[R-B] designed a 555 timer circuit to scan a keypad. Keypads are common interfaces for small projects and require row and column scanning by a microcontroller. [R-B’s] setup allows you to reduce ...

He built the NeoPixel Punk Console, a device that creates a light show without even using a microcontroller. Just a handful of 555 timers and some 74HC series logic work together to produce pulses ...