Clock

This was a pendulum clock that I designed for a Science Olympiad event (Event name: It's about time).

It has a period of .7s, so a table was used to quickly convert the number of swings to time elapsed.
The 6th and 7th image show the spring loaded mechanism that was used to quickly stop the pendulum when the time interval ended. This allowed us to get .1s accuracy on this device.
The 4th image shows the Arduino I used to calibrate this clock.
This clock uses an Arnfield Escapement to keep the pendulum moving.