a mirror that also functions as a clock.
The RGB LEDs in his version can be controlled to display various colours which represent the time, and the alterations can be done remotely thanks to the use of a Bluetooth receiver in the clock circuitry. Futhermore with the use of an infra-red distance sensor - the clock can detect the presence of a user and turn off the LEDs, allowing use of the mirror for reflective means. It's a relatively simple yet quite outstanding project and demonstrated in the following video:
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.