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74-Series Clock Gets A MEMS Heart

[Erik van Zijst] has had an extended occupation as a programmer, however lacked an figuring out of what used to be going down at a naked steel stage. After development a couple of common sense gates out of transistors to get a really feel for electronics, he got down to construct a operating clock the use of 74-series common sense. Naturally, it used to be somewhat the journey. 

The challenge begins out as many do at the breadboard. The considered necessary BCD counters and 7-segment presentations had been sourced, and the whole thing used to be attached up with a cavalcade of colourful hookup wires. A 32.768 KHz crystal used to be pressed into carrier to generate the clock sign, divided right down to get a 1Hz output to power the seconds counter that may then run all of the clock. [Erik] then had to be told some simpler electronics abilities, to maintain debouncing buttons for the time environment circuit.

With the clock now practical, [Erik] determined to take issues additional, aiming to construct one thing extra tough and usable. An computerized brightness keep an eye on used to be created the use of a 555 to run a crude PWM dimmer for the LEDs. Additionally, a PCB used to be designed to switch the brief breadboard setup. This resulted in issues of the oscillator that [Erik] couldn’t somewhat work out. Rather than proceed at the identical trail, he modified tack, as an alternative changing the quartz crystal with a contemporary MEMS oscillator that solved the issue.

It’s a super take a look at assemble a operating clock from naked common sense, and one that serves to remind us simply how advanced even a apparently easy software can also be. We’ve observed different from-scratch builds prior to too, like this 777-transistor clock, or this sexy stacked design. Video after the damage.