[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 red… ...

Droplet and StackAR, developed by MIT’s Media Lab, allow users to set timers or program an Arduino using light-based communication. By pressing the tool against a screen, flashes of light can ...