Quiz Buzzer Strike Back

Fourteen years ago I built my first quiz buzzer system . It worked, but the hardware was — let's say — a product of its constraints. I used every single IO pin on the Arduino, plus a 74HC595 shift register and two 74LS32 OR gate chips just to drive the LEDs. It was held together by necessity and a certain stubbornness that I think is just part of making things. I always told myself I'd revisit it.…