NASA's new countdown clock for space missions is a lot like a football stadium display and way more advanced than the old analog one it's replacing. Freelance writer Amanda C. Kooser covers gadgets ...

You can use a microcontroller to build a clock. After all, a clock is just something that counts the passage of time. The only problem is that microcontrollers can’t track time very accurately. They ...

This 555 timer based circuit is a kind of voltmeter, also an analog to digital converter, that converts the analog input voltage to digital output pulses. The output pulse width is proportional to the ...