In most keypads, pressing a key closes a contact that bridges two lines in an xy matrix. If you use a microcontroller to detect a key closure, checking the states of (x+y) lines requires an equal ...

Traditionally, interfacing a microcontroller with an n-by-m keypad required n + m of the microcontroller's I/O pins for keypad scanning. Keypad designs that conserve microcontroller pins have been ...

[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 the ...

If you enjoy building electronic circuits, projects and devices, you might be interested in a new component launched by Adafruit this week in the form of the new Adafruit 4×4 elastomer keypad. The ...

If you would like to build your very own Macropad shortcut keypad you may be interested in a new project published to the Hackster.io website by member Naveen. The builder is classed as an ...

This idea builds on a previous IFD, "Connect Any Keypad With Any Microcontroller Using Only One Pin" (electronic design, May 1, 1998, p. 126), where a 555 timer connects a keypad switch matrix to a ...

Voice assistants and smartphones are often the go-to interfaces for modern smart home systems. However, if you fancy more direct physical controls, you can go that route as well. To that end, [Salim ...