Crystal

Inside this little metal can, a thin piece of quartz vibrates when an electric field is applied. This piezoelectric effect lets it resonate at a carefully chosen frequency. An oscillator circuit supplies energy to keep the vibrations going and turns them into a steady electrical timing signal.

A crystal is a passive resonator, not a complete oscillator. A 16 MHz marking means 16 million cycles per second; it does not mean a program runs 16 million instructions per second.

In Sparkie’s workshop, a crystal helps a microcontroller keep time so its messages and little inventions stay in step.