Comprising a microprocessor, an LCD, a 32.768-kHz crystal, and little else, the basic countdown-timer circuit in Figure 1 operates from a commonly available CR2032 lithium-coin-cell battery. Based on ...

“Arduino Self-Timer” project presented here is a low-component count 60 seconds countdown timer. It can be powered from a 9V compact battery or suitable Arduino AC mains adaptor. Working of the ...