Do you know what is a time clock?
Time clocks were mainly used at the end of the 19th century and throughout the 20th century as a way to monitor precisely the attendance of employees in big companies and factories. Back then, it was often a paper card that the employee would slip into a machine that pinched the right time box or print it. Its concept has, of course, evolved a lot since then and most models now integrate RF or biometric technologies.
Those new machines are pretty expensive (at least $100) so we propose you to create your own fun time clock machine to monitor your employees (if you’re a CEO/HR) for less than $40 (again!) but which you can also adapt to any other use (monitor your pet’s in and outs through its pet door for instance).