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 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 ...

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 ...

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 ...